Created on 24.10.2019 19:42.
Updated 10.24.2019 20:33.
Author: Orekhova O.V.
The invention relates to the field of electroacoustics, namely to the construction of coaxial acoustic systems with a horn high-frequency loudspeaker, and can be used for high-quality sound reproduction.
A coaxial speaker system is known, which includes a diffuser attached with a corrugation and a centering washer to a diffuser holder connected to a voice coil, a magnetic system, a high-frequency loudspeaker with a horn installed in the center of the diffuser (see PCT application WO 94/03024, IPC7H 04 R 9/06, 1994).
The disadvantages of the known acoustic system include an insufficiently high quality of sound reproduction due to significant nonlinear harmonic distortions associated with undesirable effects from the influence of sound waves reflected from the outer lateral surface of the expanding horn and from heating the magnetic system and voice coil, as well as a large weight due to large material consumption of the magnetic system.
The proposed invention is aimed at solving the problem of improving the quality of sound reproduction by reducing nonlinear harmonic distortion and intensifying heat removal from the magnetic system and voice coil, as well as reducing the weight of the speaker system.
This problem is solved by the fact that in a coaxial speaker system, including a diffuser attached with a corrugation and a centering washer to a diffuser holder connected to a voice coil, a magnetic system, a high-frequency loudspeaker with a horn installed in the center of the diffuser, ribs are made on the outer lateral surface of the horn, magnetic the system is made in the form of ring magnets installed coaxially on the central rod with the base and located inside the voice coil with a ring of magnetically conductive material between them, and a high-frequency loudspeaker with a horn is installed on the end of the ring magnet facing the diffuser.
The coaxial speaker includes a diffuser 1, attached with a corrugation 2 and a centering washer 3 to a diffuser 4 connected to a voice coil 5. The magnetic system is made in the form of ring magnets 7 and 8 ( having the opposite direction of polarity) with a ring 9 of magnetically conductive material between them.
A high-frequency loudspeaker (tweeter) 10 with a horn 11 (for example, exponential) is installed on the end face of the ring magnet 8 facing the diffuser 1; …
In a preferred embodiment of the coaxial dianmic, the cavity 13 located under the centering washer 3 on the side opposite to the diffuser 1 is in communication with the atmosphere, for example, by means of holes 14 made in the wall of the diffuser 4. Another cavity 15 can also be provided with holes 16.
A low or medium sound frequency current passing through the voice coil 5 excites an alternating magnetic field, which, interacting with the constant field of the magnetic system, drives the voice coil 5 and the diffuser 1, which, in turn, acts on the air environment, exciting sound waves of the corresponding frequency. Installed in the center of the diffuser 1, a high-frequency loudspeaker 10 of any principle of operation with a horn 11, which improves directivity and increases the sound pressure at high frequencies, generates high-frequency sound waves.
Sound waves arising under the horn of the horn 11 from the vibrations of the diffuser 1 fall on the outer side surface of the horn 11 and, instead of being reflected from it, as in the case of a smooth surface, and introducing nonlinear distortions, are damped and scattered by the ribs 12 made on this surface.
During the operation of the acoustic system, the voice coil 5 is heated and, accordingly, the air is heated in the area of its placement, as well as the magnetic system. Heat from the magnetic system, in addition to being dissipated through the base of the central rod 6, is effectively removed to the environment through the developed ribbed outer surface of the horn 11. Such two-sided heat removal is especially relevant when the entire magnetic system is placed inside the voice coil 5.
The heat from the heating of the voice coil 5 is removed, among other things, into the cavity 13 located under the centering washer 3 on the side opposite to the diffuser 1. An additional air inflow occurs through the holes 14 to cool the elements of the acoustic system. Also, in this case, there is a decrease in the undesirable effect of air compression in the cavity 13 when the diffuser 1 moves inside the system on the nature of its movement and, accordingly, on the characteristics of the acoustic system.
Source: patent RU 2 262 812 C1