SVS or Velodyne

Neither- get a REL !

I have had Velodyne DD-15's for years. They have an on board EQ that shows you exactly what is going on in the room. The setup is not very difficult and makes the subs disappear. I have them set to 3 out of 100 on the volume. The biggest problem with subs is that people tend to crank them up too much.

Tim

I have a Rythmic 15" in a custom cabinet built by Salk Sound. Great, super tight base that really digs deep. Of course the cabinet is probably a 30" cube made from 1" MDF with enough bracing inside so you can set a turntable on top it and never skip. Weighs about 220 lbs too. Nobody ever accused Jim of cutting any corners building speaker cabinets. 

Those Salk built Rythmiks are great. You can also buy the DIY F15 kit and build an enclosure yourself, bracing the hell out of it as does Jim. The Salk wood finishes are really beautiful.

I thoroughly enjoyed my SVS’ for home theatre effects.I stopped using them with music I wasn’t happy with there performance. Rythmik gets a big yes from me.