Background technology
Most of audio frequency playback systems use electro-mechanical loudspeaker to come acoustics ground to reproduce sound signal.Loud speaker electric, mechanical, and acoustic properties usually poor than desirable, cause distortion, response abnormality, and other dyeing (coloration) of sound.Multiple technologies are used to compensate the characteristic of loud speaker, so that improve the audio quality of being felt.
Use and found in the literature the function or the behavior model of loud speaker actually, be used to form such compensation.The good example how model and modeling process work is in " ActiveEqualization of Loudspeakers (the active equilibrium of loud speaker) ", and Speaker Builder describes in 1997 2 months.Model reinforcement technique language, and usually plan imitation or analog speakers system acoustic response to electrostimulation.Model produces or comprehensively usually is from forming the function grouping of element, represented all or part of of loud speaker in these function set of packets, perhaps movement as all or part of of loud speaker.Coil and magnet segment become by resistor, inductor, capacitor, back-EMF generator and other and are transformed the represented motor of part.The combination of braking, reach the factor the mechanical loss such as volume of air, moving-mass, acoustics loading, magnetic can be analyzed, and be simplified as LCR resonator network or circuit.The most frequent is, the electromechanics in the model after the expressed conversion, acoustics, and the machinery expression further simplified or be reduced to less element.Model still responds as loud speaker, but the part of formation model is not equal to for the accurate behavior of the part that forms loud speaker.Therefore, when the part of loud speaker was changed, the zero phase that conventional model neither plans can not carry out at parameter compensated.
People can describe the frequency response of model of good design and the feature of other attributes, and reverse this frequency response and other attributes, and realize that the linear phase of loud speaker proofreaies and correct.This technology is how many energy starting point effects really, are used for single loudspeaker design but special use, dumb circuit or the special process of its dependence conventional model limit it.Some high-quality intersection (crossover) network that is configured to division signals frequency spectrum in a plurality of drivers may have certain conjugation response corrections like this.
Low-frequency resonant promotes (boost) and designs for most of loud speakers specially.Usually make conventional model represent to quantize and measurable acoustics behavior and other loudspeaker design factor of influencing bass response.The attribute of mechanical realization and air is determined frequency, resonance loss and the configuration influence to exporting from the acoustics of loud speaker.Can design and realize good approximation by this way to zero phase conjugation or same order correction for wider frequency.Several assemblies need mate the resonance behavior, but these assemblies are all interact with each other when the different loud speakers with similar notion and design are regulated.Therefore, operation is strictly controlled by parameter, because must recomputate adjusting to produce needed minimum phase of the new loud speaker of the most accurate reproduction or accurate coupling according to model.When adding more timing, INTERACTION PROBLEMS becomes and is difficult to overcome.When regulating, must be with experiment method Adjustment System or analytical model.Therefore, the lumped model process that is used to respond graduation is the intrinsic design of particular speaker.Must redesign this process for other loud speaker.
The tradition curve-fitting method may require to set up a hundreds of data point and corresponding adjusting, and the frequency response that requires a plurality of assemblies or a large amount of processing power coupling to be obtained.Analogy method is unpractiaca, and digital process needs a large amount of calculating with large-scale architecture to realize this point.Under the situation to the knowledge of loud speaker and operation thereof not, the both can not provide phase place accurately response or the hiding correction described after a while.Do not having under the situation of model, the effort that amplitude, time and phasing is combined according to measured response becomes very difficult.
The most important behavior of some of loud speaker (but about acoustics sensory effect) can not come modeling or realization by conventional method.Such behavior comprises that standing wave disturbs, mode is disperseed (modal breakup) and coupled resonance and from the non-linear consequence of such potential interactional acoustics and mechanical behavior.
The random motion of counterproductive or dispersion may take place.Even when average response kept smooth or identical with other frequency of reproducing, energy also can be released when signal changes or stops also increasing gradually during the signal stimulus.In addition, need to consider with the rigidity (stiffness) of motion parts and be used for other relevant space factor of high-frequency decoupling away from the motion of driving voice coil loudspeaker voice coil.In these factors any can both produce source movement to binaural, postpone energy release and phase error.Usually, such destruction response may be sightless, perhaps is difficult to be explained by conventional microphone and frequency spectrum analyser calibration steps.
For example, the unnecessary response that is produced by node (nodal) and standing wave behavior influences stabilization time, direction behavior and the radiation output of loud speaker.Usually, these responses cause that the sensation of information signal changes, and change yet may can't see or can not discern these sensations from response diagram.Mechanical movement with big stored energy may out-phase at transducer different piece place.Acoustics output may seem it is smooth, but human binaural can arrive its source to the behavior localization, and the sensation after changing can make three-dimensional imaging degenerate.
Usually, mechanical disturbance can hear, but cannot see from the response measurement that frequency of utilization scanning and microphone carry out or be difficult to explain this mechanical disturbance.The part of radiating surface can be with respect to the vibration of the out of phase of other parts relation, thus motion in its additivity acoustics output and the transducer and related energy store compare low.When the signal at nodal frequency place changes and stops suddenly, the release of stored energy can with other signal interactions at the different frequency place.The beat sound between two frequencies that is produced is that can hear and very horrible.Sound with the frequency spectrum in the interfering frequency scope may seem than ringing and being granular.Human binaural can be disturbing localization may further damage the stage illusion from multi-loudspeaker stereophonics thus from its surface of rebounding to driver or direction lobe.For this situation, fully decay produces the frequency of mechanical disturbance, with the unshielded reproduction that prevents that the result from responding.Experience shows that the needed sharp-pointed dark trapper (notch) of realization this point is removed emending frequency enough energy on every side to produce nasal sound.If revise this inappropriate correction to realize flat response, mechanical sounds keeps with potential undesirable balance aberration so.
With transducer, shell, and the resonance device of expansion bass response, construct a plurality of little loud speakers as port or passive radiator.Usually, these partial design become implementation efficiency, frequency response precision, bass extension and can receive actual and economic compromise between the distortion.Cheaply, the designer of low power system generally selects greater efficiency, so that the step-down amplifier requirement, and the relevant cost of power supply and encapsulation.Compromise situation exposes a plurality of undesirable behaviors aspect.
Certain of most of conventional loudspeakers bearing calibration applies amplitude equilibrium changes with graduation and the response of expansion from loud speaker.Regulate and realize by ear sometimes.In order quantitatively to regulate, people must obtain relevant data.The spectrum analysis that most of ordinary skills of realizing this point use self noise to stimulate.Then, how response diagram or demonstration indication regulate equalizer.Respond based on postponing arriving from first of loud speaker of reception or sampling window, and can remove the indoor interference of high frequency to produce similar anechoic data than the mature technology energy measurement.Purpose is to catch and indoor audience or the relevant information of standard measurement operations, in this standard measurement operations, specifies a test microphone usually, and places it in from one meter of loud speaker.Such technology produces the response that the single-spot testing microphone sounds balance.One or more known systems come one of a plurality of loud speakers aligning are listened to the position by regulating path or time delay, thereby surpass this technology a little.
Other technologies provide transient response waveform, waterfall figure or a series of spectrogram after an incident.Obtain group delay and the information relevant with the time.Such data need explanation, and limited for the purposes of frequency response smoothing (leveling) operation.Some behavior responses can be discerned, but more information must be known about loud speaker.For this reason need be such as the measuring element equipment accelerometer, difference acoustics probe and the microphone.Detecting instrument can be placed near a suspicious actions place, and how is moved with probe response with change in location.Can be on all suspicious frequencies tuning or slow inswept weighting trap, subjectively observe noise simultaneously and produce.Need be about part dimension, listen to position and floor, bookshelf, possible computer monitor, maybe may be that other of a part of listening to environment are got involved the more information of objects.Need other technologies specification or expression to finish the conjugation model that to realize that accurately proofread and correct time phase.
