Sub Woofer hook up with McIntosh MC 501

I already run xlr's to the input on the amp for the pre-amp you can only run one input line, the mac is switchable between xlr and rca this allows you to run only one input at a time.

Active subwoofers accept line-level inputs so you could run the connections from your preamp instead of your amps. If you insist on passive subs, you may need another amp just for them.

I have also heard of people running a sub off the speakers. I am not sure what that would do to the amplifier load however...not that 501s would really notice if the connection is in parallel but... Personally, I wouldn't go with this option.

Arthur

If only one set of outputs at a time are valid with your preamp you could change your preamp, or get a Y-Cable that plugs into your preamp or get a custom Y cable (my friend had this option done so he could biamp with 2 amplifiers) if you using RCA's Monster makes a single solid 1 into 2 adpaters (audio advisor sells them) I use to use these so I could run my single sub output to two subs.

I would not try running both off your amp.. only bad things could happen..

Aball
Are you suggesting running a sub off the speakers will do damage? I don't understand where you are going with this.

Has anyone setup their sub to run from your speakers?

Yes Mitch, I think it "could" do damage in certain circumstances. It is all a matter of parallel or series circuits. In the former, you get a big drop in load impedance for the amp. In the latter, you get current sharing issues which can be quite complicated.

I forget where I read about doing it that way - I think it was a thread right here on Agon some time back. Maybe someone who has done it can chime in.