Hello guys
I have recently purchased Marantz pm5004 with Q acoustics concept 20. Both of them support Bi Amping
A small clarification ... your speakers will support bi-amping but not your amplifier ... If your amp has A & B speaker outputs and if you are trying to use the speaker A output to the "Tweeters" and the speaker B ouput to the "MidWoofer" ... OR ... if you are connecting two pairs of cable to the speaker A output and if you connect the "Tweeters" and the "MidWoofer" separately on the speaker end then ...that method is called "bi-wiring" and not bi-amping. For a precise/correct bi-amping you need a preamp and two identical power amps (total 3 units setup)
Well if you want to use your PM5004 for bi-amping then there are two prerequisites ....
1. Your PM5004 amp should have preamp outputs ... If it is not there then bi-amping configuration is ruled out.
2. If preamp outputs are there, then you need to buy a power amp of similar wattage as your PM5004.
Connections ....
1. Remove the tweeter & midwoofer shorting clamps on the speakers.
2. Ignore speaker B outputs in your PM5004 ... Connect a pair of cable to the speaker A outputs L+R and connect the other ends of the cable to the speaker's "Tweeter" inputs (the upper ones on the speakers) ... Left ouput to the left speaker and the right output to the right speaker
3. Use a pair of 2 RCA cable and connect the preamp outputs of your PM5004 and the preamp inputs of your power amp
4. Connect a pair of cable to the speaker outputs L+R of your poweramp and connect the other ends of the cable to the speaker's "MidWoofer" inputs (the lower ones on the speaker) ... Left ouput from the poweramp to the left speaker and the right output from the poweramp to the right speaker ...

start enjoying your setup
Hope this helps ... Cheers