Human operator can be born and aim at the role by regulating the setting of graphic equalizer, parametric filtering device of manual tuning or change intersection (crossover) equipment.The industry simulated assembly is realized these functions, but they are restricted.Graphic equalizer has up to 31 frequency bands or resonator, and parameter equipment comprises several tunable filters, and a few has variable cross and tiltedly limits (shelf) function.Need more a plurality of filters.The combination of figure and equalization parameter device can not provide enough points of big quantity, and accurate phase place and response can not be provided, and compensates the complex behavior from loud speaker effectively.Perhaps proofread and correct the characteristic frequency that do not match, thereby produce phase error, perhaps the lazy weight of filter is enough handled stabilization time and Stationary Wave.Group delay distortion, time phase error, imperfect correction and other shortcomings may surpass other improvement.
The DSP filter can produce the much more filter segment that can realize than analog circuit.Utilized special-purpose control to generate software and used the graphic equalizer of forming by the part of controlling from parameter, to produce the room response smoothing.Such process is difficult to set up, because the room disturbs mutually with the identification of important behavior indicant.Do not have its input, the conjugation response corrections is exactly impossible.Standing wave and node distortion correction can be formed by this system.Yet required compiling that is difficult to carry out and the processing of motion compensation trapper is difficult on the parameter.Single-point response pick-up and FFT have been used to the data of the system of being input to probably.Such method can not respond or provide generation that loud speaker is produced true conjugation and respond needed time phase of information.Analytical system as MLSSA, can be removed the room and disturb from measure, and can produce frequency, transient state and steady-state response data from a speaker system.Yet, must explain mass data from these measurements.The multiband graphic equalizer is not to set up a kind of good selection of proofreading and correct.
Dsp system can produce many with irrealizable parametric filtering device of analog circuit and the process relevant with the time economically.The extensive dsp system of tradition is not almost measured the device of discerning and select the loud speaker behavior unusually by other.Their frequency domain response may add phase error and ignore delay stable state energy.Listening to position sound for one may improve, but will degenerate for other position sound.More possible is, reproduces sound and will change and do not have a conclusive improvement.
So the technical staff relevant with audio reproduction has realized that needs a kind of system and method, is used for the complete behavior modeling to acoustic reproduction device, so that the conjugation that can produce for the acoustic reproduction device response responds.Also have realized that the needs that to revise the system and method for conjugation response to a kind of employing.In addition, also have realized that the needs of system and method that compensation are independent of the audio reproduction of the environment that wherein will listen to sound.The present invention satisfies these needs and other needs.
Embodiment
Following description concentrates in the application of the present invention for speaker system.Yet, the invention is not restricted to such application, and can be applied to other sound transmissions and reproducer, those as being narrated at the specification end.
Referring now to accompanying drawing, wherein like numerals will is indicated similar or appropriate section in all figure, and particularly for Fig. 1, shows a kind of system 10 of the present invention that comprises.System 10 comprises a signal source 12, is used to provide electroacoustic signal frequently.Signal source for example can be a CD-audio player.Output 14 from signal source 12 is input to a bucking-out system 16 that adopts detailed features of the present invention and aspect.Output 14 is handled by bucking-out system 16, to produce an electroacoustic after the compensation that is fed into a power amplifier 19 and a loud speaker 20 signal 18 frequently.
With reference to Fig. 2, bucking-out system 16 adopts a plurality of filters 24, filter 24 or individually or in combination present the indivedual compensation responses of simulation by the frequency that various machinery, acoustics and electromagnetic assembly presented, time and the phase response of loud speaker.Be associated with each of filter 24, and thereby what be associated with each of compensation response is one or more customized parameters 22.Use DSP or analog circuit to produce filter 24.Digital Signal Processing is preferred realization, because the analytical model of loud speaker behavior is converted into the mathematical synthesis technology that is used to design digital system easily.Analog circuit has the distortion that is based upon in the cascaded architecture.Therefore, be to isolate and do not have when interaction and can use when being connected in parallel circuit element only when board design person knows in behavior response, the realistic simulation of bucking-out system 16 realizes being only possible.Some parameters 22 are regulated the one or more parts interactions with bucking-out system.A kind of Digital Implementation provides compiling that utilization may be provided with or the ability of calculating these relations on demand.When by the computer-controlled compensation system, set up adjusting and seem simple and directly perceived.
These calculating can zoom to especially relevant with size, movement properties or acoustic radiation behavior among other things parametric variable, feature or design aspect with each of adjustable compensation response.Time delay, the maximum drift limit, wavelength relationship, node and standing wave frequency, edge reflection and the like attribute of loud speaker can be regulated and use to bucking-out system.Bucking-out system is not compiling or reduces speaker element producing a lump responding system, and is to use the of equal value and no interactional filter string of minimum phase.
The typical Whole Response of little loud speaker is illustrated among Fig. 3 f.Place, top at Fig. 4 repeats identical response.Fig. 3 a-3e represents and the loudspeaker assembly relevant a plurality of individual responses of combination with generation Whole Response curve.Fig. 4 a-4e represents through a plurality of customized parameters, for example L
S, H
S, L
X, H
XDeng, regulate to produce a plurality of indivedual compensation responses of a plurality of conjugation responses.Describe the attribute of parameter below in detail.As shown in Fig. 4 f, indivedual conjugation response combination are to produce or a whole conjugation response.Level and smooth response of the combination results of whole loudspeaker response (Fig. 3 f) and conjugation response (Fig. 4 f).
As seen, it all is conspicuous that first and second of high and low frequency ends flex point from Fig. 3 a and 4a.These points on curve are identified for L
X, L
S, H
X, and H
SFrequency.When voice coil loudspeaker voice coil length and motion acoustic compliance (motional compliance) when ability is known, be similar to a kind of calculating or the chart represented among Fig. 5 so and can help to be identified for L
PReasonable frequency and amplitude.Handle H in a similar fashion
PRelevant flex point, by and frequency representation in Fig. 3 b and 4b.L
PAnd H
PThe amplitude setting have subjective Power Processing and weighting compensation problem.
The self-resonance of the driver of operating in its shell body can be measured or be calculated to produce W
0Can be by conventional model with the relevant Q of execution mode measurements and calculations
0With | A|
0Be provided with, condition is to have removed the acoustics coupling factor.Fig. 3 d and 4d represent this bass compensation.
In conventional model, seldom use the expression of mechanical resonant, for example W
1The HFS of Fig. 3 d and 4d is represented, from W
1Acoustic response sum of errors dyeing can be by setting | A|
1Remove.Notice resonance on every side, and can select to preset or default Q, to compensate the typical resonance behavior model of related loud speaker material.
Node and interference behavior are conspicuous in Fig. 3 e.The relevant issues that usually are called " awl is (conecry) " that other examples in Fig. 6 have disclosed the node jump, disturb and cause because of ear-piercing, the sound that pollutes.Can represent that with those the similar waterfall figure or the MLSSA that are illustrated among Fig. 7 such high-energy moves the typical frequencies of interference and postpones dispersion results.Hiding compensation trapper W among Fig. 4 e
CC1And W
CC2Remove these frequencies and energy storage problem.
Add slope or inclination EQ to realize best audience's hobby.Fig. 3 c and 4c represent behavior and correction.For subjective balance can be added extra downward-sloping.
That if can see is such, and generally, each can carry out very good conjugation across few 12 to 16 adjustings to 8 bit resolutions and proofread and correct.Representative frequency Response Table from two speaker driver unit is shown among Fig. 6.Note, as by roll-offing of the response curve of lower end indicated, with L
PRelevant W
0With the second flex point response loss, because driver is operated in very large housing.In addition, other parameter correlation feature is conspicuous, and can calculate adjusting by these curves.
Following parameter allow loud speaker complex frequency, phase place, and the generation of time response, simulation or with its conjugation.These customized parameters 22 and its operation energy approximate zero phase response, the output of expansion bass, and remove mechanical sounds (can use other parameters in a similar manner) from loud speaker.Can digitally or use active or passive analog circuit, as RC circuit, simulation resonator or resemble state variable filter or the population parameter circuit of biquad filter and so on, carry out indivedual compensation.
