Elizabeth is correct. I had a 4BST powering Thiel CS7s for a short time and, at moderate volumes, it could not handle the 2 Ohm dips and would go into the red and then one channel would typically shut down from thermal overload. Upgrading to 7BSTs helped for awhile until I started blowing tweeters from underpowering them with the Brystons. It took Krell to solve my amp problems with such demanding loads. Bryston makes good gear, it's just that they are not a sub 4 Ohm capable design.
