How to set up REL Subwoofer?

I don't know. Best to contact Sumiko or REL direct.

Have Bel Canto 500m amps and getting the Rel R 205 sub.

Any problems to hook this sub up to class D amps?

Similar question. Just got T9 to use with 7.1 ht with triad gold monitors for front 3 channels. If I want to use high pass do I need a dedicated channel from my Cary 7 channel amp or do I piggyback on another channel

If you want to use High-Pass you should wire the speakon connector to the front L & R speaker posts. This will send the exact same signal to both the main speakers and the sub. Since both receive the same signal at the same instant in time, there is no phase loss as there is whenever the signal is sent to any additional processor - such as your receiver. If your Cary processor is setup as most 'n.1 or n.2' processors, then you have probably identified the front speakers as 'small' to indicate that you want all low frequency content directed instead to the processor tonvert it into a stream to output to the subwoofer output jack. This means that technically, you would have a superior signal path that preserves precious phase and time values but your sub would rarely or never see anything to play.

The only time it makes sense to choose to wire your sub to the binding posts of the amp is when you have all the signal going to the amplifier and the system has high enough resolution that phase distortion is audible.

Hi!
I just purchased a used REL Q150E sub without the high level Neutrik Speakon cable.   Anybody have one for sale?  
OR
information on
1) which model Neutrik Speakon connector to buythe correct wiring diagram and...
2) wiring diagram
Thanks people!!