The reason I want to use the low level input is that I get a weird problem when I use the high level input. I get mad fluttering of the subwoofer when I play a record.. This doesn't happen with any other source. I know, immediately you would think that it's a turntable isolation problem but it's not. The problem has disappeared when I connect the sub via it's low level input and my phono preamp has a subsonic filter (IEC equalization) which is turned on.
So I have a couple of options:
1. Use the low level input (not really recommended by REL)
2. Use the high level inputs and turn the sub off when I listen to records
There is a long thread in the Steve Hoffman forums started by someone with nearly the exact same problem. He spent a year and a half trying to sort it out and eventually just ended up getting a different turntable. https://forums.stevehoffman.tv/threads/my-subwoofer-hates-my-turntable.405112/
It's a frustrating problem.