Term
|
Abbreviation
|
Describe, concern
|
The low intersection |
L
X |
Swept area, acoustic compliance, volume of air, acoustics are coupled, reach B
LFactor.First flex point under the every octave of (+/-6dB)
|
The high intersection |
H
X |
Quality, swept area relation, rigidity, B
LFactor.(every octave+/-first flex point under the 6dB)
|
The low tiltedly limit that promotes |
L
S |
Design limit, phono-equalizer unit, (XdB stops slope) |
The high tiltedly limit that promotes |
H
S |
Design limit, Power Processing, useful response linearity (XdB stops slope) |
Low crest |
W
L |
Be used for the lifting of the second coupling flex point.Be used for the hiding compensation of high pass or low-frequency limit filter.(default cut-off slope, XdB crest) |
High crest |
W
H |
Be used for the lifting of second high-frequency loss.Be used for the hiding compensation of low pass or high frequency limit filter.(default cut-off slope, XdB crest) |
Motor |
B
L |
Power, back electromotive force, induction factor.The influence of modulated response and parameter value |
Bass resonance |
W
0 |
Volume, acoustic compliance, area, damping, B
LFactor.(frequency, Q, amplitude)
|
Term
|
Abbreviation
|
Describe, concern
|
Port is tuning |
W
B |
Bass tuning model (traditional) (being used for the input of double-tuned filter model) |
Mechanical resonant |
W
1, W
2, to W
n |
The part of system comprises plate, awl basin, surround, reaches dome (dome) (frequency, Q and amplitude) |
Stable state resonance |
W
CC1, W
CC2, to W
CCn |
Node mode: standing wave, bell pattern, delay coupled interference (weighting trap frequency, Q and amplitude) |
Coupling factor |
| A|
1, | A|
1... | A |
n |
Resonance numerical value (always adjustable part of resonator+/-dB) |
Loss factor |
Q
0, Q
1... Q
n |
Resonant bandwidth (default or regulate may+/-dB) |
Tilt |
DB |
Leave frequency equilibrium output: B
LFactor.Subjective balance and default placement balance
|
Wave interference |
Td |
Size: housing, floor, wall, loud speaker and audience place. |
Balanced |
EQ |
User operation: the room, other are traditional |
Power |
P
W |
Maximum low frequency inputs or outputs.Simulation ratio or threshold switch detector |
Mode switch |
SW1, SW2, etc. |
Dynamic process: operation or selection |
Somewhere between 8 and 32 parameter regulation can be used for programming bucking-out system and the operation suitable compensation process.Because parameter is relevant with the behavior aspect with special-purpose physics, so feel needed much smaller than covering the mankind for the data demand of adjustable range and precision.Eight bit resolutions are suitable for the majority in these, thereby the single data flow characterization of a 1-5k position comes a very complicated response of self model.Being described below of above parameter.
Low (the L that intersects X ) or the acoustics couplingThe size of radiating surface is depended in the output of-low frequency.Every octave 6dB loss from this relation is compensated inherently by the awl basin motion that increases, and condition is to compare less with drive signal from the counter voltage of electric machine structure.If acoustic compliance is unlimited and motor produces power and do not have speed limit, then this Utopian configuration has flat response.Have volume of air, mechanical stiffness, and the real system of speed limit have two actual crossover point, wherein response stops smoothly, converges to the 6dB/ octave, arrives the loss of 12dB/ octave bass then.Usually, second flex point is near the minimum useful response of loud speaker, and usually becomes and can't carry out compensation.The Control Parameter that is used for this compensation is that unit is the frequency of Hz, and conjugation response (specific compensation) for reducing frequency is+lifting of 6dB/ octave.This first response flex point place that is lifted at from loud speaker begins.The value that is used for this parameter can be by applying a test signal to loud speaker, for example sine wave, and measurement responds and measures.According to the physical characteristic of loud speaker,, also can calculate this value as awl basin and mass of coil.By the loud speaker model, as the standard Theil/Small model that provides by loud speaker manufacturer, also can derive this value.
High (the H that intersects S ) or quality acoustic compliance factorThe size and the speed of radiating surface is depended in the output of-high frequency.Usually, compare less near the wavelengths of interest of the frequency of ending with the motion parts of the loud speaker that produces output.Under awl rigidity of cone material and the damping properties affect lower frequency from this transition of the radiation on whole surface.The frequency radiation is high more, the closer to voice coil loudspeaker voice coil.The final 6dB/ octave that produces with frequency increase motion of moving-mass reduces.Leakage inductance from electric machine assembly is added other acoustic compliance in the system to, carries out second flex point that the 12dB/ octave descends to produce under the highest actual frequency.These losses combine with the swept area that reduces, and produce reducing of acoustics output.Under lower frequency, expertly two kinds of relations of balance are to produce smooth acoustic response.The Control Parameter that is used for this compensation is that unit is the frequency of Hz, and the conjugation response is to promote along with frequency increases the 6dB/ octave.With with intersect at the value that similar mode energy measurement described above or calculating are used for this parameter for low.
Low tiltedly limit (Low Boost the Shelf) (L that promotes S )-from L
SMaximum lift be restricted to from booster output, awl basin motion, voice coil loudspeaker voice coil length, shell dimension, and the actual greatest limit of the bass extension of plan.These require contradiction and interaction, and for example long voice coil loudspeaker voice coil requires bigger amplifier and suspended portion.For example, the coil of a prolongation can provide bigger linear drift and bass output potentiality, but efficient reduces, unless increase the magnetic flux energy from magnet.Increase drift and require bigger surround, and must increase awl basin diameter to keep identical swept area and bass output.Bass resonance is low more, and loud speaker must be physically big more, and the moving-mass that increases further reduces efficient.If limiting amplifier power, then housing becomes bigger.L
X, W
0(describing below) and L
SThe manipulation of parameter has produced effective or extended response loudspeaker design down at much less compromise.In addition, can make L
SParameter change or to follow the tracks of different volume control setting and program dynamic, thus speaker system can be operated under broad range of conditions near its maximum capacity.L
SParameter is designed the influence with structural factor, and these factors comprise swept area, acoustic compliance, reach the force factor of drive motors.The parameter that is modeled can be followed the tracks of the variation of these factors with very little interaction.L
SParameter is+/-dB.L
SParameter setting can be measured after tested by the experiment with tradeoffs and be determined.
High tiltedly limit (High Boost the Shelf) (H that promotes S )The actual maximum performance of-loud speaker and power handling capability limit maximum high-frequency and promote.In some applications, can be H
SParameter is arranged to reduce the perceptual distortion from program source rather than loud speaker.About L
S, can make built-in function that variation is set by order.Other parts when system comprise program material, are forced in when its maximum linear power capability is above operates, and this feature can help to cover the distortion of increase.H
SParameter is+/-dB.It is provided with preferably measures sample plot to determine after tested.
Low crest (W L )It is preferred usually that-resonance bass ends.Balance record for this reason, and most of loudspeaker design are become to have the self-resonance bass strengthen.Generally, big loud speaker has than low resonant frequency, and the audience relates to this pass to value and fastens.W
LParameter is provided at the natural self-resonance (W of loud speaker itself
0) following low-frequency resonant lifting.As low Q
LThe compensation response descends and removes W
0During effect, speaker system just looks like its electric more like that and acoustics earthquake work.It can not have balanced little loud speaker rumbling or case sound (box sound).In order to prevent undue distortion and power extraction, at W
LFollowing signal is decayed rapidly, and the high pass filter that relates to is followed the tracks of W
LParameter is provided with.This effect has with weighting and compensates similar subjective factor, because the frequency below cut-off frequency may be small and weak, but as the W that can't help the human auditory
LStill can hear during other sound masks in the critical band.Generally, regulate and be provided with W
LCrest is so that for maximum reproducing condition power controlling and distortion.For other conditions, can close high pass or inferior bass filter, and move or change (the L of low pass filter
P) part and do not have tangible subjective result.As described, can dynamically modulate W
LParameter is with the expansion bass or reduce distortion.The adjusting of the response of low pass filter comprises peak frequencies (W
L) and unit be the amplitude of dB | A
L|.Hinted default Q
LBe provided with.
