I have a Harman Kardon 75+ quad receiver. I've got a turntable and a Panasonic RS-845 quad 8-track tape player hooked up to it. The amplifier has a mode selection switch which includes the options mono, stereo, SQ matrix 1, SQ matrix 2, enhanced stereo 4-ch discrete. I'm basing this discussion on the Columbia SQ lp and quad 8-track tape version of the Broadway revival cast recording of "No, No, Nanette" (1971). When I listen to the 8-track tape using the 4-ch discrete mode, the mix is fantastic. On numbers with the chorus, the voices come from the back channels and don't exist on the front channels. The tap dancing goes from front left to front right to rear right to rear left. It's incredible to listen to. When I listen to the SQ lp using either one of the SQ matrix modes, the back channels seem to exist only to provide a kind of theatre sound effect. There isn't any remarkable front/back separation. I'm new to quad. I've always been interested in it but never had the time or money. I decided to start out with quad 8-track tapes - but the selection is very limited and, many times, lp tracks were left off for space reasons. In the last few weeks, I decided to try out a few lps - starting with SQ lps because it's less complicated to get going with. I know this is old technology, but does anyone out there have any words of wisdom regarding whether or not SQ lps did not produce the same effects as their quad 8-track tape counterparts? Could it be that something is wrong with the SQ matrix functionality of my receiver?