JP4437839B1 - Speaker device - Google Patents

Abstract

The present invention provides a speaker device that retains the advantages of a flat baffle speaker that can reproduce a releasable sound that cannot be obtained by an enclosure speaker device, and solves the disadvantages of the flat baffle speaker.
An enclosure 6 includes a woofer 4, a duct 5, and a baffle plate 6 a on which a sound absorbing material 7 is pasted. The full range 1 is attached to the baffle plate 6a with the bolt 3 through the stay 2 while being bare in the same direction as the woofer 4, and the full range 1 and the woofer 4 are connected to the amplifier in parallel with each other without passing through a passive filter.
[Selection] Figure 1

Description

    The present invention relates to a speaker device that retains the advantages of a flat baffle speaker and solves the drawbacks.

    The speaker system for audio is mainly bass reflex type, sealed type, etc. with the speaker housed in the enclosure. Surrounding the back of the speaker with the enclosure eliminates the diffraction of the anti-phase sound generated before and after the cone and cancels the sound. Is prevented. In addition, by reducing the size of the enclosure, the back pressure is increased, the cone swing phenomenon in the low frequency range is suppressed, and the conversion efficiency to sound is increased.

    However, enclosing the back of the speaker with an enclosure makes it difficult to reproduce fine sounds with medium or higher sounds, and sacrifices sound quality such as the loss of open sounds.

  As an improvement measure, there is a method of using a flat baffle type speaker whose back pressure is the same as the pre-pressure.

  Seibundo Shinkosha supervised by Tamon Saeki New Edition Speaker & Enclosure Encyclopedia page 113 “The infinite baffle is a flat baffle, so there is no diffracting effect of the sound, and you can demonstrate the performance of the speaker under the best conditions. . "

Certainly, an infinite plane baffle-type speaker has the same front pressure and back pressure, and an open sound can be obtained.
The meaning of “open sound” used in the present invention is as defined in 1 to 6 below.

1. It is a sound that comes out brilliantly without sound. It is a so-called good sound.
2. The sound of each voice / instrument is not compressed, the original sound with a wide dynamic range can be maintained, and fine sounds such as overtones and reverberations are reproduced.
3. It is a sound with a good transient and excellent rise and fall, a sharp, punchy sound with a sense of attack.
4). It is a natural and straightforward sound with little nonlinear distortion.
5). It is a transparent sound with high resolution and resolution that is free from the reflected sound in the enclosure.
6). Sound is released from the standing waves in the enclosure.

Disadvantages of an infinite plane baffle type speaker are that the back pressure cannot be increased, so the overdamping speaker with a low Q ₀ value is insufficient in bass, the bass below the F ₀ value cannot be reproduced, and the speakers that can be used are The Q ₀ value is limited to 0.7 or more.
Also, when the front sound radiated from the speaker tries to go backward, it is reflected by being blocked by the baffle plate, causing interference with the sound in the forward and lateral directions, resulting in turbidity in the sound.

An infinite plane baffle is a theoretical shape and cannot be made. In reality, it becomes a finite size baffle, and then the following drawbacks appear.
1. When trying to reproduce low frequency bass, the baffle plate becomes huge.
2. In the range above the cutoff frequency, a peak appears at an odd multiple of the cutoff frequency, and a dip appears at an even multiple.
3. In order to suppress the peak and dip, there is a method of avoiding the center of the baffle plate as the speaker mounting position and irregularly forming the baffle plate shape, but the sound quality changes depending on the listening location.
4). In the lateral direction of the baffle plate, an 8-shaped dipole directivity that does not make sound is formed, which is not preferable for sound field reproduction.
5). Since the back side is open, the sound characteristics change depending on the situation of the back side when the speaker device is installed.
6). It is difficult to suppress the vibration of the baffle plate, the speaker is susceptible to vibration from the baffle plate, and the sound is turbid.

    Japanese Laid-Open Patent Publication No. 2006-191510 discloses a speaker device that is similar in concept to the present invention to improve sound quality. The speaker device of this publication has two speakers arranged in a perpendicular direction, and the sound emitted from the speaker is a spherical wave, so it can be said that the silencing effect is low. In addition, the sound of a specific frequency may be enhanced.

  When the sound is not sufficiently muted, the back of the speaker unit (A) of the speaker device of this publication is sandwiched between parallel side plates, and standing waves are generated on the left and right side plates. In addition, the front surface of the speaker unit (B) is surrounded by the front plate, the rear plate, and the left and right side plates, and operates as a horn, generating peaks and deps at specific frequencies.

