MXPA99002299A - High-fidelity electrical circuit for media frequency reproductor horns - Google Patents

Abstract

The present invention relates to a high-fidelity electric circuit for mid-frequency reproductive horns comprising a high-pass filter with a cut-off frequency of 160 hertz, with 12 decibels / octave of attenuation, which functions as a voltage regulator; and a low-pass filter with a cut-off frequency of between 1000 and 3000 hertz, with 6 decibels / octave of attenuation, where the combination of both filters is useful both for protection against rupture of the cone and for operation at high powers, allowing in this way to reproduce the sounds without distortion

Description

HIGH-FIDELITY ELECTRICAL CIRCUIT FOR MEDIUM FREQUENCY REPRODUCTOR HORNS.

FIELD OF THE INVENTION The present invention relates to a technique of reproducing sounds without any distortion for use in horns, and particularly a high-fidelity electrical circuit that acts as a voltage regulator for use in 3 V horns. to 6 inches in diameter, being useful both for protection against rupture of the cone and for operation at high powers, allowing in this way to reproduce the sounds without any distortion.

BACKGROUND OF THE INVENTION.

It is now known that all sound reproducers from 3 Vz to 6 inches (8.89 cm to 15.24 cm) in diameter are connected to conventional electrical bandpass filters. However, the design of conventional bandpass filters operate within a range of frequencies between approximately 500 and 3000 hertz, depending on the frequency response of the selected horn to connect to the filter. This necessarily implies that frequencies lower and higher than said frequency range, that is, lower than 500 hertz and higher than 3000 hertz, will be attenuated according to the number of decibels / octave chosen for the filter design. Generally, bandpass filters are typically used on all media player speakers. All these typical filters show the serial and parallel connections that serve to achieve the same, that is, allow a certain frequency band to pass freely to the breeding horn. The band commonly used by said bandpass filters is between 500 and 1000 hertz to 3000 and 4000 hertz, in all designs available in the state of the art. However, the traditional design of the bandpass filters of the media player horn loses a very important part of the audible spectrum, that is, all the frequencies between 20 and 500 hertz get very attenuated to the horn.

OBJECTIVES OF THE INVENTION.

Taking into account the shortcomings of the prior art, it is an object of the present invention to provide a high-fidelity electrical circuit for medium frequency, simple construction and operation, reproducing horns, and yet high efficiency to avoid rupture of the cone. the speakers and reproduce the sounds without any distortion.

Another object of the present invention is to provide a high-fidelity electrical circuit for mid-frequency reproductive horns operating at very high powers. The above objects, as well as other objects and advantages of the invention, are achieved by providing a high-fidelity electric circuit for mid-frequency reproductive horns, which is connected between the output of the audio equipment and the horn of 3 _. at 6 inches in diameter, characterized in that it comprises a circuit generally constituted by two filters of different nature. One of the filters is a high pass filter with a cutoff frequency of 160 hertz, with 12 decibels / octave of attenuation; and the other of the filters is a low-pass filter with a cut-off frequency of between 1000 and 3000 hertz, with 6 decibels / octave of attenuation, wherein said filter combination has the advantages of reproducing the audible frequencies comprised between 20 and 3000 Hertz with an extraordinary quality, and protect from the rupture of the cone to any 3 V horn ?. 6 inches in diameter, even in high power conditions. Therefore, the lower attenuation band of the circuit that goes from 20 hertz to 160 hertz operates in this way as a voltage regulator with 12 decibels / octave of attenuation.

BRIEF DESCRIPTION OF THE DRAWINGS.

The aspects that are considered characteristic of the present invention will be established with particularity in the appended claims. Nevertheless, the invention itself, both by its organization, together with other objects and advantages thereof, will be better understood in the following description of certain modalities, when read in relation to the accompanying drawings, in which: Figure 1 is a simplified schematic representation of a variety of prior band pass filters. Figure 2 is a simplified schematic representation of the high-fidelity electric circuit for mid-frequency breeding horns of the present invention.

DETAILED DESCRIPTION OF THE INVENTION.