High crest (W H )-resonance be by being preferred, and to compensate second by flex point, perhaps it can be used for the restrict reproduction bandwidth.First uses the energy extended response and reduces group delay distortion.Bandwidth constraints may be needed so that the program of distortion sounds better.Crest resonator and tracking high pass filter (H
P) to operate with low frequency crest system similar mode.High pass filter can be aligned, to produce the weighting response limits and to provide in the Contemporary Design practice preferred crest by response.High pass filter is regulated and is comprised that unit is the peak frequencies (W of Hz
H) and unit be dB amplitude (| A
H|).Hinted default Q
HBe provided with.
Motor (B L )The attribute of-magnet arrangement and voice coil loudspeaker voice coil is unified into the tradition expression.Voice coil diameter, winding length, gap magnetic flux, pole dimension etc. are the parts that produces the conventional loudspeakers model of motor and generator equivalent.Obtain reduced representation with the power of electric current and mechanical movement and back-EMF relation and other factors relevant with mechanical attributes.Sometimes comprise leakage inductance and mechanical quality relation.These elements are by various measurement devices, calculating or derivation, to produce one group of motor relevant parameter that can influence a plurality of aspect of performances of loud speaker.Customized parameter for bucking-out system and its processing depends on B
LTherefore, if desired, the model relation that can make is established, thus B
LChanging can the modulation parameter setting.For example, B
LSpecification can be used for following the tracks of or readjust other parameter of the similar loud speaker that is used to have different magnet weight, voice coil loudspeaker voice coil length or other dynamo-electric factor.Scalable B
LParameter can be: magnetic flux x length, voltage x speed, crest drift length, and resistance/inductance or time constant.
Bass resonance (W Q ) or self-resonance-this is the natural bass resonance frequency of loud speaker.Its value is suitable by volume of air, mechanic sound, swept area, damping, moving-mass, motor characteristic, and other design features of loud speaker determine.Do not resemble traditional bass model, the acoustics coupling factor is not W
0The part of response is because the L that it has been calculated in bucking-out system
XParameter has suffered.This layout prevents in the interaction of regulating between the parameter, and is transformed into the LCR resonator equivalence of mechanical behavior for the equivalence of mechanical behavior.Frequency W
0, Q
0With coupling energy or amplitude | A
0| the user command language can stipulate for the response of the conjugation of mechanical resonant behavior.Has the identical amount utmost point but opposite amplitude because be used for the loud speaker behavior of system with calibration response, so the group delay behavior can be very good.Adjusting is that unit is the W of Hz
0, as the Q of a number
0, and unit is dB | A
0|.These regulated values can be determined or determine by calculating with experiment method by very near scope equipment, position probing transducer.
Tuning (the W of port B )-many loudspeaker design become to provide a kind of extension frequency response or improve the second bass resonance of Power Processing planned.The physical structure of finishing this point comprises port, pipe, passive resonance device, labyrinth, other bass horn etc.Many documents have been devoted to these systems are carried out modeling and tuning, normally in order to realize the most smooth possible frequency response.Such model combines with bucking-out system, potential expansion bass, improves transient response, and improves efficient and do not increase the cost of loud speaker.Can and expand the bass ability from the structure more high-power processing of design, and can remove by using this tactful frequency response scrambling that generates and holding the band distortion to trade off by the conjugation correction.When carrying out this selection, port can be big and by tuning must be lower, housing can be less and other variations of improving bass.The generation result of thick response and time bass overload is put upside down by bucking-out system.Sign or switch can be the parts of control operation, and this control operation recognizer conditioned disjunction is at the responsive state at loud speaker place.Be identified for the on off state of this feedforward/feedback-type system from the limiting condition of sample or test.Then, from switch or state input, select the parameter coefficient.By this way, bucking-out system can be by means of fuzzy logic control or the operation of other method, to prevent unnecessary triggering (toggling) or the variation for parameter value.For example, different volume control setting, programmed level or bass content can change parameter coefficient and aligning, with the realization higher-wattage or than flat response optimization.Switching manipulation may be listened, but the control magnetic hysteresis provides more not obvious or tedious strategy change.Cheap equipment be plan, and may transship or be forced to surmount reasonable linear operation.Bucking-out system with suitable control logic operation can activate soft and loud mode of operation, and every kind of state has optimal alignment, and the distortion that does not produce between it is continuous.
Mechanical resonant (W 1 , W 2 , to W n )The mass part of-speaker system and action resemble movement the resonator.With W
0Like that, these great majority are unintentionally, and they add in the acoustics output of loud speaker usually.These also comprise dome, awl basin among other things, reach bending and the quality behavior and the cabinet resonance of surround.Equivalence LCR behavior be parameterized into no interactional specifying calibration or be used for W
0Those similar adjustings.It is that unit is the W of Hz that resonance is regulated
1, W
2, to W
nUnit is 1 Q
1, Q
2, to Q
n(describing below); And unit be+/-dB | A
1|, | A
2| extremely | A
n| (describing below).Seeming, little, the low Q resonance that is similar to room response usually has acoustic shock.Different with the test microphone that is used for conventional response smoothing, the audience can move everywhere, and in time sensing with know the signal attenuation of collapsing into wideband resonance.Conjugation is proofreaied and correct and is eliminated this difficulty, and helps to improve the result from the auxiliary equalizing system.
Stable state resonance (W CC1 , W CC2 To W CCn )-use the hiding compensation process of multi-resmator trapper and the enhancing of weighting side energy to place by frequency, and regulate by these Control Parameter.The sound result who reduces or remove self-dalay node resonance and standing wave to disturb.
Coupling and loss factor (| A| 0 , | A| 1 Extremely | A| n And Q 1 , Q 2 , to Q n )The Q parameter of-some frequency can be estimated as default value, these default values for the public material of loud speaker, design, and building material work.Owing to may or simple measure the interim Q of determining by the response line chart hardly, so fixed value is actual, and default value is selected the quantity simplifying and reduce to regulate.
Wave interference (Td)The phase of wave that the finite size of-loudspeaker housing can be created in behind the radiating surface closes interference pressure.Usually because the complexity of calibration response is ignored this problem.Expensive loud speaker disturbs to defeat echo with the big electric machine assembly structure with close magnetic coupling.These systems usually have layer, special back cavity or the transmission conduit that is shaped that internal partition, dissimilar absorbing material are made, so that help to remove interference.Typical speaker presents the constructive/destructive wave interference from its simple box housing, and these housings finally cause the response ripple that occurs increasing with the frequency increase.Owing to the short-circuited coil effect with from B
LDamping by than small magnet, go back raw steel and other economic factor reduces, so scrambling worsens.Correction is undertaken by the opposite response of conjugation that postpones the feedback loop process from.Although it is possible that simulation realizes, the DSP method is more economical, and according to its character, produces good equivalence for physical behavio(u)r and the problem that will solve.Similar correction can reduce the reflection interference from floor, table top, wall etc.
Tilt (dB)-most of audiences of the same generation like responding with increasing the loud speaker that frequency reduces a little.When making loud speaker cheap, its response often raises.Bucking-out system is proofreaied and correct owing to reducing many problems and the variation that magnet weight, improvement efficient and extended high frequency response take place.Yet, proofread and correct the smooth acoustic balance that produces by these conjugation and compare with contemporary tone standard and may sound muddy or weak.Tilt to produce a compensation response slope.Tilt parameters resembles operates the tone control, and is used for realizing the bass-high pitch balance of wishing.L
XAnd H
XInside handle and conventional response flattening method or process can produce this response.
