When I got interested in whatever it sounded like, home subwoofers were nice special devices that only catered to two high profile fan groups: those who listened to great organ performances and those who loved reggae! It happened a long time ago and today more subwoofers are seen as a home acceptance factor than a potential specific benefit – almost a standard component of modern self-recording and learning systems. .

However, a special loft is specifically required for a Low Frequency Effects (LFE) channel for 5.1 home theater room systems. The fact is that this downstream user typically uses a two-channel control (explained later) to cover the bass portion of the main five channels but a convenience that allows for the use of smaller speakers. I’ll come back to this later, but I’ll go over the 2.1 stereo controls first.

Advantages of the subwoofer

Properly built and used, subwoofers can be extremely efficient and comfortable. But it’s also very easy to spoil any possibility with an unsuitable or poorly mounted subwoofer for good quality control – and it should be noted that I’ve seen nine unsatisfactory setups on each item!

Improper subwoofer installation usually results in too much bass or poor definition. There is often a significant difference in the spectrum between the satellite speakers and the subwoofer. It is an intersectional integration that creates or destroys the system as a whole.

The worst type of subwoofer system will only deliver loud or monotonous “woomf” energy regardless of the subwoofer height or dynamics, and thus the bass may feel viscous or slow compared to the main speakers. On the other hand, a well-tuned system (due to the lower levels of distortion and intermodulation) and an overall performance higher than that which could not be achieved will usually result in a sharper image and a brighter, more transparent center. .

In practice, it is much easier to get the satellite and subwoofer combination and get around. Standalone speakers are denser and lighter than full-size speakers, and this is often an important consideration, especially in small home studios and position recorders.

The purpose of this article, therefore, is to explain how and why a subwoofer is selected and used for a stereo and surround sound program.


The first thing you need to understand is the basic concept of a subwoofer system. What is it trying to do and how does it work? Clearly, the basic idea is to reproduce the low frequencies. In most cases this is about two lower octopuses, between 20 Hz and 80 Hz. But here is the first big problem that needs to be solved: there is no special subwoofer that generates low frequencies in the listening room – far from it. !

The acoustic properties of the room itself are crucial. If you put the world’s best subwoofer in a poor fitness room, you get really bad bass! Many times I have come across tracking systems where the owner has added a subwoofer in hopes of handling weak or unbroken bass and have found that the situation is no better or worse!

If your camera has major problems with constant radio waves – and it is in almost every home studio – it is imperative that these acoustic problems are resolved before spending any money or time on the subwoofer.

Bass trap to control and reduce permanents in space is a topic we have discussed often, as well as a popular topic for ongoing discussions and advice in the Studio Design & Acoustics forum on the SOS website.

Sometimes, with a few simple handwork, you can dramatically improve room acoustics at the lowest cost. And with the room treated, you’ll find that your existing speakers deliver far more and better bass than you’d expect!

Another useful advantage of the subwoofer is the additional management of the power assigned to the entire system. The acoustic energy of music is greatest at low frequencies and decreases with frequency. By using a dedicated box to manage much of the power base, this load is removed from the satellites, which offers advantageous advantages in terms of overall electrical control and clarity.

One or two?

Most stereos have two main speakers, but we only have one subwoofer. Why not two subwoofers? In some cases two (or more) substrates may be useful, but usually one is sufficient. This happens because our hearing measures the sensory difference between sounds that reach each ear at frequencies below 700 Hz, but mainly higher level differences. Outwardly, our ability to determine the direction of sound at very low frequencies is still quite accurate, but that ability falls apart when we hear inside. Sources that produce sounds at low frequencies (below about 100 Hz) vary them everywhere (the sound wave propagates in all directions from the source) because the length of the sound is generally greater than the length of the object itself. the frequency sound is generated internally, the spherical sound waves generated reflect the spatial boundary surfaces with different phase fluctuations due to the different lengths of the return path to the ears. This signal mixing prevents a reliable phase difference between the ear and the brain, so that the normal handler fails.

Since in theory you can’t see where the low frequencies are coming from in the room, a subwoofer is enough. Satellite speakers reproduce bass harmonies – which typically start above 90Hz – and provide a lot of directional information with phase and level differences in the usual way. So while the bass itself is money, the stereo craftsmanship is still pretty good.

Bass control

Bass control is the process of removing the key element from the signal sent to each satellite speaker and sending it to one or more secondary servers. In principle, this is not the same as in the normal crossover network – the subwoofer is only in a separate box and must have a combination to connect at least two bass input channels.


The physical and electrical configuration of the subwoofer is a poorly understood process, but the misunderstanding destroys the accuracy of the monitoring system as a whole. First of all, it is important that all speakers and satellite speakers are in phase, I mean their electrical polarity and their time. Otherwise there is a free arc or drop level at their intersection. There are many potential sources of phase changes that could destroy the intersection. In addition to the electrical phase properties of the cross filters themselves, there is a broad mechanical response to the phase. Additionally, the delay causes the speakers to be at different distances from the listener, and some cabinet designers introduce additional acoustic delays, often at very different frequencies.

Suitable place

Ideally, the subwoofer and satellite system are configured with appropriate acoustic measurement equipment, but few of us have the access or experience to correctly interpret the results. Fortunately, however, if you take your time and patience and follow a logical approach, you can usually get very good subjective results.



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