Steinmusic Acoustic Discs

I bought a set of 3. I placed one on top of each speaker, centered from side-to-side with the puck edge one inch from the back of the speaker. The third puck I attached to the ceiling, centered between the speakers and centered between my listening position and the speakers. What I heard was a bit startling. Another reviewer said it was like hearing a wall of sound, and I agree. To my ears, the pucks also made my speakers disappear better. Very enjoyable, and worth the money, in my opinion.