Postpone or all-pass-this parameter is in time removed signal to compensate high and low-frequency transducer from the local radiation of difference.Adjusting can reduce group delay distortion, the phase matched of improvement and time bass horn, and aim at indicial response.Use physics or electric measurement to regulate.
Fig. 8 a to 8f represents the control panel demonstration and is used for regulating the menu of parameter.Response curve is expressed, reached in measurement data, design provides Useful Information to regulate or tuning system to loud speaker.System produces those the conjugation response for loud speaker, and removes quietly and postpone or long stable state mechanical sounds.For many positions of listening to, experience has shown with more complicated conventional smoothing way compares better performance.Realization for these functions can utilize the ordinary numbers process.Typical case's known digital process is represented in appendix A.Selectable known digital realizes being used for realizing the result of all fours.
Use analog circuit also can realize bucking-out system.Yet the part of multi-resmator or coupling function can not be followed the tracks of wide tuning range, unless they are complicated.So it is functional and show analog circuit with the similitude of the better DSP equivalent of knowing owing to it.These circuit have customized parameter control, but they require component variations with the intrinsic parameter alignment precision of analog digital system.Following example is tool half parameter regulation ability and produces the traditional circuit of the conjugation response those that resemble description.
Cut-off filter-Sallen and Key circuit can form active high pass and the low pass filter with the response of scalable crest.Fig. 9 represents to be configured to two filters of a single op amp.In band response be smooth, and cut-off slope be+and-the every octave of 18dB.L
PAnd H
PThe crest amplitude be adjustable, and corresponding with Fig. 4 b.Yet, must predetermined frequency for this circuit.For this example, two parts do not interact because its broadband separates.
The constant-slope equalizer-in active feedback circuit, change the RC time constant to resemble response curve Fig. 4 a with generation.The circuit that is illustrated among Figure 10 is the lifting half of ripening parameters tone control.For in that tiltedly limit is independent with the good parameter between intersecting, limit its adjustable range.
The parameter trapper-Figure 11 and 12 expressions have the simple analog notch filter circuit of wide tunable range.It is constant that notch depth keeps, but Q increases with frequency configuration.Can select components values to provide Q for the practical adjustments scope
0, Q
1To Q
nRationally approximate.
Weighting compensation trapper-one composite filter element is made up of one or more sharp-pointed trappers, and each trapper makes energy be added to the one or both sides of blanketing frequency (reject frequency).When its inhibition of careful selection and lifting energy and bandwidth, filter system can be removed undesirable energy, and very little to the compromise or change of phono-equalizer unit.The inhibition trapper that is used for this purpose is sharp-pointed, has high decay and generally is high Q's.Sideband compensates or recovers best by carrying out in the lifting response that suppresses the place, both sides.Yet array response is roll-offed and the loud speaker of interfering energy problem for having, and one-sided compensation role may be better.Asymmetric lifting helps the graduation frequency response.Others are identical.Compensation can be very little, has low Q, and when process is in or be not in the work, is that the average pink noise energy in half to one octave band at center is constant with the correction.
Decay from sound can move to low Q sideband frequency from sensuously.Therefore, for one-sided or single tuning method for improving, it is preferred being used for preferably the double tunning aligning that indicial response is stable immediately.The careful tuning composite filter that produces with convergent-divergent of energy is so that can carry out tuning to it quietly on useful frequency range.Do not having under the situation of weighting, influencing nasal sound in the little response loss of proofreading and correct either side.Dyeing may be delicate, but when using more timing, loss may surpass any advantage.If the equilibrium of the accurate way of image scale like that only makes response smooth, then especially really can this thing happens.Weighting is eliminated folding and is declined, and allows multiple correction more effective and do not have sound to interact, and when the school was applied to the loud speaker with different behavior properties unintentionally, weighting can also be eliminated loss.
Realize that for any neutral weighting response trapper can be made up of resonance and the antiresonance response added on the signal.With reference to Figure 13, correcting element may comprise single high Q trapper, in its frequency set on the behavior pattern.A low Q lifting response is placed on same frequency and sentences the equal weight energy that affords redress.The circuit part of Figure 13 is illustrated in the actual combination that active circuit trapper and passive LRC in the feedback path promote resonator.Two parts all produce weighting response trapper.Yet tuning range is limited, and low Q promotes and may listen, because the human auditory can differentiate the transient state sound that decays to low Q resonance.
Better choice example is to use two low Q resonance to promote response, and each is by tuning and be placed on the place, one or both sides of high Q trapper.Figure 14 represents the example be made up of four tunable biquadratic (bi-quad) resonators or state variable filter.Two of filter produce the high Q trapper that sealing separates, and other two the low Q energy that are raised that are provided at outside high side and downside place.These state variable filters produce with dsp processor easily, and they keep constant Q and notch depth on wide tunable range.The analogue system that produces the response of representing among Figure 15 has eight precision variable resistances that link on single shaft, with tuning W
CC1Or weighting trap parameter.Figure 13 represents to be used for a circuit of one of four parts.Figure 15 represents to be used for the response curve that two different Q are provided with, and these are relevant with among Fig. 4 d those.Can aim at double tunning promotes to produce very fast and less steady-state response for transient state.Resemble from the double tunning trapper the accompanying drawing confers similar advantages is provided, and dead band or band inhibition ability also are provided, to adapt to the manufacturing tolerance limit between the different loud speakers.Still need side frequency to promote, and preferably use the double tunning resonator.
When having like attribute, adjacent behavior pattern can carry out other variation and simplification, as possible for most of loud speakers.Two or more inhibition trappers can be shared Q and amplitude setting and compensation and promote.Combination comprises three trappers etc. that have two trappers, two trappers with twice asymmetric lifting that promote for three times, have twice.Can use the low Q of the list with two intermediate frequencies between the trapper to promote.Have following, following and between the low Q of three times of frequency to promote be a kind ofly to change preferably.For all these realizations, notch depth is usually bigger, and side frequency promotes less usually.Usually, make for about the identical or a little higher than situation that not have correction of the integral energy of the average random noise of compensatory zone response.
Postpone to disturb or all-pass-one hybrid modulus CCD equipment can produce less, tunable delay easily.Although performance may be relatively poor, they can resemble and connect the example among Figure 16 or dispose, so that the behavior of interference shape to be provided.This circuit can produce for from the reflection relevant with wavelength of the other parts of wall, desk and loudspeaker housing inside or transmission path or system and the approximate conjugation response of transport behavior.Circuit can be arranged to produce a paraphase comb filter or additivity and disturb the shape response, and this response is opposite with subtracting property interference loss from reflecting surface aspect time, phase place and amplitude.Correction is disturbing the impairment place to promote.This circuit also can be adjusted to has the response of comb filter shape, to offset the additivity energy from the reflection in the loudspeaker housing.Can form better time delay interference filter or the response of comb filter shape by the DSP process.It is relevant with the physics reflection model, and similar with the other parts of corrective system that simulation and DSP can both be configured to, and controlled by the parameter regulation relevant with physical behavio(u)r.Postpone the interference path filter and have the control that absorbs, reaches the interference correction amount that needs about size, surface.
With reference to Figure 16, Td is with directapath from the loud speaker to audience and also the difference between the long bounce-back path from the loud speaker to audience is relevant.Td also with loud speaker and housing in opposed surface between go out relevant with return path.The feature of the wall of loud speaker back also can be described in the same manner.Big Td provides big distance.RC is relevant with surface roughness or the absorption under high frequency.The RC product is big more, and response of upper frequencies comb filter and the loss of proofreading and correct are big more or decay fast more.The numerical value of control R1 governing response or correction.The CW direction increases the response of subtracting property, simultaneously near to op amp+the CCW position of input provides maximum additivity response.
This circuit produces the disturbance response that its amplitude reduces with frequency.The loss of this coupling or simulation actual loudspeaker absorbing material.Come many in the irregular response of loud speaker from childhood can be become certain easier thing of handling by bucking-out system that seems with experiment method.Usually, the delay that realizes this point is provided with coupling from the desired anti-arrival ripple relation of loudspeaker housing.When it mated really, such customized parameter equaled wide variety of conventional response smoothing process.
