Microbuzzer.com · Posted on 08-08-2010 by microbuzzer

Recently, a client mentioned on the buzzer, speaker of the PA cavity why the overall impact of such a big sound reasons, as follows:

We know that buzzer, speaker of the PA cavity design, is often understood as follows:

1: to have sound chamber, from the PA with, as to why should tone chamber, not sure.

2: Sealing Tone asked if the seal is not good, then lead to poor bass.

3: Tone hole can not open too much, too, if open, will lead to smaller volume.

Buzzer, horn antenna with a similar function, namely, the energy conversion from the action, the speakers, the key device, which is the electrical energy to sound energy is fundamental to sound chamber Danshi subsidiary device determines its maximum output power and frequency response, then We discuss the sound system down is to get the most energy.

First give an example, we slapped the air, the air acting essentially equal to 0, if we take a particularly big fan, fan does not move, doing work on the air is equivalent to 0.

The fact is that doing work on the air the air occurs, if the frequency range we can hear is the sound.
Then by the above examples, we can hand a pole on the air doing work, that there is a maximum. We look at the following formula:

P = F × V

P is power, the power of doing work on the outside, F Weili size, V is velocity.

Note that the formula F is too small, or V is too small, they can not do work outside, the product of the decision only two values of external power.

Next we look at speaker is not the same as with the hand, is a diaphragm plus a power coil, diaphragm decide the size of fans, power coils correspond to the force.

Because the speaker’s diaphragm is not possible to change, unless another speaker, the speaker diaphragm, the frequency of power signal certain circumstances, to describe the sound system should be how to improve the output energy:

Contrast P = F × V formula, we do work outside speakers present a simple formula specific.

Because F is proportional to the diaphragm area (S), so written as F = K × S, K as the coefficient.

V decision by the speaker of the power coil, coil power from the electric power generation, power resistance of the coil produced by the two parts, one of air resistance on the diaphragm (K × S), against the diaphragm vibration, but the speaker’s own diaphragm the stretch against the diaphragm vibration (Fz).

The sound system is generally much less than K × S Fz. The reasons are as follows. See a sound system, at every turn is like 100W, but the size did not sound much, is said to loud singing of a person for a year to produce energy can only burn a pot of water, visible, or very little sound energy, and must Most of the sound system, its energy consumption are on the trumpet, the heat.

So air can not affect the power coil, V must be considered.

Then the formula becomes P = K × S * V
because certain signals, the speaker diaphragm area S has a certain, If you want to change the P, the only change in K, the purpose is to increase K, in fact on the tone chamber K decided as follows:

If we double the current air density, K doubled, if only part of the air acting, you can enhance the force generated, because the aerodynamics dV / V = dF / F, which means that some do work on air space, air volume change with the change of power is proportional to. This is the sound cavity theory is to set aside part of the air, improve the K value, the speakers do work in this part of the air to produce sound, then this part of the energy and then spread to the whole space, here regarded as a sound chamber energy transfer Zhong Jian link.

More reasonable explanation of the above-mentioned first point, why should PA chamber, 2,3 can be similar to the analysis, for 2, still need to analyze the sound of the phase problem, because the buzzer, speaker there are two sides can considered as two sources, phase 180 °, for the third point, can be integrated into the first point, the K values are affected.

Targeted at small portable sound chamber design.

Tags: , ,
Posted in TECHNOLOGY | Comments (0)