The OHM Micro Subwoofer 12 is a self-powered unit that takes the amp output and crosses it over internally. There are choices of cross-over points and a volume control. Since I first installed it, I have turned the volume down slightly as my wife was complaining about the whole house shaking. Actually, it does sound better turned down a bit.
If I had a sub-out on my Schiit tube pre-amp, I could have used that, but it sounds fine as is. I am using a Parasound HCA1500 to power the system.
If I had a sub-out on my Schiit tube pre-amp, I could have used that, but it sounds fine as is. I am using a Parasound HCA1500 to power the system.