Figure 17 is an all-pass or phase shifts network.Its frequency response is smooth, however its output under high frequency homophase and under low frequency out-phase.Circuit changes transient response and does not change frequency response.Variable control increases transient frequency, because it is diverted CW.This element is useful for proofreading and correct group delay or other transient state relevant response.
As mentioned above, usually can listen by the mechanical disturbance that loud speaker produces, but be sightless or be difficult to explain for the response measurement that utilizes frequency scanning and microphone to carry out.Use the conventional compensation approach of dark trapper to cause nasal sound or harmful balance aberration usually.Weighting compensation notch filter of the present invention addresses this problem, and produces some other advantages.When two drivers (bass horn and loudspeaker) only intersected by a capacitor or by the circuit of overlapping frequency, one or two driver can have interference compensation and not for other sensation loss.Same situation is applicable to the different positions of listening to.Can compensation have position of bad response and compromisely be used for the sound that other listens to the position.Correction is hidden by weighting side energy.Because the good position of listening to can be compromise by proofreading and correct, so the listening to the position and can have the good sound characteristic of wide region.This feature is particularly useful for the horn loudspeaker that is used for arenas sound, and wherein different the installation needs slightly different correction.By using default optimization for a class loud speaker or structural feature, parameter control and adjusting are simple with intuitively.
Some most important behavior of loud speaker (but with respect to acoustics sensory effect) can not be by conventional method modeling or realization.Such behavior comprises to be disturbed and resonance is coupled and from the non-linear result of such behavior.In addition, need to consider with the rigidity of motion parts and be used for other relevant space factor of high-frequency decoupling away from the motion of driving voice coil loudspeaker voice coil.Any of these factor can both produce source movement, postpone that energy discharges and for the phase error of binaural.Usually, such destructiveness response may be sightless or be very difficult to explain for conventional microphone and spectrum analyzer calibration steps.
An example for the parameter addressing of specific physical effect compensation is for mechanically decoupled compensation in big gamut loud speaker.Such loud speaker is usually designed to and makes whole awl basin motion under low frequency.Under high frequency, the inside of having only driver is main active radiator.The remainder of awl basin is had a mind to decoupling zero with its node dispersion that decays.This design alternative changes the position of an equivalent radiation source.A kind of linearity correction that in time moves forward high frequency radiation uses mixed bandpass filter (complexpass filter) to postpone with the frequency band limits that produces lower frequency.Then, when frequency increased, hiding postponed to reduce, and kept the phase matched for the response order of loud speaker thus.Can remove some group delay distortions like this.Can produce the information of specifying from the physical size of loud speaker and the decay and the velocity of sound attribute of awl basin from the correction of special filter process.Yet, can determine that late effect and decoupling zero frequency are to produce parameter value with experiment method.If some of speaker portion are varying sized or attenuation attributes, the new value of then extrapolating.
An example that is difficult to maybe can not to use a kind of parameter addressing compensation of conventional method compensation is to the compensation of Doppler modulation in little loud speaker.Computer and multi-channel sound system need little loudspeaker plays to get very loud.Fast, the combination of high displacement awl basin motion generation can apply additivity or subtracting property speed to the sound that reproduces.The low frequency movement of speaker awl basin applies the Doppler mudulation effect by moving effective high frequency radiation zone.This effect is very annoying, and the typical sound of the little loud speaker of produce making great efforts will to play loudly.When radiation areas, frequency, and acoustic power export when known, can rationally calculate (see figure 5) accurately to motion of awl basin and the Doppler radiation factor that produces.Produce a kind of opposite alternately time delay in order to proofread and correct loudspeaker response.This long-pending property or non-linear process can make equivalent radiation source more stable, thereby reduce nonlinear distortion.A good behavior model and a single dimensional parameters of loud speaker can be specified correction.Any such open loop or forward direction gamma correction all are difficult to realize very much.It is far better when the time delay of modeling is modulated at it the conjugation response corrections is provided accurately.Here comprised example,, and will in time become actual from the instantaneous correction of DSP method because move by the model rational prediction from the awl basin of bass drivers.Intend postponing to experimentize by using by the CMOS pattern of voltage-controlled oscillator clock operation.The compensation of one paths is from the stand-by period of two " group bucket formula (bucket brigade) " equipment, and another reception V-CLK postpones modulation to produce.
For node bending, wave interference and nonlinear motion situation, removing or decaying of the behavior response by using weighting trap process is a kind of good compromise.Weighting compensation energy movement parameter is to the place that needs it.If desired, then can modulate its seriousness, with matcher dynamic characteristic best, from the distortion of loud speaker, and the human scf frequency band sense of hearing.
When the dynamic characteristic of sound signal was detected and is used for changing parameter or hides compensation, extra bass fan-out capability and response expansion may be relatively poor.Any speaker system work that this technology can be served as reasons and be improved one's methods and operate.
Yet if the partial design of loud speaker is become to require dynamic compensation, extra performance characteristic is possible.The adjusting tabulation or the bitmap that are intended for use particular system can have parameter identical with general-purpose system and adjusting, i.e. control has common feature.Thereby the electronic system that has bucking-out system can receive instruction, with compensation with optimize multiple loud speaker model and the product to append on it, described multiple loud speaker model and product had both comprised general purpose speaker, with comprise aim at bucking-out system use and design those.When needs, system can improve definition, imaging, and bass extension and do not change phono-equalizer unit, promptly keeps the voice print note of production line.
The adjusting effect of parameter generating is by the symbol or abbreviation description or the expression that are included in the above table.By this way, the unified tabulation of mathematics proposition, circuit, loudspeaker design feature and other language-specific to programmer or the visual interpretation of user's energy.Then, response curve, behavioural characteristic, wavelength relationship and feel other important thing for the mankind become relevant with the process model of design that is used for speaker system and/or compensation.Simplify compensation, because the interaction between design and performance change and fundamental relation is significant and intuitively.
Stable state and node compensating parameter regulate comprise unit be Hz frequency, as the Q of a numeral, and unit be the inhibition of dB.Because multistage nodes ' behavior is possible,, Q and inhibition more may have similar value for compensating frequency more than one so regulating.Can link control, thereby being two or more frequencies of Hz, unit can specify correction for the nodes ' behavior of jointly shared machinery or interference properties.
The bell pattern compensation that is used for the speaker awl basin provides a good example.Several method can be determined these frequencies.Use sine-wave excitation and optical interference measurement can observe multinode or the interference of phase of wave pass.Can explain waterfall figure, to disclose self-dispersed stable state energy from stimulation of the MLSSA type shown in Fig. 7 or difference microphone probe.These behaviors can be listened, and can manually or lentamente scan hiding compensation process on frequency, change with the sound that is disclosed in the pink noise reproduction period.Experimental technique needs careful and experience, because room reverberation can be simulated mechanical sounds.Relevant between three kinds of technology is good, and when several frequency of determining from similar reason, similar Q and share the synthetic weighting trapper that promotes parameter and simplify and proofread and correct.
Above parameter and its are regulated the configuration compensation that changes the specific behavior that is used for loud speaker.Some processes are restricted to a narrow frequency range inherently, and wherein the behavior most probable of particular types takes place from speaker system.Other process of influence time and response slope covers a wide spectrum.These dedicated operations are enough isolated each other, thereby the interaction between them is less.Can change the parameter of choosing and not influence other parameter.In addition, data demand is appropriate for useful adjusting resolution.
As with as described in the upper speaker example, the control of regulating bucking-out system is relevant with the physical piece and the acoustic properties of loud speaker.Can improve in the same manner and have similar but be not other loud speaker of duplicate design or structure.Control or the specification information of finishing this point have identical language simply and intuitively.A less and cheap loud speaker can significantly improve by means of 16 parameter regulation and several default setting.In order to mate the Complex Response from this system, traditional multiband or graphic equalizer need surpass 100 frequency bands and much more control information far away.
