US3719905A - Reverberation device - Google Patents

Reverberation device Download PDF

Info

Publication number
US3719905A
US3719905A US00137840A US3719905DA US3719905A US 3719905 A US3719905 A US 3719905A US 00137840 A US00137840 A US 00137840A US 3719905D A US3719905D A US 3719905DA US 3719905 A US3719905 A US 3719905A
Authority
US
United States
Prior art keywords
foil
reverberating
reverberation
box
metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00137840A
Other languages
English (en)
Inventor
W Kuhl
J Wieking
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BARCO-EMT GmbH
Original Assignee
ELEKTROMERSTECHNIK FRANZ W KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ELEKTROMERSTECHNIK FRANZ W KG filed Critical ELEKTROMERSTECHNIK FRANZ W KG
Application granted granted Critical
Publication of US3719905A publication Critical patent/US3719905A/en
Assigned to EMT-FRANZ GMBH reassignment EMT-FRANZ GMBH CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: ELEKTROMERSTECHNIK WILHELM FRANZ KG
Assigned to BARCO-EMT GMBH reassignment BARCO-EMT GMBH CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE DATE 1/25/89 GERMANY Assignors: EMT-FRANE GMBH
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K15/00—Acoustics not otherwise provided for
    • G10K15/08—Arrangements for producing a reverberation or echo sound
    • G10K15/10—Arrangements for producing a reverberation or echo sound using time-delay networks comprising electromechanical or electro-acoustic devices
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/0005—Separation of the coating from the substrate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S84/00—Music
    • Y10S84/26—Reverberation

