@rand-11 - yeah, totally understand. It's not a tuned basstrap. However, the 703 FRK is not a tuned bass trap either. I'm just trying to say that there's some element of more efficient bass absorption when you place a flexible reflective material in front of a highly absorbive material (i.e. the 703 FRK). It's not going to be perfect and it's not going to be a "tuned bass trap", but I would error on the side that there may be some benefit to the leather couch over the cloth couch. :)