Bucking-out system is used slope, intersection and other mathematical function to produce for the expectation of loudspeaker performance and is proofreaied and correct.These operations are by coefficient or point and by procedure command control, rather than by proof and calculated response for linear line chart.Because each process has a special properties, so frequency range, amplitude, Q etc. are restricted to parameter area the smaller portions in a control space.One three word code can produce a resonator of accurately placing or the response trapper subsystem of complicated weighting.Under the situation of 8 code words, this figure or information sequence provide 128 points that are used for tens of frequencys multiplication, be used for amplitude with 1/2dB be step-length+/-20dB, and 16 Q spaces of being provided with and being used for procedure command and control formatization.For this example, 384 points in sonic-frequency band or frequency can be used for being provided with sharp-pointed inhibition trapper and weighting compensation.The bitmap that is used for other parameter control and procedure command may require small in resolution, thereby provides even bigger economy.This compact specification feature can be used to proofread and correct the bar code of the bucking-out system of particular speaker design installs, or is used for coming the dynamic control of the process of the code of hiding in the comfortable data flow such as being used in the HDCD system.As described in detail later like that, when the range of information that reduces to handle, the portable equipment such as hearing aids and communication system is benefited.
For multiple use, for comprising ten basic operations, promptly tiltedly the successful process of limit, trapper, compensation, cut-off filter, delay etc. can be chosen in 384 points or frequency in the sonic-frequency band.The process scale very rapidly increases with resolution: to suppress trapper may be sharp-pointed and it is accurately tuning to need, and interference compensation is complicated inherently, and handles a useful information that only discloses seldom from the loudspeaker response that traditional measurement is realized to simplifying.If do not become Compensation System Design identification and processing from the subsystem of curve or the response of modeling, just must on the pointwise basis, proofread and correct.Even the good response corrections of finishing by this way also requires sizable process power.When consideration time, phase place and stable problem, processed conventionally range widens.For this situation, the filter that Anywhere the useful calibration response of resolution in 3 d grid (as waterfall figure) needs or the quantity of process may be unpractiaca.When filter or processing power were assigned to that part of grid of have relatively high expectations resolution and more corrective action, some economy were possible.Even these effort also fail to realize the correction benefit of hiding or compensating of bucking-out system.
A good example of this difficulty is apparent from Fig. 6.Bucking-out system has 8 trappers, is used for a weighting trapper of node correction, reaches low frequency lifting intersection and oblique limit.The high frequency reduction offers loudspeaker to intersection.Obviously, it is conspicuous drawing a little and produce the synthetic difficulty of response.Bucking-out system is regulated (L by 24 times
X, L
S, L
P, W
0, Q
0, | A|
0, W
1To W
7, | A|
1Extremely | A|
7, W
CC1, and a default Q be provided with) produce this conjugate curves.
Remove similar strategy with signal in the compensating band and can be used for the highest and low-limit frequency.For example, by being reduced to the input of loud speaker, by just so not horrible from the kinetic distortion possibility of the excessive awl basin of bass energy.A kind of method that realizes this point is that LF-response is restricted to an actual value.Very possible is, loud speaker can carry out by following weak low-frequency sound reproducing, and condition is that program material can not sheltered lower bass signal.The wide dynamic range program material can force loud speaker to produce under these frequencies can feel output.Unfortunately, the weak output that is produced is often covered by other sound in the same perceived frequency band of people's sense of hearing.So the time is useless from the extended response of loud speaker mostly, and only adds distortion and consume booster output.
The weighting response corrections of bucking-out system can be applied to low or high-frequency wideband or by suppressing or listened to the side of filter.If careful this weighting response corrections of carrying out, then sensory response seems and to change, and can make expanded sound as it before filtering.Plan to reproduce high-power, inferior listen or the big system of inferior acoustic energy needs a kind of diverse ways, although identical method is suitable for.
Bucking-out system produces the zero-phase filtering device that its acoustics output has low group delay distortion to a loud speaker model and conjugation process combination.For this purposes, crest responds not only adherence to standard way, and is used in the aligning helping improving group delay, and becomes the part that allows the hiding compensation that the frequency band limits feature is opened or closed.
When selecting as described above neutral, can make bucking-out system change it by the degree of depth and compensation energy with minimum audibility.This feature allows bucking-out system to be followed the tracks of or modulated the procedure condition of control setting, power stage or competition sensation frequency band by the variation of volume.By this way, before distortion was inserted, bandwidth constraints can force more power to loud speaker.Since rationing now can listen energy, so less amplifier can produce identical playback volume.
These factors have Economic Importance.Loud speaker has the part of such design, thereby system can be benefited from bucking-out system.They have than the awl basin of minor circle and lower weight exports to produce higher acoustical from amplifier.Efficient is higher, but mechanical behavior is usually by compromise, and often raises with frequency from a kind of like this acoustics output of design.Do not proofread and correct, loud speaker sounds perverse ear and sharp, and therefore must compensation.Yet, in case changing by bucking-out system, these proofread and correct, loud speaker is just play loudlyer, and can be littler, and can use more lower powered amplifier.
If select virtual bass extension, then the strategy by means of careful formulation responds at moving crest of frequency upper shift or compensation.Becoming in the process setting at band edge place and relevant acoustics peak frequencies, the power of the bass content that depends on program material, amplifier is preserved, and the locomitivity of loud speaker.Level is higher when resetting, and low frequency energy is when strong, and the crest response moves upward on frequency, to keep reasonably boring basin motion and distortion performance.
The feature that most of entertainment systems have equalizer, tone control, reach other user's operation or start.Need the acoustics observability.Best and these cascade operations of bucking-out system, and can improve its performance.In case the betterization radiation behavior that is provided by bucking-out system is provided speaker system, various response levelling systems just needn't classify or infer from which part of the measurement response of microphone taking-up to be come from loud speaker or comes from indoor.Bucking-out system can be more effectively from damaging phase response or being unsuitable for eliminating unsuitable equilibrium these response smoothing programs of other audience position.Cascade operation also guarantees to remove the distractive mechanical sounds that is caused by the unrecognizable response of conventional method.Human binaural is good at sensation, identification, is reached these sound of localization.In case remove them, traditional equalization methods just can promote high frequency, and does not have jangle, and promotes low frequency, and does not have peculiar box rumble of minimal construction or muddy sound.
For bucking-out system, the specialized simulation function block circuit can form simple utility system.The response range that is used for its variable partition can be estimated by the conjugation model, thereby parallel signal path and a plurality of sharing functionality are possible.The active equipment that needs much less in individual paths reduces cost and distortion thus.The relevant correction of some times can be undertaken by all-pass filter, and other delay operation is unpractiaca.
The exemplary simulation of the bucking-out system in the loud speaker context and DSP realize being provided at respectively among appendix B and the C.Being described below of other purposes of bucking-out system.
Communication system-communication system may stand unnecessary narrow-band noise or the tone under fixing or change frequency.Very frequent is that some stand-by period are available, to allow subsystem identification and to follow the tracks of such tone.When produce out-of-phase signal with remove interference unactual or can not the time, bucking-out system realizes a kind of effective result.Usually, can follow the tracks of interference with the removable weighting response of parameter trapper.Have and the identical frequency that is subjected to blanketing frequency if not information signal, then proofreading and correct will be effectively and not to reduce or change sound.Usually, communication system has transducer, as microphone, earphone and the loud speaker as the sound reproduction system part.These elements can have can be individually or as the unnecessary response of collective of system compensation.One or more processors can be placed on any place in the signal chains.Their energy Be Controlled or programming are to compensate many components mixtures, as transducer, signal path, people's sense of hearing requirement etc.In order to set up a kind of like this system, Control Parameter information can or be estimated by the identification of the covered code in signal path.Accessory channel and other devices can be used for transmitting this information.Because bucking-out system uses this information to produce very complicated response, so trimming process can be installed in a plurality of systems effectively.Example comprises computer speaker, is used for hearing impaired's telephone system, reaches mobile communication.For these systems, processor is user's utensil outside or be not its part endways.So bucking-out system can be programmed to a kind of concrete model of utensil, and by outside activation.Processor part or all of can with utensil together or not with its together.
