Kef KC62 and M700 high level hookup

Trying out a KEF KC62 subwoofer with my system.

Could easily connect it low level to my BHK preamp RCA’s.
But would prefer to connect it using the high level input to the M700 mono’s.

I am aware the M700 are tricky to connect a sub to

Anyone have any recommendation to make that possible without making smoke come out of the amps ?

The KC62’s owner manual doesn’t address the issue of high level connection to amps that don’t ground at the negative speaker terminal. Their website’s instruction page https://uk.kef.com/blogs/news/simple-subwoofer-connection-tips doesn’t address the connection issues to differentially balanced amps either. With REL subs, you just don’t connect the wire that usually goes to ground and only connect the two positive terminal connecting wires. You would need to contact KEF directly to see if that would work or if you must use one of the other three methods with balanced amps.

You need to connect the negative terminal on the amp end to an alternative grounding point same as with any Class D amp.

NAD c298 has a ground lug that may be utilized

Return the m700 with Ps audio’s liberal return policy, and get a pair of NAD c298’s