What is a subwoofer amplifier
Understand what a subwoofer amplifier is for a complete audio experienceA subwoofer amplifier, or simply “subwoofer” for our purposes here, is a self-amplified speaker dedicated to producing those low, deep bass sounds in music and movies. They deliver the rumble of a subway system in a big-screen production, and the exaggerated “wub-wub-wub” of the latest Skrillex tune.
Once upon a time, the only people who ever had use of a subwoofer were serious music aficionados, or those wanting to beef up their car stereo systems to the point of rattling the store window glass of establishments as they drove by.
These days, however, the rising trend away from large floor speakers, and toward smaller and smaller speakers in the home for that desirable yet discreet surround sound effect, has made owning a subwoofer for in-home use almost a necessity.
In the olden days, large costly cabinet speakers would cover the gambit of frequencies needed for most purposes. The small “satellite” speakers which are so popular these days, however, only produce high and midrange frequencies.
Subwoofers, on the other hand, do not produce any frequencies over approximately 150 Hz or so. They fill in the richness missing from the main speakers, to give the sound its full effect. Without a decent subwoofer, the sound emanating from these more aesthetically pleasing main speakers will sound tinny and flat. They lack the depth and fullness of full quality audio.
You will frequently see an in-home stereo system set up with two main speakers (a left and a right) and one subwoofer, which will sit on the floor or in an entertainment cabinet. The reason most systems only use one subwoofer is because, for most systems, you only really need one.
A good subwoofer will direct the sound out, and then those low frequency waves will reflect off the surrounding surfaces and back to the ear. This creates a sound which seems to be coming from “everywhere,” so that the placement of the actual speaker cabinet is irrelevant, as long as the room itself doesn't have any major acoustical issues. This is in contrast to the placement of the higher frequency speakers, which need to be placed strategically to deliver the best sound to the room.
Subwoofers come in different directional variations, namely down-firing and front-firing. Front-firing units have speakers which direct the sound out through the front and sometimes even the sides. These can be mounted, but can also just as easily sit on the floor. Down-firing units do just what it sounds like—push the sound down to the floor. Both types work just as well.
Which you choose primarily depends on your preferences. Of course, if you live in an upstairs apartment, a down-firing subwoofer may incite your downstairs neighbors to make some more broom marks in their ceiling, so you might consider one that doesn’t blast bass directly toward their heads.
A decent self-amplified subwoofer will also, interestingly enough, make the rest of your sound system perform better. This is due to the fact that it takes a lot of energy to produce low frequency sounds, which can put stress on the other speakers as they attempt to fill in those bass frequencies.
Having a dedicated subwoofer can greatly reduce the strain on the rest of the system, leaving the other speakers to do what they do best—deliver those crisp clean higher tones for which they are designed—without competing with the subwoofer for power.