OTHER TECH

Adding a second sub can give you more even bass over a larger area. THX recommends placing the subs across from each other, in the middle of each wall. Using four subs can give you more even bass over a much larger area than one or two subs can. It's best to place a sub in the middle of each of the four walls. But if a door or other obstruction prevents this, you can place them in the corners.

Maybe you've heard of somebody adding a second subwooer to his home theater for whatever reason. You might have even heard of somebody with these subs. But FOUR?

Before I get to the technical arguments for four subs, consider the practical side. With prices continuing to drop, manufacturing quality on the rise, and high-performance subs getting ever smaller, you can now get multiple subwoofers for what you used to pay for one first-rate model. So why would you want to add more subs? The answer lies in the way we now use our audio systems.

As we've become addicted to giant HDTV screens and surround sound for films and music, our houses have become the movie palaces of old. The days of listening to monolithic stereo speakers from a single perfect position are gone. As a good host, we now have to be concerned about the sound quality at a number of seating locations for family and friends who drop by to see the latest flick. Multiple subwoofers, properly placed, can help address the sound-quality issue by producing uniform deep bass across a large listening area.

In my house, we have a traditional Sunday-night gathering in our theater. (Being in the A/V industry has its benefits, since I have to test the latest equipment somewhere.) When I added a second sub to the theater, my family was very impressed and remarked on the great sound. I neglected to tell them that they were the only beneficiaries of the upgrade, since the sound had always been that good at my seat.

About a month after that, I was at my friend's house, and he couldn't wait to show me his latest addition: a second subwoofer! He placed the shiny new $500 compact sub right next to the original one (a $99 special) and proceeded to crank them both up and smile. As you can imagine, it sounded like the latest incarnation from the local car-audio emporium. After my hearing came back, I unplugged the old sub and repositioned the new one. Unfortunately, I wasn't able to set him up with dual subwoofers, but the new unit sounded remarkably better.