Connecting single sub to monoblocks


I have the BHK pre and M1200s, also a single REL sub.

Can I use the high-level input to connect the REL given there’s no common ground? (REL I think advises against it).

I’ve looked but not found this answered anywhere else, apologies if I’ve missed it.

Very Best!

I had this issue when I went from a stereo amp to pair of mono blocks.
Rel advised me quite clearly that you need two Rel subs for mono blocks, one for each amp.
So I had to purchase another Rel sub.
I initially got a S3 but have since upgraded to a S/812.

Thanks sherifd2… But actually, just come across this.

Suggesting earth lift on class D, i.e. don’t connector the ground, and let the rel use it’s own ground as the reference.

If that’s the case I have no issue right? And no danger of hum.

Am I reading this right? Sounds like the answer I need.


Yes, you can hook it up like this with no problem. If you do get hum, you can either hook up a single ended cable like they recommend in that link, or you can connect the black to the M1200’s ground post.

:+1: all working nicely single ended.

Thanks James.

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