Does a Powered Sub need a Preamp?

Installation requires line-level outputs to preamp.

Additional information can be found here:

http://www.velodyne.com/vproducts/docs/HGS_1012.pdf

It can't hurt to try it, but relevant specs that would make a definitive answer possible don't seem to be available. The required specs would be input impedance and sensitivity of the sub (which I couldn't find anywhere); and computer output voltage and output impedance (which are usually unspecified). Also, input impedance and sensitivity of the Quads (which I also couldn't find), if they would be connected in parallel with the sub inputs (as opposed to being connected to the sub's high pass outputs).

I suspect that you were planning to do this anyway, but I'll add that my guess is that your chances of success will be greatest if you connect the Quads to the sub's high pass outputs, rather than in parallel with the sub's inputs. Besides making life easier for the Quads by keeping the deep bass out of them, that will increase the load impedance (i.e., lighten the load) that has to be driven by the computer.

Regards,
-- Al

Have you made much effort on your room? Money should go on acoustic treatments before equipment upgrades, I feel.