Hearing aids-many hard of hearing result from the damage to fine hair cell in the auditory nerve.Usually people are subjected to the evil of tinnitus or tinnitus (head ringing), and understand dialogue and have any problem in crowded noisy room.Sometimes with the approaching cell mass in corresponding interval of narrow-band mechanical damage has been arranged, caused the excessive neural response that high strength is stimulated.This effect usually sounds is discord and pain.It may cause and go to and from the interruption in the audio feedback path of brain, thereby starts too early defencive function, increases the weight of unhappy sensation thus.Because the stimulation that causes mechanical movement is by the medical science test routines easily in the frequency range of definition, thus can be easily the parameter weighting notch filter be tuned to same frequency, to block the transfer voice that stimulates these cells.If suitably set up the additivity weighting, then reduce sensation loss for other sound for the individual.In typical case a kind of, trapper must have the frequency band suppression characteristic that possibility must broaden with the acoustic pressure rank.Compensation side energy is followed the tracks of these and is changed to reduce the intelligibility loss for other sound.The system that is designed to carry out this correction can be more effective, and its dedicated processes may the few power of battery of absorptance generic response formative method.
Watermark identification-a kind of the record can form by means of the given frequency of being removed by a sharp-pointed trapper.If identical recordings is identified after needing, then can make system search the known frequency of losing.People can expect vibration, noise, and uncertain clock rate move dead frequency band and produce multiple difficulty.Record can use the sequential of music signal defining operation frequency and the safe trapper of coding.Reduce the clock dependence, and use figure key to prevent that someone from finding these frequencies and changing purpose.At playback duration, the key identification division of program starts the decoding parameter that is used to confirm.As above-mentioned communication system, the trapper that is write down should be as well as possible ground quiet or hide, and may jump to another from a frequency.Parameter control weighting compensation method is desirable for this application, and keys in frequency agility and a kind of effective and safe of being combined as of hiding system provides.
Eliminate feedback from audio system-obtain when relating to sound and reproduce strengthen facility, phone and other system than loud noise and stand feedback.Usually, a microphone picks up certain part of reproducing acoustic signal, and adds on the signal to cause vibration.Can the classify phase relation of room echo and cross-talk of the ripe DSP part of speaker-phone is so that transfer voice is clear and eliminate feedback.Frequency shifter randomization feedback phase is to prevent to howl or the slow foundation of high Q loose couplings vibration.Sometimes, from the interference level performance or synchronously of hiding of these methods.Can tunable weighting trapper be set to sensitive frequency with oscillation-damped not for the remarkable loss of sound.Double tunning or multiple-tuned version do not have anything to interact each other, and intrinsic dead band make tuning go out to feed back much easier.
CD-audio player-a kind of exemplary electronic system with numeral or analog domain (or both) operation can make up intentionally, and the user regulates and bucking-out system.Part description, Mathematical Modeling, measurement data, and human preference information can be combined, and incorporate in its design.In case defined parameters, and determine its coefficient value, an organized primary block just can carry out the specific correction response with difformity and size for loud speaker to electric or mathematic system programming.Parameter list and even the specifying calibration model can be downloaded to a digital signal processor in CD-audio player or the miscellaneous equipment.This operation can be carried out at any time, thereby it provides upgrading able to programme.It can be activated by bar code, Long-distance Control, from downloaded, or is installed to special player/set of speakers and closes.
Although shown and described several concrete form of the present invention, obviously, can carry out various modifications and do not break away from the spirit and scope of the present invention.
Appendix A
Figure A1, A2 and A3 represent to be used for low pass filter (L
P) and high pass filter (H
P) may the realizing of cut-off filter.The progression of these concrete filters keeps lessly to support low MIPS to realize.Figure A4 represents to be used for high and low tiltedly may realizing of limit equalizer.These equalizers are used for L
SAnd H
SThe equalization parameter device that figure A5 represents to can be used for to promote or trapper is used is realized.The combination of such equalizer can in conjunction with, as shown in figure A6 and A7, to set up the trapper effect of compensation.
Figure A1
Figure A2
Figure A3
Fig. 4 A
Fig. 4 A
Fig. 5 A
Fig. 5 A
Figure A6
Figure A7
Appendix B
Figure B1 is the block diagram that is used for compensating the bucking-out system of a small shelf loud speaker that has 5 inches bass drivers and 3 inches loudspeakers.The feature of loud speaker is as follows:
Bass horn: dome=4.33k (trapper that has LC)
Awl basin=4.9k (trapper that is compensated is only arranged)
Edge=the 2.8k (active trap) of awl basin
Loudspeaker: dome=15.1k (not compensation)
Awl basin cr=11.6k (active trap)
Awl basin cr=9.32k/9.45k (damping is compound)
W
0=1.38k (LCR trapper)
14 kinds of adjustings are provided.Figure B2 represents to be used for producing L
X, H
X, L
S, H
S, L
P, and H
PThe circuit of filter and parameter regulation.Add lower frequency by crest, to produce the response characteristic of 8 inches bookshelf systems.For this circuit, Q and crest amplitude are by the assembly setting of square frame mark.Figure B3 and B4 represent W
0Trapper part and be used for the representative tuning of loud speaker.With dB is the W of unit
0... and | A| is adjustable, and a resistor is provided with Q.Two groups in these are carried out four kinds of adjustings.Figure B5 represents that the low Q of a list promotes.The adjusting that is used to promote with frequency is partly provided by op amp.Figure B6 is the all-pass equalizer that is used for time adjustment.The all-pass sets of equalizers is incompatible from six outputs that the source procedure circuit is arranged.
Appendix C
Use the DSP compensator of the firm and hard existing computer regulated of a Standard PC and Motorola EVM56362 DSP valuation.Source code and application note are as follows.
The tuning application program note of loud speaker
The tuning application program of loud speaker is write as 32 application programs of Windows OS (please refer to the document of the MFC that comprises with Microsoft Visual C++ development environment) with OO MFC application framework.This application program has a dialog interface.Main conversational class, CTabDialog is a subclass of MFC CDialog class.The CTabDialog class realizes " label type " dialog interface.Each label in the dialogue is the subclass of MFC CPropertypage class.Each label is represented the different aspect of loud speaker correcting algorithm.Following is the tabulation of labels class:
● CMainpage, among other things, the UI that controls with the back volume before also realizing being used for
● CShelvpage, realize being used for the UI control of low and high tiltedly limit equalization filter
● CCutoffpage, realize being used for the UI control of low and high crest cut-off filter
● CNotchpage1 and CNotchpage2, realize being used for the UI control resonance of limiting loudspeaker (for example for) of a plurality of notch filters
● CStWaveRijecetpage, realize being used for the UI control of one group of filter of standing wave that can the limiting loudspeaker case
● CDBNotch, realize being used for the UI control of double tunning notch filter
● CAllpasspage, realization is used for the UI of second order all-pass filter
Each customized parameter on each Shipping Options Page is by a case representation of CSlider class.Each UI slider has the scope of 4096 discrete values.When the user handled the UI slider, a piece of news was delivered to the example of CDSP56Manager class from Shipping Options Page.In such, suitable calculating takes place linear input value is transformed into calculating the essential one or more values of transfer function of expression to be set by the user.Use that I2C is connected in series to be transferred to DSP to these calculated values.DSP carries out for the essential calculating of the real-time implementation of above-mentioned transfer function.DSP can calculate a series of filters in real time and calculate, to allow to realize total cascade transfer function of all loud speaker correcting filters.DSP can receive analog or digital input data, and the analog or digital dateout of transmission process.