A Guide to Subwoofers (Part I): Characteristics, Placement, & Adjustments

[Sir Terrence]

Corner placement: This is the advice that is given most often. Although corner placement will yield loud bass, it tends to make the music sound boomy. You should place your subwoofer in a corner only if it is not capable of producing deep bass. Putting a down-firing subwoofer in a corner is not a good idea.

I think this guide is excellent, but I do have an issue with just this one point. Corner placement will not always guarantee the sub will boom, it really depends highely on the geometry of the room itself, and where you are placed within it. It is quite likely you could place a sub in a corner, sit yourself in a low pressure zone like the middle of the room, and never hear a single resonant frequency from the sub. Corner placement will make a sub boom because it is exciting a room mode just like wind excites a resonant point when you blow over a bottle top. Corner placement excites all of your rooms modes, but it also supports low frequency output which is very important for keeping cone travel, and therefor distortion down. Corner placement will not make subwoofers that are deep bass deficent suddenly able to produce deep bass. All it will do is reinforce what bass it can produce.

According to Floyd Toole's research you should always place a sub in a corner, and use equalization to deal with audible peaks in the subs frequency response at that position. His theory is to place the sub where it performs the best, and equalize out the problems this placement causes. It doesn't make any difference whether the sub fires downward or outward, at the frequencies the sub covers, the wavelengths are so long it makes absolutely no difference what side the driver is on. Corner placement gives you additional output without any penalty on the subwoofer amp. Its free power that you can use to decrease distortion to both your driver and your sub amp directly.