Subwoofers Do You Need More Than One?

NewsletterSubwooferWhen showing off their home systems, most owners look to crank songs and movies that create the biggest booms. These house-banging sounds are driven by subwoofers, which reproduce the lowest frequencies in your audio system – the bass. A quality subwoofer provides the foundation for amazing music and adventure movies that shake the room. But is one properly placed subwoofer enough?

Depending on the space, acoustic experts may recommend more than one subwoofer because with just one sub you can have locations in a room that have too much bass and others that have too little. Sometimes you can have overblown bass in one seat, and just a few feet away another chair there seems to be almost no bass.

This phenomenon can be illustrated by the following analogy; imagine you have a rectangular bucket—the shape of most rooms—about half filled with water. You drop a stone in the bucket, the stone will create concentric circles of waves radiating out on the surface of the water, just like a subwoofer creates waves of bass. When these waves hit the wall of the bucket, they will bounce back striking other waves. When two waves smack into each other they can sometimes double in size or they can cancel each other out.

This is not a perfect analogy. The way sound behaves in a room is much more complex; the sound waves in rooms react to each other in three dimensions and the bucket example is only in two dimensions. But the same thing can happen in rooms; the waves of sound in the bass frequencies from the subwoofer bounce against the walls, floor and ceiling and often double or cancel the sound waves out. This can result in too much or too little bass.

Proper placement of one subwoofer can minimize this problem in some rooms, but not all. Whether more than one sub is needed depends on the shape and size of the room, the location of the seats and the acoustical properties of the room. Two identical subwoofers can be a problem solver and will create a smoother sound in any room. Some rooms might need more than two subwoofers for the best sound quality.

The bass is the only part of the musical spectrum that has this problem: the lower the frequency, the longer the wave. The sound waves for deep bass are many feet long. Mid-range and high frequencies waves have very short waves and don’t have this issue.

Designing and installing a home theater system, particularly the audio part of the set-up, is as much an art as it is science. We have years of experience creating systems in a wide variety of rooms and will work with you to design the right system for your home theater or media room.

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