How to add a ground connector to my BHK 250

I just got two REL S/510. When I connect them the correct way, I hear a VERY loud huuumee.
This is a known issue and can be fixed with connecting the black wire from the REL sub to ground on the amp,
As I understand it, newer models of the BHK 250 has a grounding post.

How can I add a grounding post to my BHK? Can you answer that @Paul ?
I really need to fix itbefore I can use the subs.

The subs are also connected to my AV receiver using LFE.1 RCA.

Found this picture of a chassis ground terminal. I want one :blush:

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I called PSA and they sent me a pair.

How did you mount them?

I’ve since sold my BHK250 but as I recall it was just a matter of screwing them into previously threaded/tapped screw holes. It came with directions, a super easy install.

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Great thread! Put me in line for a pair also! @jamesh can you help us out?

@Martin-Andersen and @paul172 shoot me a quick email and I can get them sent out to you.


Special shout out to @jamesh and PS Audio for getting these out to me asap! Great customer service!


Slick, I’m jazzed we got it to you so quickly. Any chance you could post a picture with the instructions? I got a request from someone up here to post but I don’t have an easy way to post them.

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Waiting for my ground post from PS Audio.
The ground post will only help with hum when the amp is on.

To remove the hum when the amp is in standby mode, you need two special Y-cables from REL.
I am going to make them myself.

You need 4 1K ohm resistors and some connectors for the ground post and speaker terminals.

It’s going to be very crowded on the back of the amp.
From the REL sub, yellow+red twisted goes to the plus terminal. black goes to the ground post.
The REL Y-cable. Attached to the ground. Then the two ends with the 1 Kohm goes to the plus and minus speaker terminals. Se attached picture

does anyone else have a new bhk 250 with what looks like a grounding lug/post installed? I am not even sure that’s what it is. nothing in any of the manuals about it…

Hi you don’t need to use it. It was added to avoid hum when connecting REL subs with high level input

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It’s to help with connecting REL subwoofers. Because the BHK has a balanced output and because REL (and us) recommend using the high level input on the REL, which comes from the speaker outputs of the BHK, this is how you ground the REL.


thanks, i have a rel s/510 so that’s what i needed to know