Self-made subwoofer: we make the case

You decided to make a subwoofer yourself. You already have a woofer, or you looked at the one in the store. Where to begin? Here we consider not an electronic circuit, but only a reproducing part, i.e. Actually the subwoofer itself: the case with a dynamic head.

In addition to good speakers for high-quality reproduction of the bass, it is important to correctly calculate the volume of the box of the speaker system and the knowledge of certain subtleties of its manufacture. A self-made subwoofer should have an optimal box size. Whether it's a car system or a self-made home subwoofer, a good chassis is the most important component that affects sound quality.

Let's remember what sound is like. It's a wave. Our ear can detect oscillations with a frequency in the range of several tens to about 20 thousand Hertz (vibrations per second). This range of waves is considered to be sound, in fact it is a bit wider. What we do not hear because of a very low frequency is an infrasound, and a higher frequency, also not audible to us - ultrasound (it is heard by animals, for example, dogs). Sound waves propagate only in an environment having sufficient density. We hear a 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 plane of the diffuser (the movable diaphragm of the speaker). Her movement is transmitted into the air, and a sound appears that we hear. It turns out something similar to the pump.

The main task of the subwoofer enclosure is to get a 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 phase of it, and the open speaker gives us immediately two: positive and negative (the front and rear side of the diffuser membrane). It turns out the so-called acoustic short circuit, very unpleasant for the ear. To separate the phase of sound from one another and serves as a speaker box.

Homemade subwoofers have a variety of designs. The most common are with one speaker coming out, like on an ordinary speaker, but there are more complex devices.

As you understand, in order to separate the phases of sound (how to close one of them inside the case of a subwoofer), its stiffness is necessary, so that the body itself does not transmit vibrations to the air. Therefore, the quality of the material plays an important role. The stronger it is, the harder, 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. Also it is not recommended to make a self-made subwoofer in the form of a cube, the sides should differ in size. All this is done to avoid resonance.

A self-made subwoofer should have a 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 work of the membrane. If you need a self-made subwoofer with a 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 recommended dimensions are listed in the table.

But it's better to check the documentation for your dynamics.