Every day it's the same: You stand on the same subway platform, at the same time, looking at the same cluster of fellow commuters, all of you waiting to begin the long trek home. But as you feel the concrete platform begin to rumble and see the headlight play along the tunnel wall, you suddenly imagine the train careening wildly into the station and -- brakes screaming, sparks flying -- coming to a halt. Everyone else on the platform hits the deck as a blaze of gunfire erupts from the train's shattered windows. And then the doors fly open and the arch villain strides out, ready to take you on in the final confrontation. Suddenly, the commute doesn't seem so dull.

Once at home, still in your daydream's grip, you pop End of Days into your DVD player and jump to the scene where the subway train, engulfed in flames, comes flying through the tunnel. But your home theater system isn't even giving you the rumble of the real subway, let alone the slam of a train out of control. It all seems flat and distant, and you find yourself faced with the fact that your system just can't keep pace with either the movie or reality.

It's time to buy a subwoofer. True, many CDs and DVDs don't have much going on at the bottom end (below 50 Hz or so), so a sub might seem like an audiophile indulgence. But more and more discs -- especially DVDs -- exploit what lies beneath, and the big blockbuster films almost always do. So getting a first-rate subwoofer isn't a matter of keeping up with the home theater Joneses -- it's about experiencing all the fullness and depth movie soundtracks and music have to give.

And there are more mundane reasons for thinking about adding a sub to your speaker array. The best locations for reproducing bass aren't the same as for higher frequencies. While you should keep your front speakers away from the front and side walls of the room, and your surrounds high on the side or back walls, subs belong on the floor -- and usually work best tucked into a corner. But a sub's optimal position isn't as fixed as those for your other speakers, and thanks to that flexibility, adding a subwoofer can be the single easiest way to improve your system's overall sound.

The roundup that follows is similar to last year's "Bargain Bassment" (May 2000), which looked at five $500 subs, but with a new wrinkle. Rather than focus on subs that sell for the same price, I gave a thorough thrashing to eight models from four manufacturers. Each company submitted a budget sub as well as a second, higher-price model so we could get a handle on what you get from a subwoofer when you move up the price scale.

Infinity gives us the biggest price spread with the $499 Interlude IL 100s and the $1,800 Intermezzo 1.2s. On the other hand, only $470 separates Polk Audio's PSW250 ($300) and PSW650 ($770). The M&K K-9 and Velodyne VLF-810 both go for $550, while M&K's MX-125 Mk II goes for $1,199 and Velodyne's SPL-1200 is a cool $1,399. But more money doesn't necessarily buy you subwoofer happiness. As we'll see, there are a lot of other factors that go into determining which sub's right for you -- like performance (see "In the Lab," pages 80-81, for my measurements, including graphs of each sub's maximum output).