** This Ad is Marked as SOLD by seller and cannot be responded to. **
The Hallographs reduce the audibility of the chaotic reflections from the walls of the listening room so they don't overpower and interfere with the direct sound from the speakers. Effective location will vary with the acoustics of one's listening room, but a good starting point are the corners of the room behind and to the outside of your speakers. What we hear in our listening room is better presentation of the soundstage and increased clarity/transparency of the music.
My wife and I have used these to improve the acoustics of our listening room over the past 8 years. They really do make a difference for us in our room. You can see them positioned in the full room photo.
We are only selling them now because we are downsizing and we will be transitioning to headphones listening with no speakers. In connection with our downsizing, all of our audio gear has been listed for sale so please take a look at my other ads posted on AudioMart.