Bottoms Up Take the subway long enough, and you'll come across just about every kind of person there is. Write about subwoofers long enough, and you'll experience every kind of bass performance at just about every price. So how did these pairs of subs from Infinity, M&K, Polk, and Velodyne fare?

Two of the four subs in the lower price tier -- the Polk PSW250 and the M&K K-9 -- have such limited output at the lowest frequencies that they're arguably not subwoofers at all. But both are excellent woofers with distinct advantages: the Polk costs only $300, and the $550 K-9 is about the size of a bread box. If you're short on either cash or space, and don't demand the loudest and deepest bass, one or the other could be right for your home theater.

On the other hand, the two remaining entry-level subs -- Velodyne's $549 VLF-810 and Infinity's $499 Interlude IL 100s -- do qualify as true subwoofers because they can play down to 20 Hz with low distortion, albeit at lower SPL levels when compared with their big brothers. But even here, the Interlude managed to hit a very respectable 79 dB SPL -- and it's one of the best looking subs in the lot.

Stepping up to the subwoofers in our higher price tier gets you bass that is louder and, in some cases, lower. All four models -- the Polk PSW650 ($770), Velodyne's SPL-1200 ($1,399), the Infinity Intermezzo 1.2s ($1,800), and M&K's MX-125 Mk II ($1,199) -- hit average SPLs in the 25- to 62-Hz range that exceeded 105 dB, which means they're capable of producing bass that's as loud as what you get at your local movie theater! And if you're looking for a relative bargain, Polk's PSW650 costs $430 less than the next sub in the bunch. (That its amplifier is rated at only 165 watts, while the Intermezzo 1.2s and SPL-1200 are rated at 750 and 850 watts, respectively, only shows that amp specs often have little to do with subwoofer performance.)

If the very deepest, subterranean bass is what you crave, then you'll have to turn to the most expensive subwoofers in this group -- the Infinity Intermezzo 1.2s and the Velodyne SPL-1200. Both can reach all the way down to a bone-rattling 16 Hz, performance that will have you running for cover the next time you pop End of Days or The Matrix into your DVD player. And while the Velodyne was able to play slightly louder than the Infinity in the critical range where you'll find most bass, at 16 Hz the Infinity was able to outrumble the Velodyne by a healthy 7 dB. Now that's a subwoofer!

Fast Facts In The Lab