There’s a Q control knob so you can adjust a bit. I had to adjust that on my VTF2 mk5 pair to get it right so long listening sessions were good. It’s also important that the room has carpet or at least area rugs.\n\nThere’s a CD with low test frequencies and songs that HSU includes with each sub.\n\n\nThis is helpful. My living room is entirely carpeted and has quite a bit of furniture to help reduce reverb.\n\nHave you compared your VTFs to the ULSs? If so, what differences\/similarities did you note?