Subwoofer meshes well with 2-channel?

Many current subwoofers work VERY well with a 2-channel system. One of the advantages to using subs is that they relieve the drivers in the main speakers from having to reproduce the very low frequencies. Many listeners find that their systems not only reproduce low frequency sounds better, but that mid-range clarity and transient response are improved as well. One of the better subwoofers that integrates very well with a 2-channel system used mainly for music is the Vandersteen 2wQ. I have two of them in my system, and they virtually disappear into the music. You should obviously look at as many subs as possible that fit into your budget, but I do urge you to listen to the Vandy 2Wq's.

Apache1 may be correct about the Vandy 2wQ's in your system, but let me add two points that I should have stated in my initial post.
1. A pair of subs is much preferable to a single sub. Having two subs reduces or largely cancels out room nodes that may reduce the audible bass response.
2. The low frequency response you actually achieve in your listening room is going to depend to a significant degree on the acoustics of the room itself. Many people who add subs to their systems often find that "fine-tuning" the room (with furniture placement, sound treatment, etc.) is necessary.

What I can add about the 2wQ's is that I often play organ recordings and my 2wQ's reproduce frequencies into the low 20-Hz range. They also do a good job with low-frequency sound effects, although they lack the "slam" and dynamic headroom of some of the best subs (such as Velodyne, BagEnd, etc.).