which sub to add to vandy 1C's

Looking to add a little tightness and speed to the bass on my vandys, it seems a tad too laid back for me on certain rock recordings. Of course I want it to integrate well with my current setup (nad 320bee and vandy 1Cs). would love to get the a 2WQ but unfortunately its a little out of my price range. I want to spend $300-$500. room dimensions are fairly small so i don't nessesarily need the most powerful sub. I've considered upgrading to the 2Cs but think adding a sub makes more sense as i am completely satisfied with the highs, mids, soundstage of the 1Cs, especially on jazz and more accoustic recordings, just missing that extra punch that i think a sub would provide. thanks.
I agree with you re: the price of the 2Wq, although it is an excellent subwoofer.

In your price range I've heard very good things about Monitor Audio's subs. They may cost a slight bit more than $500, but are probably your best bet in the price range.

BTW-- the NAD/Vandy is an excellent combination. I hope you're enjoying it.
Thanks for the response. It sounds like the monitors may be right up my alley from what i've read, fast and tight. I will have to audition them soon. To answer your question, I extremely pleased with the Vandersteen/Nad combo. They sound like they were made for each other. As a relative novice, its hard to imagine a better sounding system for the grand I paid. This system absolutely breathes life into the recordings. Thats the only way i know how to describe the sound.
I'm not going to argue-- it does breathe life into recordings. It was the system that I first auditioned when I started thinking about buying a stereo. I only went with the polks because of the amazing deal my wife gets at work (60% off). As soon as I have a stable job (just graduated from college, still unemployed) I plan on switching out my Polks for Vandies.