Hsu Subs

Hi all. Which is the best Hsu sub for 2-channel music? The Hsu website claims the 1220HO is better than the STF or VTF series (I didn't see the site mention the difference between the STF and VTF series).

Also, is the 250-watt amp enough to drive any kind of music other than rap, or will I need the 500-watt amp? My monitors go down to 45hz -3dB.

I'd prefer to have a sub that has an internal amp (for space and cabling reasons) but if the 1220 is vastly superior to the internally-powered subs I'll go that route.

I've seen the recommendations on other used subs in the $500 range, but the Hsu seems to be well-regarded by a wide variety of speaker owners, whereas many of the other sub suggestions seem to be specific to speakers; that's why I've narrowed the selection to Hsu.

Thanks for your input.
A 250 watt amp is plenty.

I bought the VTF-2 for both music and movies, if I had to do it all over
again I would have bought the 1220HO - which is what Hsu recommended. I don't believe the VTF-2 is all that for music.
You might be interested to know that Outlaw Audio has a new subwoofer that they've added to their line (the LFM-1), which was designed for them by Hsu. This sub has gotten some excellent reviews, and sells for $579 (Internet direct). For more info, to Outlaw Audio's web site:
Wierd, I looked at the LFM-1 sub, the groung pin on the 3 prong input (ac power) is not there. Insto ground loop lift? Maybe I just never noticed this on other subs.

I've had the VTF-2, have VTF-3 (2x), I'd look into the 1220HO.
I have the Hsu VTF-3 Mark II and it mates well with my Dynaudio 70s, 34 Hz at -3 Db. The bass is tight and clean, down to 20 Hz. It doubles for movies, but for me, the music is much more important. It is a big box, but in Rosewood it is pretty. If I was just going to stay with stereo in a large room, I would consider the 1220 or a pair of them in each front corner. Good luck!
If all things stay the same except power it takes doubling the watts for each 3dB increase in volume.

The STFs are fixed in the max extionsion mode. The VTF's are varible thru plugging ports and flipping the equalization switch for which tuning mode you pick.