Just purchased a pair of SVS-SB-4000 subs to supplement the bass in my Matin Logan 11A impressions hybrid speaker. The subs are excellent and they add deep controlled bass to the sound. I crossover at 60 and volume is at 5. These settings work well for me. The built in amps are 1200 watts each. The Rel I was looking at had 300 watts. I have found that having extra power in reserves helps loudspeakers as well as subs really open up. Also, before I purchased the SVS I called SVS and we spent a considerable amount of time reviewing my system and how I could maximize my sound. SVS was very knowledgeable an helpful. They were easy to reach via phone. Hope this is helpful.