Definitions

  • ABSTRACT A reverberation device including a frame having a reverberating metal foil of very small thickness.
  • metal foil comprises a nearly pure metal having the characteristics of high thermal conductivity (A) :69 W/m, a low coefficient of thermal expansion (01) 19.0X10- a low sound ye1oc ity c E/p) sITbHi/E vvherein the square of the coef fi cien tjf thermal expansion (01) of the foil, when multiplied by the square of the velocity of sound c and divided by the thermal conductivity (it) is less than 1.3
  • Known reverberation devices comprise a steel plate 1% mm thick and l 'k-Z m in area as the reverberating body.
  • the size and the weight of the device are cumbersome. If one wishes to reduce its dimensions, then thickness must be reduced to the same extent as area. Sound improvement of reverberation even requires reducing the plate thickness more than the area.
  • the plates damping factors may so increase that it is impossible to achieve therequired reverberation times of 4-5 seconds at low and middle frequencies and of at least 0.8 seconds for a frequency of 10 kHz with respect to mechanical recordings;
  • the square of the thermal expansion coefficient alpha of the foil material or materials multiplied by the square of sound velocity c and divided by the heat conductivity lambda must be less than 1.3 X mldegsec. watt.
  • Metals meeting these conditions are gold, silver, copper, platinum, chromium, molybdenum and tungsten, particularly the first four.
  • the foils according to the invention were made 0.008 -0.035 mm thick, preferably 0.01-0.03mm depending on the metal. Optimum thickness is 0.02 mm.
  • Such thin foils are appreciably more sensitive to acoustic interferences, particularly as transmitted through air and solids, than are the known reverberation plates of 0.5 mm thickness.
  • a two-shell housing is used in this invention. Since the required airtransmitted sound insulation is'practically independent of frequency, or very nearly so, and therefore must be considerable even at low frequencies, one of the two housings is curved'in three dimensions and very stiff shells are formed.
  • the second housing may consist of thin, flat or curved sheet-metal since its transmission loss need only be largefor middle frequencies at which the first housingresonates and therefore has less of a transmission loss.
  • the required and very large solid transmitted sound insulation is achieved by first, isolating the foil from its supporting frame,
  • Parts of the air volume of the inner and outer boxes are filled with sound absorbing material with open pores, preferably mineral fiber plates, foam rubber or foam plastic.
  • This porous material may not be mounted close to the plate itself, inside the inner box, so as not to unduly increase the plates damping. Parts of the porous material simultaneously may serve as the frame spring-support.
  • the reverberation time for thick reverberation plates may be changed in known manner by nearing or removing porous layers of large areas. For middle and small values of reverberation the time of reverberation is fairly frequency-independent. For thin reverberation foils therefore the low frequency reverberation time would be much less than for middle frequencies.
  • the porous layer consisting of several small parts in one plane which differ with respect-to their sizes and spacings from one another.
  • the porous layer may also be divided by means of numerous perforations of equal or varying sizes into several mechanically interconnected partial areas.
  • FIG. 1 shows a view of the echo plate without a box.
  • FIG. 2 shows a section through the plate and a double-walled housing.
  • FIGS. 3 and 4 show embodiments of the weight.
  • FIGS. 5 and 6 show embodiments of the damping or reduction plates.
  • FIGS. 7, 8, and 9 show embodiments and variations 7 of the echo time owing to the use of eddy current rigidly with the remaining parts.
  • the number of con- I nection points depends how the foil has been produced, how flat it must be in order to avoid audible oscillation distortions and how strong the tension force is to be for reducing foil damping or reduction.
  • the foil can be tensioned at the comers by one respective spring in a diagonal direction.
  • the oscillation excitation and sensing is carried out in the embodiment shown electrodynamically at two points with the help of very light oscillating coils 7 connected rigidly with the foil.
  • the associated permanent magnets, in whose air gaps the coils are located, are not shown for purposes of simplification.
  • one oscillating coil would suffice for exciting and sensing.
  • at least two sensing oscillating coils must be provided.
  • Two exciting oscillating coils instead of only one are then in this case acoustically more advantageous.
  • the number of the oscillating coils for sensing is increased.
  • the coils are arranged at a distance from each other and from the edges. Their positions can in other respects be chosen freely.
  • the echo time is increased by the distance of the porous plate 8, provided in this case with slots or holes, of the oscillating foil (plate) is changed by hand or by means of a remote control system.
  • the inner box 9 consists of two curved metal shells,
  • the outer box 10 in the embodiment shown consists of flat plates, which are produced using any suitable material.
  • the partial filling of the air spaces in the two boxes with porous sound absorbing material is not shown in order not to impair understanding of the drawing.
  • the frame 2 is connected with the inner box 9 by means of springs 11.
  • the box 9 is connected with the outer box 10 by means of springs 12. Between the outer box 10 and the supporting ground there are springs 13.
  • FIGS. 3 and 4 show a view of two embodiments of the weights 3 which consist of round discs 14 and 15 pressed together by means of a screw 16. Each disc has two pins 17, between which the foil 1 is clamped. An additional connection by means of putty with low damping properties may be convenient.
  • the spring ring 4 in FIG. 3 is placed around the pins 17 and led through the second spring ring 5. An additional point-like rigid fixation of the spring rings on all points of connection can also be convenient in this case.
  • FIG. 4 shows the U- shaped wire spring 18 which is connected rigidly with the pins 17 and with the holding part 6. A displacement of the holding part 6 before it is screwed into position can be used to set the desired tension.
  • the damping plate in FIG. 5 consists as an example of alarge quantity of parallel strips 19 of porous material with open pores.
  • the breadth of the strips is variable, and also that of the intermediate spaces 20.
  • FIG. 6 shows a further embodiment.
  • the porous plate 21 has regular or unregularly arranged large openings 22 and small openings 23.
  • FIGS. 7 to 9 show embodiments of variations of the echo time with the help of eddy current damping.
  • FIG. 7 shows a few permanent magnets 24 with rectangular or circular cross-section placed on both sides of the foil 1.
  • the polarity of the magnets placed opposite to one another is the same and those of adjacent magnets is different.
  • the eddy current damping of the foil is achieved by displacing the distance of all magnets from the foil.
  • FIG. 8 shows a pot magnet 25 whose leak flux partially flows through the foil 1.
  • FIG. 9 shows several electromagnets 26 with exciting spools 27 on one side of the foil 1.
  • the magnetic field and thus the damping is varied by the variation of the distance and/or of the exciting DC.
  • a reverberation device according to claim 1, wherein the metal foil thickness is within the range of 0.01-0.03 mm.
  • a reverberation device wherein the foil metal make-up is at least 80% pure of the material selected from the group consisting of gold, silver, copper, platinum, chromium, molybdenum or tungsten.
  • a reverberation device wherein the reverberating foil is mounted inside a first box closed on all sides and wherein this box is made of material with a large modulus of elasticity, and comprises at least two partial shells that are bent in three dimensions.
  • a reverberation device wherein a second outer box is provided for increasing the transmission loss and which integrates the inner box comprising at least two shells.
  • a reverberation device wherein the metal foil, the frame used for stretching the metal foil, the first box and the second box and the foundation all are oscillation isolated from each other by damped springs.
  • a reverberating device according to claim 5, wherein the inner and outer boxes are partly filled with an open-pore sound absorbing material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Multimedia (AREA)
  • Acoustics & Sound (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Building Environments (AREA)
  • Laminated Bodies (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
US00137840A 1970-04-29 1971-04-27 Reverberation device Expired - Lifetime US3719905A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19702020897 DE2020897A1 (de) 1970-04-29 1970-04-29 Verfahren zur Herstellung ungedaempfter Metallfolien

Publications (1)

Publication Number Publication Date
US3719905A true US3719905A (en) 1973-03-06

Family

ID=5769720

Family Applications (1)

Application Number Title Priority Date Filing Date
US00137840A Expired - Lifetime US3719905A (en) 1970-04-29 1971-04-27 Reverberation device

Country Status (4)