With particular reference to Figure 1, it shows various arrangements of possible bandpass filters as is known in the art. Each of the diagrams shown in said Figure 1 comprises a series of coils designated with an "L", capacitors or capacitors and a speaker designated with a "B", arranged in an array both in series and in a parallel. The connections of these bandpass filters have the same function without taking into account the number of elements that compose them, that is, the main function is to allow a certain band of frequencies to pass freely towards the speaker. As shown in Figure 1, there are exemplified various arrangements of the prior art bandpass filters which may comprise from 2 elements to 8 elements. However, it should not be construed that arrays of prior art bandpass filters are limited to those illustrated herein, as these may vary depending on the specific attenuation characteristics. However, without taking into account the type of arrangement or specific arrangement of the elements of said filters, all the bandpass filters known in the art have as their main function to freely pass a band of frequencies ranging from 500. up to 4000 hertz. The number of elements and the availability of these within the bandpass filters have as their function only and exclusively the number of decibels / octave that is desired in the lower and upper bands of filter attenuation. For example, for filters comprising two elements, that is, a L-speaker and a capacitor in series or parallel, the attenuation in both the upper and lower bands is about 6 decibels / octave. Also, for four-band pass-band filters, the attenuation bands are 12 decibels / octave, for 6-element filters the attenuation bands are 18 decibels / octave and finally for the 8-element filters, the attenuation bands They are 24 decibels / octave. As can be noted, in all typical pass-band filters the lower and upper attenuations for each case are always equal, that is, either they are 6 decibels / octave in the lower and upper attenuation band, or they are 12 in the lower band or higher, etc. The decibels / octave of attenuation are left to the discretion of the designer, however, there are no band-pass filters with 12 decibels / octave of attenuation in the lower band and 6 decibels / octave of attenuation in the upper band. This is not allowed by the filter theory as mentioned below. In accordance with the present invention, a high-fidelity electric circuit for mid-frequency reproductive horns is provided here comprising a three-element bandpass filter, which has a bandwidth from 20 hertz to 3000 hertz, and whose band of Lower attenuation is used as a voltage regulator so that the coil does not distort, and the cone does not break if it operates at high powers. It is known that a media horn is capable of reproducing very well, by its constructive characteristics, all frequencies between 500 hertz and 4000 hertz as a rule. Within this range of frequencies that any horn can reproduce, it is called the frequency response of the horn, and this is the only criterion that is generally taken for the design of any filter. That is, if the frequency response of the media horn is 500 hertz to 4500 hertz, then as a rule the pass band of the filter will be from 500 hertz to 4500 hertz. Modifying the design for a typical bandpass filter to encompass a frequency range of 20 hertz to 3000 hertz of the invention has two major drawbacks. First, to get the passband to start at 20 hertz, very large value coils would be needed according to the filter theory, which would result in obviously expensive coils. Second, the two upper and lower attenuation bands would necessarily be equal according to said filter theory, and what is required are 12 decibels / octave in the lower band and 6 decibels / octave in the upper band. Referring now to Figure 2, there are shown elements constituting the high-fidelity electric circuit for mid-frequency breeding horns of the present invention. As we can see, the electrical circuit is formed by three basic elements: a capacitor or capacitor 1 and a pair of coils 3 and 4. The capacitor 1 is connected at one end to the positive terminal 6 coming from the audio equipment output and through the opposite end is connected to a common node 2. The coil 3 is connected by one of its ends to the common node 2, while the opposite end of the coil 3 is connected to the negative terminal 7 coming from the output of audio equipment. Alternatively, the coil 4 is connected at one end to the common node 2 and at its other end to the positive terminal of the horn 5. The negative terminal of the horn 5 is connected to the negative terminal 7 coming from the output of the audio equipment and that it corresponds precisely to the electrical earth of the system as illustrated. The connection formed by the capacitor 1 in the coil 3 serves to attenuate the input frequencies which are dangerous for the rupture of the cone of the horn 5. Generally, the frequencies coming from the audio equipment (or input) that can break the cone they are between 20 and 160 hertz, that is, frequencies greater than 160 hertz freely pass to common node 2 without being attenuated. In this way, the arrangement formed by the common node 2 with respect to earth or terminal 7 to the left, constitutes the high-pass filter of the present invention. Preferably, said high-pass filter is formed by two elements (capacitor 1 and coils 3) with a cut-off frequency of 160 hertz and 12 decibels / octave of attenuation, and that precisely this attenuation band is the one that operates as a regulator of voltage to protect the horn 5 from low frequencies between 20 and 160 hertz. It is important to mention that the applicant has surprisingly found that said electrical circuit arrangement mentioned above, uses a pass-high filter attenuation band as a voltage regulator, which has never been used before for this purpose. Coil 4 will have the function of attenuating frequencies that can be annoying to the human ear or very acute. Normally frequencies higher than 3000 hertz are those that are attenuated with said coil 4, to produce a soft and sweet sound without any distortion. Therefore, the connection formed by the common node 2 towards the horn 5 forms a low-pass filter with a cut-off frequency comprised between 1000 and 300 hertz and 6 decibels / octave of attenuation. The values of the coils and capacitors of each filter are easily obtained by means of formulas duly established by the theory of electric filters, and are well known by a specialist in the field. In a preferred embodiment of the present invention, the capacitor 1 has a value of 235 microfarads, the coil 3 will have a value between 1 and 1.5 millihenrys, and the coil 4 will have a value between 0.100 and 1.5 millihenrys. However, it must be understood that the values are not limited to these. As can be seen from the aforementioned, the present invention consists of a high-fidelity electrical circuit comprising the unique combination of two filters with different attenuations. One passes high (input) with 12 decibels / octave of attenuation and the other passes low (output) with 6 decibels / octave attenuation. In addition, the two filters exhibit a different nature and different attenuations that are used in an electrical array operating in a similar way to a band-pass filter., but presenting the advantages of reproducing the audible frequencies between 20 and 3000 hertz with an extraordinary quality and protecting from the rupture of the cone any 3 Vz to 6 inch diameter speaker, even in high power conditions. Therefore, the lower attenuation band of the circuit that goes from 20 hertz to 160 hertz operates in this way as a voltage regulator with 12 decibels / octave of attenuation. Although particular embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, it is intended to protect in the appended claims any changes and modifications that are within the scope of this invention.

Claims (5)

CLAIMS.

1. - A high-fidelity electric circuit for mid-frequency reproductive horns, which is connected between the output of the audio equipment and the 3 Vz horn at 6 inches in diameter, characterized in that it comprises: a high-pass filter with cutting frequency located at 160 hertz, with 12 decibels / octave of attenuation; and a low-pass filter with a cutoff frequency between 1000 and 3000 hertz, with 6 decibels / octave of attenuation.

2. The electrical circuit according to claim 1, further characterized in that the circuit is formed only by three elements connected by one of its ends to a common node or point.

3. The electrical circuit according to claim 2, further characterized in that said elements constituting the circuit are an equivalent capacitor and two coils.

4. The electric circuit according to claim 1, further characterized in that the high pass filter serves as a voltage regulator.

5. The electrical circuit according to claim 4, further characterized in that said filter passes high prevents rupture of the cone of the speaker when operating at high power