Hi,
The sub in question can be viewed here: link Go to page 20
Look at diagram #2.
There is no way to run both left and right via RCAs to the sub. I
can run the left and right via high level. I really don't think
it matters that both left and right are fed to the sub. I did try
a "y" connector to run both left and right to the one input, all that
did was put my entire system in mono!! Bass in the sub levels are
mono (Flame me!!!) [] . I have the sub set to the lowest
possible freq. setting and the "volume" on the sub set to #1.5
My speakers are Mirage m-290s (1992). They have 6.5" drivers, I
bought the sub in 1993 to ofcourse add bass. I was powering all
of that with a NAD 701 receiver (25x2). Last fall I cooked
the receiver so I bought a NAD 272 power amp (150x2) and am using the
701 as a pre/tuner. With the addition of the 272 I really don't
need the sub due to the massive bass provided by the NAD 272. I'm
so impressed with the 272 next month I will buy the NAD 162 pre amp and
use the 701 as a tuner only. Then replace my speakers with maybe
the Monitor Audio RS8s. I know this is the Klipsch forum, but in
my area there are no Klipsch dealers.