Hsu subs

I purchased one of the 1220 Hsu Research amps as part of my Home theater setup. It is matched with sunfire amps and M&K s150 and ss150 speakers. I am extremely pleased with the response that I get. My system is used about 95% for movies but the little music that I do play through it also sounds very nice. This even though the M&K's are not the best musical speakers that you can get. I also went up and met Dr. Hsu at his office and had a chance to speak with him and some of the members of his staff and found them all very friendly and helpful. I have no regrets with my purchase but am thinking of adding another even though this one will shake all of my pictures from the wall when turned up.

There is a long list of reviews on the HSU 1220 and 1225 at Audioreview.com

I've had a Hsu 12va for 2 1/2 yrs, and I don't honestly know why I would ever part with it. They make a very nice product.

The Hsu amps have an equalization circuit in them that boosts peaking at about 19 hz and then cutting off at the low end. Essentially, the Hsu's are detuned a half octave lower than a true fourth order and then the boost brings them to flat down below 20 hz. The nice part of this is that in the range of boost, the port is radiating all the energy while the cone is not moving much (port resonance). Thus, the distortion remains very low

I use 2 TN1220HO subs & Hsu's Model 500 Subwoofer Amp crossed at 51 Hz to augment the low end of my Magnepan 3.5R speakers. For 95% of the music I have listened to, the 1220's blend into the speakers seemlessly; the 1220's are very clean sounding and powerful, but not boomy, and I have had no need to turn the dial on the sub amp past the 9 o'clock postion; I have listened to a home theater system pairing Velodyne's top-of-the-line 18-inch subwoofer with MG 3.5Rs, but the Velodyne's boomy sound muddied and ruined the sound coming from the speakers; If you just want to shake the building, go with something like Velodyne, but for reference-quality bass extension, I find the TN1220HO subs worthwhile.