In the past, I have owned a couple of equalizers which I played around with for pretty much a strictly two-channel application. Unless you had one of the "ultra-expensive" Audio Control units, placing one of these in the "chain" and using the sliders for adjustments, usually added a considerable amount of "noise" in to the equation which, by today's standards, would be unacceptable.
Since much more sophisticated and flexible systems are built in to most of today's AVR's and Pre-Pros and unless it is one of the current bass EQ systems such as the Velodyne(SMS-1) or SVS(Audessey), obviously the need for any external equalizers has disappeared and nobody seems to be making them anymore.
