I have an old Pioneer VSX-453 Dolby Surround receiver. I just
purchased a new Paradigm PDR-10 subwoofer to complete my surround
sound setup. Unfortunately I've lost the owner's manual for the
receiver and I don't know the best way to connect the sub to the
receiver.

There is an RCA-type output on the back of the receiver that says,
"Center Amp Pre Out". The sub has a "Low-Level Input" with an
RCA-type plug. Because I don't have the receiver manual and don't
know exactly what the "Center Amp Pre Out" is, I hesitate to try to
hook it up this way 'just to see' for fear that I may damage
something. Any suggestions on this method?

The other option I realize I have is to use the "Speaker-Level Input"
on the sub and connect it to the "B" speakers on the receiver.
However, when I do this and have both "A" and "B" speakers on, the "A"
speakers become very quiet, almost as if they're not there at all.

Any suggestions would be greatly appreciated. If anyone knows where I
can find a copy of an owner's manual online for the Pioneer VSX-453,
that might also be helpful.

Thanks in advance.