  As a result of performing blind hearing with the speaker device of this publication, it is described that approximately 20 people have confirmed the effect. By removing the top plate, the speaker unit (A) that emits the sound has almost no internal reflection pressure, and the meaning of the internal reflection pressure here is understood to be the sound pressure due to the reflection sound in the enclosure. It is presumed that what is effective is that the air spring force (stiffness) before and after is the same and that an open sound is reproduced. However, from the viewpoint of the reproduced sound of the entire speaker system, it is difficult to say that the sound pressure frequency characteristics have peaks and dips, and that the sound quality is substantially improved.

JP 2006-191510 A

  The problem to be solved is to provide a new speaker device that solves the disadvantages while leaving the advantages of a flat baffle speaker and provides an open sound that cannot be obtained with an enclosure speaker device.

Specifically, all the following disadvantages 1 to 9 of the flat baffle type speaker are solved, and the speaker device of the present invention is small and can reproduce low-pitched sound. The sound can be reproduced and the original sound can be reproduced.
1. The baffle plate becomes huge for low frequency bass reproduction.
2. A dip occurs when the peak is an even number times the odd number times the cutoff frequency.
3. The sound quality changes depending on the listening location.
4). A lateral 8-shaped dipole directivity is formed.
5). The sound characteristics change depending on the situation on the back of the speaker device.
6). It is difficult to suppress the vibration of the baffle plate.
7). The direct sound of the speaker interferes with the reflected sound from the baffle plate, making the sound cloudy.
8). A low sound cannot be reproduced with an overdamping speaker having a low Q ₀ value.
9. F ₀ value following the bass can not be reproduced.

In order to solve such a problem, in the invention of claim 1, the enclosure 6 is provided with a woofer 4 and is provided with a duct 5, and the baffle plate 6 a is provided on the entire surface excluding the woofer 4 holes and the duct 5 holes. This is a speaker device for low-frequency reproduction to which a sound absorbing material 7 is attached.
However, when a sound of medium or high tone emitted from the back of the full range 1 reaches the baffle plate 6a, the sound absorbing material 7 absorbs the sound.
The full range 1 is bare in the same direction as the woofer 4 at a close distance on the same axis as the center line of the woofer 4 and is attached to the baffle plate 6 a with the bolt 3 through the stay 2.
However, since the full range 1 is attached in a bare state, the generation of standing waves due to the sound radiated from the front surface of the woofer 4 is eliminated.
Since the back of the full range 1 is not surrounded by the enclosure, it is free from the reflected sound from the inside of the enclosure, and becomes a transparent sound with high resolution and resolution.
Since Full Range 1 is not attached to the baffle plate, it is free from harmful vibrations of the baffle plate, and when the sound radiated from the front of Full Range 1 turns back, reflection does not occur on the baffle plate and direct sound is heard. There is no interference.
The full range 1 and woofer 4 are connected to the amplifier in parallel so that they do not pass through the passive filter and vibrate in the same direction.
However, a capacitor that advances the current phase, or a passive filter such as a high-pass filter or low-pass filter that uses a delayed coil is not used, and the phase of the back sound of the full range 1 and the sound of the woofer 4 is completely reversed.
The greater the distance between the back of the full range 1 and the front of the woofer 4 and the higher the frequency of the radiated sound, the greater the phase difference and the lower the silencing effect. By placing Full Range 1 close to the center line coaxially of woofer 4, the distance between the two sound sources is minimized, and the back sound of Full Range 1 and the sound of woofer 4 are completely out of phase. It can mute to high frequency range with high efficiency.
Since the back sound of the full range 1 is muted, the bass characteristics of the present invention depend on the bass playback speaker device of the enclosure 6 and can be played back in a small size.

    According to the present invention, by solving the drawbacks of a flat baffle speaker, bass that exceeds the bass reproduction limit of the flat baffle speaker can be reproduced in a small size, and the peaks and dips peculiar to a flat baffle speaker are eliminated. There is no change in sound quality depending on the listening location, there is no change in sound characteristics depending on the installation location, there is no interference between the direct sound and the reflected sound of the baffle plate, and there is an advantage that the reproduced sound close to the original sound can be obtained. is there.

Further, the full range that can be used is not limited to those having a Q ₀ value of 0.7 or more as in the case of a conventional flat baffle type speaker, and there is an advantage that overdamping with a low Q ₀ value is possible.

  Furthermore, the sound reproduced from the speaker device of the present invention has an advantage that an open sound that cannot be achieved by the improvement of the full range unit housed in the enclosure type speaker device can be obtained.

    The speaker device of the present invention is low in cost because it can be realized by using an inexpensive one without using an expensive full range or woofer.

  FIG. 1 is a side sectional view of a speaker device showing Embodiment 1 of the present invention, where the diameter of the full range 1 is smaller than the diameter of the woofer 4. Enclosure 6 has the required volume according to the characteristics of woofer 4 (with a diameter of 16 cm). The mounting position of the woofer 4 and the duct 5 and the length of the duct 5 are the required values of the woofer 4 characteristics. The sound absorbing material 7 is pasted on the entire surface of the baffle plate 6a excluding the woofer 4 hole and the duct 5 hole.