Country Link
US (1) US3719905A (de)
AT (1) AT314221B (de)
DE (1) DE2020897A1 (de)
GB (1) GB1327654A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070263307A1 (en) * 2006-05-11 2007-11-15 Young Optics Inc. Light integration rod module and optical engine
US8837745B2 (en) 2011-07-13 2014-09-16 Ecolivegreen Corp. Electro-acoustic audio reverberation device and method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1045117B (de) * 1956-04-20 1958-11-27 Grammophon Ges Mit Beschraenkt Anordnung zur Erzeugung von kuenstlichem Nachhall auf elektromechanischem Wege
DE1073215B (de) * 1960-01-14 Deutsche Grammophon Gesellschaft mit beschrankter Haftung Hamburg Anordnung zur elektroakusti sehen Nachhallerzeugung
US2923369A (en) * 1955-08-11 1960-02-02 Wilhelm Franz K G Acoustic reverberation arrangements
DE1472007A1 (de) * 1965-09-04 1968-11-14 Inst Rundfunktechnik Gmbh Nachhallplatte und Verfahren zu ihrer Herstellung

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1073215B (de) * 1960-01-14 Deutsche Grammophon Gesellschaft mit beschrankter Haftung Hamburg Anordnung zur elektroakusti sehen Nachhallerzeugung
US2923369A (en) * 1955-08-11 1960-02-02 Wilhelm Franz K G Acoustic reverberation arrangements
DE1045117B (de) * 1956-04-20 1958-11-27 Grammophon Ges Mit Beschraenkt Anordnung zur Erzeugung von kuenstlichem Nachhall auf elektromechanischem Wege
DE1472007A1 (de) * 1965-09-04 1968-11-14 Inst Rundfunktechnik Gmbh Nachhallplatte und Verfahren zu ihrer Herstellung

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Reference Data for Radio Engineers Fifth Edition H. W. Sams & Co. 1969, two pages: Title page and 4 45. *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070263307A1 (en) * 2006-05-11 2007-11-15 Young Optics Inc. Light integration rod module and optical engine
US8837745B2 (en) 2011-07-13 2014-09-16 Ecolivegreen Corp. Electro-acoustic audio reverberation device and method
US9396720B2 (en) 2011-07-13 2016-07-19 Ecolivegreen Corp. Electro-acoustic audio reverberation device

Also Published As

Publication number Publication date
DE2020897B2 (de) 1978-07-06
GB1327654A (en) 1973-08-22
AT314221B (de) 1974-03-25
DE2020897A1 (de) 1972-01-13
DE2020897C3 (de) 1979-03-15

Similar Documents

Publication Publication Date Title
US3829623A (en) Planar voice coil loudspeaker
US3636278A (en) Acoustic transducer with a diaphragm forming a plurality of adjacent narrow air spaces open only at one side with the open sides of adjacent air spaces alternatingly facing in opposite directions
CN1547416B (zh) 扬声装置及内部安装了扬声装置的电子设备
US3651283A (en) Loudspeaker having elongated rectangular moving coil
US4101736A (en) Device for increasing the compliance of a speaker enclosure
EP0400048B1 (de) Audiotransducer mit regelbarem flexibilitätsdiaphragma
US3892927A (en) Full range electrostatic loudspeaker for audio frequencies
US3008013A (en) Electrostatic loudspeakers
US3867996A (en) Speaker enclosure
CA1282162C (en) Electroacoustic device with broad frequency range directional response
KR880004716A (ko) 전기 역학적 확성기
EP0200257B1 (de) Elektrodynamischer Wandler vom orthodynamischen oder Bändchentyp
US7940952B2 (en) Electro-acoustic transducer
JPH024559Y2 (de)
EP0614600A1 (de) Lautsprecher.
US3719905A (en) Reverberation device
EP0118159B1 (de) Übertrager vom Bändchentyp mit einem mehrlagigen Diaphragma
US3236958A (en) Loudspeaker system
US3198890A (en) High fidelity sound reproducer
US2923369A (en) Acoustic reverberation arrangements
US1801521A (en) Loud-speaker horn
US1885308A (en) Loud speaker
RU2246802C2 (ru) Громкоговоритель
US4027111A (en) Ribbon loudspeaker
US4323737A (en) Driver unit for planar diaphragm type loudspeaker

Legal Events

Date Code Title Description
AS Assignment

Owner name: EMT-FRANZ GMBH,STATELESS

Free format text: CHANGE OF NAME;ASSIGNOR:ELEKTROMERSTECHNIK WILHELM FRANZ KG;REEL/FRAME:004837/0568

Effective date: 19880208

Owner name: EMT-FRANZ GMBH

Free format text: CHANGE OF NAME;ASSIGNOR:ELEKTROMERSTECHNIK WILHELM FRANZ KG;REEL/FRAME:004837/0568

Effective date: 19880208

AS Assignment

Owner name: BARCO-EMT GMBH

Free format text: CHANGE OF NAME;ASSIGNOR:EMT-FRANE GMBH;REEL/FRAME:005219/0604

Effective date: 19890126