REL Subwoofer Naim NAIT 5

I have purchased a REL Sub. I get a hum when i hook it up. I am attaching it to the amp speaker post along with the speaker cable.

Not sure what to do.

You shouldn’t connect directly to the back of the NAIT 5. It will need to be connected from the connectors on the speakers.


Richard, this was taken from my REL Stampede sub manual and seems to contradict your advice. Can you explain why?

Connection to right and left speaker using the high level neutrik cable

Yes, the usual REL recommended power amp output connection can upset Naim amps, so for these it’s best to connect at the speaker end, that way the extra cabling is not “seen” by the power amp and it should be happier.

In order to do this at the speaker end you need to split the Neutrik cable or buy a custom cable, as it will run two wires to one speaker, and one to the other speaker. Depending on the length and type of speaker cables you use, this may be worth trying, although I’m not sure it will affect your hum problem.

Is it the sub humming? After updating connections following Richard’s advice previous, read this:

Does this include the Nova?

@Kellynaim - Is it the sub humming or are you getting a hum through the main speakers too ? Is the sub only connected to your Naim system ?

Amp or speaker end connections aside, a simple thing to try is changing the signal ground switch on your NDX first. Looking at your system profile I suspect it’s set to chassis. Try floating. Does it affect the hum ?

A member who was having noise and performance issues with a REL and their Nait 5i reported that the issues were cured and sound quality greatly improved once they moved to the Naim-preferred connection at the loudspeaker end, so the Nova may well be similar in this regard.

My REL only has a single input at low level and the Nova has 2 outputs. What cable would you recommend for this?
I might add it’s not really practical the other way.


If it only takes a low level (pre-amp level) input the you’ll likely be fine straight from the Nova - there is a dedicated pre-amp/sub output on RCA Phonos. I would recommend a low capacitance cable.

Would this be mono to mono or mono to stereo type?

It should be a stereo connection, taking L + R channels to the Subwoofer.

Only a .5 LFE connection from a HT processor will be a mono type.

Thanks for all the helpful advice. I did change the ground on the ndx, and voilé, hum ceased.

I also changed the location of the Rel connection. At the speaker end, the sound is much better. I only connected the left speaker to the Rel, as i dont want to damage that cable with the sick connector.

As it turns out connecting speaker side to the rel sounds a lot better than i thought. More integrated, more musical.

The NAIT 5, a fine amp, btw, gets smoking hot when connected at the amp end. Do not connect a NAIT 5 to a REL at the amp end, which is exactly what a REL support engineer said to do. Do not rely on REL to be a “Naim Whisperer.”

Thanks to all who stepped up.

1 Like

You really need to use the high level input with a stereo amp. The single low level input is intended to take a mono low frequency signal from the LFE output of an AV amp.

My test music was the new Deutche Gramm. JS Bach Toccata and Fugué. Its like being in a cathedral. Wow NAIM/REL.

I also ran the remaster of Behind Blue Eyes, and Bill Evans with Red Mitchell on the bass. (Red was the bassists’ bassist during the jazz era).

I think im going to buy another cable from Rel to get both sides hooked up. That way, if i wreck it while taking it apart, ill still have the original.

Lastly, i use a pair of original KEF 101 Reference speakers, built in 1983.

They still sound amazing. For speaker stands, I put them on stacked cinder blocks, which is kind of college retro, but very stable.

Bear in mind you are only getting half the bass. You really should connect to both speakers if you want to maximise the effectiveness of the sub.

I know. If REL did not use that connecter, it would already be done.

All good then. I’m pleased you are well on the way to sorting it out.