Hi basically I am converting my Bedroom into a small personal Cinema, it it a small room cinema it is 10.5 ft by 10.5 ft by 7 ft in size. I am bulding the sound system slowly but the the moment I use Mission M73 floorstanding mains and have a fairly nice Denon amplifer to power them. The main problem is that the treble has a twang sound to it both on DVD's and 2 channel music. If I clap my hand in the room I get a nasty hi pitch twanging sound. The if I rememmber correctly the room had some work done to it about 5 years ago extra plasterboard with a reflective rear metal like substance on the back (Like Kitchen foil) was built up over the top of the prevous walls of the room. I was wondering if some sort of Treatment, cloth or curtains could be used to tame my treble colouration. Can anyone help me?