You decide to make a subwoofer yourself. Do you already have a woofer, or have you looked for a suitable one in the store. Where to begin? Here we will consider not the electronic circuit, but only the reproducing part, i.e. the subwoofer itself: a case with a dynamic head.
In addition to good speakers for high-quality bass reproduction, it is important to correctly calculate the volume of the speaker box and know some of the subtleties of its manufacture. A homemade subwoofer must have an optimal box size. Whether it's a system in a car or a homemade subwoofer, a good cabinet is the most important component that affects sound quality.
Let's remember what sound is all about. This is a wave. Our ear is able to pick up vibrations with a frequency ranging from a few tens to about 20,000 Hertz (cycles per second). This range of waves is considered sound, in fact it is slightly wider. What we do not hear because of the very low frequency is infrasound, and the higher frequency, also not audible to us, is ultrasound (animals, for example, dogs hear it). sound wavespropagate only in a medium with sufficient density. We hear sound because we are in such an environment (air).
The subwoofer reproduces the lowest frequencies up to several hundred Hertz. The sound wave is created by the movement of the diffuser plane (movable speaker diaphragm). Its movement is transmitted into the air, and there is a sound that we hear. It turns out something similar to the operation of a pump. The main task of the subwoofer enclosure is to obtain high-quality sound. A speaker without a box is not capable of this, because for the emergence of a high-quality sound wave, we need only one of its phases, and an open speaker gives us two at once: positive and negative (the front and rear sides of the diffuser membrane). It turns out the so-called acoustic short circuit, very unpleasant for the ear. To separate the phase of the sound from one another, the speaker box serves.
Homemade subwoofers come in a variety of designs. The most common ones are with one speaker that goes outside, like on a regular speaker, but there are more complex devices.
As you understand, in order to separate the sound phases (how to close one of them inside the subwoofer case), its greater rigidity is needed so that the body itself does not transmit vibrations into the air. Therefore, the quality of the material plays a big role. The stronger it is, the better the result.
Remember that the most unfortunate option for any subwoofer is a symmetrical design. As a rule, the speaker is shifted away from the center. It is also not recommended to make a homemade subwoofer in the formcube, the sides must differ in size. All this is done to avoid resonance. Homemade subwoofer must have sufficient internal volume. If it is not enough, then the low-frequency sound is noticeably weakened due to the strong pressure inside the box, which is created by the operation of the membrane. If you need a homemade subwoofer of small volume, then you need to take a woofer with a smaller diameter, because. the recommended volume of the box directly depends on the size of its diffuser.
The table shows recommended sizes.
| Diffuser | Case Volume |
| 8 | 50-30 |
| 10 | 10-50 |
| 12 | 15-65 |
| 15 | 30-105 |
| 18 | 40-200 |
But it's best to check the documentation for your speaker.