  The stay 2 attached to the full range 1 (with a diameter of 12 cm) is formed with a minimum area so that the baffle effect does not appear, and is made of metal such as iron, brass, or aluminum and has sufficient strength to support the full range 1 Use something. Bolt 3 uses a bolt with the same strength as the full range 1 mounting screw, such as iron or stainless steel.

  The mounting position of the full range 1 is arranged on the center line coaxial with the woofer 4. The distance from the woofer 4 is arranged as close as possible so that the sound absorbing material 7 attached to the full-range magnet 1c in FIG. 4 does not come into contact with the cone (not shown) of the woofer 4 when the woofer 4 is driven.

  Fig. 4 A sound absorbing material 7 is attached to the side surface and bottom surface of the full range magnet 1c for the purpose of absorbing medium and high sounds radiated from the woofer 4 in a linear direction.

  The electrical connection between full range 1 and woofer 4 does not pass through a passive filter such as a high-pass filter or low-pass filter, and is connected to an amplifier (not shown) in parallel with the positive pole so that the vibration direction is the same.

  When the output sound pressure characteristics of full range 1 and woofer 4 differ by 3 dB or more, adjust with an attenuator using a resistor to obtain the same sound pressure to obtain a flat output sound pressure characteristic.

  The operation of the first embodiment configured as described above will be described. When full range 1 is driven alone, the distance L from the center of full range 1 to the end of full range frame 1b in FIG. 3 is 6.3 cm, and the cut-off frequency is 4,250 cm / 6.3 cm = 675 Hz (Forex Company) Issued CRAFFT HAND BOOK SPEAKER CRAFT MANUAL VOL.

  Next, when the woofer 4 is driven simultaneously, the back sound of the full range 1 is muted by the sound of the opposite phase radiated from the woofer 4. If the back sound of the full range 1 turns to the front of the full range and cancels the front sound before the sound of the woofer 4 reaches the back of the full range 1, the canceled frequency component disappears, and the sound of the woofer 4 is muted. There is nothing, and the sound of the woofer 4 is radiated to the outside with the same sound pressure. Therefore, the sound pressure characteristic below the cutoff radiated to the outside is close to the sound pressure characteristic of the speaker device for enclosure 6 bass reproduction, and good bass characteristics can be obtained.

Because of this operation, the full range 1 can use an overdamping speaker having a low Q ₀ value.

The limit value of bass reproduction depends on the bass reproduction ability of the enclosure 6 bass reproduction speaker device, not the full range 1 F ₀ value.

  The straight line distance from the front end position of the front face of the full-range cone 1a of Example 1 to the front end position of the woofer 4 cone (not shown) is 5.6 cm, and the frequency range where the sound can be silenced is 34,00 cm ÷ (5. 6cm x 2) = 3,036Hz or less, and the sound can be silenced from low to high frequencies.

The sound radiated from the rear surface of the full range 1 toward the baffle plate 6a is silenced between the rear surface of the full range 1 and the baffle plate 6a, but reaches the baffle plate 6a due to the independence of the waves based on the principle of wave superposition. The mid- and high-pitched sounds that reach 1 KHz or more are absorbed by the sound-absorbing material 7 to eliminate reflection.
Sounds lower than 1 KHz are reflected without being absorbed as the frequency decreases. This reflected sound is secondarily muted by the sound of woofer 4.

  Medium and high sounds emitted from the woofer 4 in the straight direction are radiated by the full range magnet 1c shown in FIG. 4, and are absorbed by the sound absorbing material 7 attached to the full range magnet 1c so that the sound is not turbid.

  Due to the above noise reduction and sound absorption measures, the peak at odd multiples of the cut-off frequency and the dip at even multiples are not felt. Therefore, the deterioration of the sound quality due to the listening position other than the change of the sound quality due to the directivity characteristics of the full range 1 is not felt.

  The back sound of the full range 1 is silenced and absorbed, and since the distance of the back surface of the full range 1 is fixed by the baffle plate 6a, the characteristic does not change depending on the installation location unlike a flat baffle type speaker.

  In the lateral direction of the full range 1, even if the front and rear sounds of the full range 1 are canceled due to diffraction phenomenon, it is compensated by the sound in phase with the front sound of the full range 1 radiated from the woofer 4, so an 8-shaped dipole directivity is formed. Not.

  As described above, the speaker device of the present invention solves the disadvantages of the flat baffle type speaker and further exceeds the limit value of the conventional flat baffle type speaker in terms of low sound reproduction capability.

  FIG. 5 is a side cross-sectional view of the speaker device showing the second embodiment of the present invention. The purpose of the second embodiment is to use the same full range 1 instead of the woofer 4 and have a sound pressure with a very similar anti-phase sound wave. This is to improve the silencing efficiency by utilizing the frequency characteristics.

