Subwoofers - The most misused speaker

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What is a subwoofer?

And why do we need them, is probably the most revealing question. Since the 1980s, subwoofers have been used in some of the most insane installations, especially car audio. Since the discovery of Rap music—now often called Hip-Hop,the bass-centric genre set the stage for some of the most punishingly powerful bass sub systems in the world. It wasn't orchestral music that started this trend, I assure you, not that it couldn't benefit from it.

Many people believe a subwoofer is the compliment to a small speaker system, such as a bookshelf speaker stereo, or that it's the bass component in a multi-driver system. Many believe that s subwoofer is the single most powerful component for bass in any cinema system, and the one that should move your chair around when a giant helicopter storms into the movie screen.

Guess what? They're wrong. That's not a subwoofer. That's a woofer. And boy does this confusion ruin some potentially great sound systems! Worse, subwoofers are mostly used as woofers, and this could not be more inappropriate.

A subwoofer is a woofer by design, but it's not a woofer in [proper] use. A subwoofer is used to compress air in the listening room beyond the capability of a standard woofer. It is not meant to provide bass as the only source. It's used to compliment an existing full-range system—not to be used in lieu of one.

If you can hear it producing bass, it's a woofer.

We need to stop misusing the speaker and the term.

Why use a subwoofer?

Many audiophile full-range systems can produce enormous amounts of natural bass, some even down to 20 Hz. However, if you understand rooms and acoustics, you know the difference between directional waves and pressure. Sub-bass isn't directional. It's transmitted by compressing and UN-compressing the air in the room. The problem is, as the room grows in size, the 10" or 12" woofer struggles to judiciously compress the air in that room, and deep bass weakens.

A subwoofer begins its job at the very bottom of the capability of the woofer. Once the woofer exhausts its ability to properly compress the air in the room, thereby losing strength to produce frequencies down to 20Hz, you need more diaphragm area to aid. Subwoofers provide that small amount of added area from which to compress air in the room. Some subs move massive amounts of air, when called upon, and without a sweat if using their internal amplifiers.

Subwoofers can also be used to help fill nulls in the bass region from the room's shape and size. While a woofer will most definitely exhibit some deficit in a deep low-end frequency or two, a subwoofer might be used to help correct that by filling the void of the null. The sad reality is, many sub-owners never realize this.

Did you know that subwoofers often aren't best placed next to the speakers?

Subs are often criminally misplaced due to the lack of understanding in how to properly use them. For example, a single sub placed in between two full range speakers is probably the single worst placement for it. Placing the sub directly between two speakers that also produce bass could not only negatively compound bass level in the same strong frequency ranges of the main speakers, but could also "suck-out" bass some frequencies from the main speakers! It's awful.

Something I heard once I'll never forget: "It's pretty good, but when that one bass note hits, your teeth rattle! Here it comes!" -The poor, grossly misled soul who said it.

A sub that sounds good at some bass frequencies, but rips your head off at others, is absolutely improperly deployed.

Sometimes subs perform best from the rear of the room. Sometimes, they perform even better from the sides. Sometimes, the corners. It's difficult to predict. The best method I've understood for placing them, is to temporarily place one where you sit. Play familiar sources through it and walk around the room, listening for the most balanced bass frequency response (not the loudest!). Once you find that spot in the room. Plop! There's where your sub should live. Granted, that's a quick method, not scientific.

Armchairs-at-large

I've recently been responding to some very negative comments on a well-respected speaker builder's social ads. My goal is to help others see through the noise of worthless input. Many negative commenters in these ads would state things like, "You can find a superior sub from (Brand X) for 1/4 of the cost. Pass.". My response is, "Have you tried this brand? What were your findings? What methods and set up, including the room characteristics, did you use during your review?" (Silence).

Later, I see another ad, and the usual suspects pop-up again with swift unfair opinions. Again, I ask the same, if not similar questions to counter the unhelpful comments. Sometimes there's a response, sometimes, not. What I never see is any explanation, background, or qualifications to the negative comments. They only complain about the cost.

Even worse, some state "I heard this sub at (convention XYZ), and wasn't impressed." Now, this is unfortunate. Not only did the listener/commenter not give the sub its due, simply stating it was heard at a convention should be heavily taken with a grain of salt. Even the greatest of components are compromised by the rooms at conventions. I'm not kidding!

Nevertheless, the comments rage on. All I can do is just marvel at these expert opinion from afar, and only one day hope they do compare their own choices to the one advertised to be superior—Not that the superior sub will win. But that others may read more judiciously fair, and reasonable reviews.

Summary

If you're in the market for a subwoofer, it's worth first fully understanding what a sub is used for, what it provides, and how best to use one before spending the $$$. You will be more than pleasantly surprised at what can be experienced if done right. I promise!