Home Theater Hacks

Hack #53. Use Multiple Subwoofers

As the size of your theater room grows (along with your budget), you might want to add a second subwoofer to really rattle your windows. However, you'll need to take great care in placing the second subwoofer so that it helps your sound rather than hurts it.

If you get a good subwoofer [Hack #49] , you're going to end up with a solid bass response from your home theater, even if you don't spend a lot of time figuring out the best location for the sub [Hack #52] . A great sub in a poor location still is going to provide a good low end for movie playback. However, when you begin to use a second subwoofer, placement of the second sub becomes critical. You actually can knock out a lot of your bass response with a second subwoofer if you're not careful.

First, forget about all those old web pages or drawings of a room with a subwoofer on different sides of a room or on either side of a couch. More often than not, these were done by people who were not audio enthusiasts.

The problem with multiple subwoofers (and many of those drawings you've seen) is wave interactions. Have you ever dribbled water from the kitchen faucet into a pan of water? Try it and notice how the ripples expand out and reflect off the sides of the pan. This is almost exactly how sound waves travel in your room from your subwoofer. Now start to dribble more water, from another glass, into a different location in the pan. The waves from the two sources of water are now interacting ...