Enclosure 6 has the required volume according to the characteristics of full range 1 (with a diameter of 12 cm and an overdamping with a Q ₀ value of 0.25). The mounting position of full range 1 and duct 5 and the length of duct 5 shall be the required values for full range 1 characteristics. A sound absorbing material 7 is pasted on the entire surface of the baffle plate 6a except for the full range 1 hole and the duct 5 hole.

  The full range 1 attached to the baffle plate 6a is attached to the baffle plate 6a together with the full range 1 housed in the enclosure 6 with bolts 3. For the mounting bolt 3, use steel, stainless steel, etc. having the same strength as the full-range 1 mounting screw.

  Since other implementation methods are the same as those in the first embodiment, a description thereof is omitted.

  In FIG. 3, the distance L from the center of the full range 1 to the end of the full range frame 1b is 6.3 cm 3, and the cut-off frequency is 4,250 cm ÷ 6.3 cm = 675 Hz.

  The linear distance from the front end position of the front surface of the front full-range cone 1a of the second embodiment to the front end position of the front surface of the rear full-range cone 1a is 6.4 cm, and the frequency range where the sound can be silenced is 34,000 cm ÷ (6.4 cm × 2 ) = 2,656 Hz or less.

Since the limit value of bass reproduction in Example 2 depends on the bass reproduction capability of the enclosure 6 bass reproduction speaker device, it can be reproduced to a low frequency range below the F ₀ value even though the full range 1 of overdamping is used. .

FIG. 6 is a side sectional view of the speaker device showing the third embodiment of the present invention. The purpose of the third embodiment is to use the full range 1 having a Q ₀ value of 0.7 or more and the enclosure 6 is small. This is for reproducing a bass sound lower than the F ₀ value of the full range 1.

  In Example 3, the diameter of the full range 1 is 16 cm, and the diameter of the woofer 4 is 13 cm. That is, the diameter of the full range 1> the diameter of the woofer 4.

  The enclosure 6 has a required volume according to the characteristics of the woofer 4. The installation position of the woofer 4 and the duct 5 and the length of the duct 5 are required values of the woofer 4 characteristics. The sound absorbing material 7 is pasted on the entire surface of the baffle plate 6a excluding the woofer 4 holes and the duct 5 holes.

  The bolt 3 that attaches the full range 1 to the baffle plate 6a is a strong bolt such as iron or stainless steel having the same thickness as the full range 1 attachment screw.

  Since other implementation methods are the same as those in the first embodiment, a description thereof is omitted.

  In Example 3, the distance L from the center of the full range 1 to the end of the full range frame 1b in FIG. 3 is 8.3 cm, and the cutoff frequency is 4,250 cm / 8.3 cm = 512 Hz.

  The linear distance from the front end position of the front face of the full range cone 1a of Example 3 to the front end position of the woofer 4 cone (not shown) is 7.4 cm, and the frequency range in which the sound can be silenced is 34,00 cm ÷ (7. 4 cm × 2) = 2, 297 Hz or less.

The volume of the enclosure 6 that accommodates the full range 1 (diameter 16 cm, Q ₀ value is 0.7 or more) used in Example 3 is such that the bass reproduction limit approaches the F ₀ value according to the design of the prior art. Also, do not increase the back pressure because there is no bass peak near the bass playback limit. However, the enclosure 6 of the third embodiment of the present invention has a capacity of 10? Therefore, it is possible to reproduce a bass sound lower than the full range 1 F ₀ .

It is a sectional side view of the speaker apparatus which showed Example 1 of this invention. It is a front view of the speaker apparatus which showed Example 1 of this invention. It is a schematic front view of the full range used by this invention. It is a schematic side view of the full range used by this invention. It is a sectional side view of the speaker apparatus which showed Example 2 of this invention. It is side sectional drawing of the speaker apparatus which showed Example 3 of this invention.

1 Full Range 1a Full Range Cone 1b Full Range Frame 1c Full Range Magnet 2 Stay 3 Bolt 4 Woofer 5 Duct 6 Enclosure 6a Baffle Plate 7 Sound Absorbing Material

Claims (1)

The enclosure 6 is a speaker device for low-frequency reproduction in which a woofer 4 is attached, a duct 5 is provided, and a sound absorbing material 7 is pasted on the entire surface of the baffle plate 6a except for the woofer 4 hole and the duct 5 hole. The full range 1 is attached to the baffle plate 6a with the bolt 3 via the stay 2 while being bare in the same direction as the woofer 4 at a short distance on the coaxial line of the center line of the woofer 4. The connection of the full range 1 and the woofer 4 to the amplifier A speaker device characterized in that the positive electrode is arranged in parallel so as to vibrate in the same direction without passing through a passive filter.

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