Recommendation for connecting SUB Woofer?

Hi Naim Community,

My system are like below.

Naim NAP250/ NAP180(not used) / NAC82/ NDX2 / Hi-caps/ XPS
Speaker : Rogers LS5/9

I’m very happy to get nap250 and it’s very nice to feeling

However additionally thinking about purchasing the REL T5X subwoofer. (My room size is 4m X 6m)

  1. Do you recommend using the NAP180 as a high-level input terminal for the REL T5X?

Nap 180 would be connecting with hicap port 2
(currently use Port 4: NAC82 , port 3 : NAP250)

  1. Or do you recommend using the ndx output as a din + RCA for thinking VFM…(?)
    RCA ports to use the low level inputs
    (din: Nac82 / RCA: REL)

Has anyone tried the method as #1 ?



Many have to their great satisfaction. Better when connected at the speaker end of the speaker cables.

Hi there, I have never connected a sub to a Naim amp but I do have a REL connected to my power amp and the best method by far is via the speaker terminals. This is very much what sets REL Subs apart from other Subs as this method will provide a much better integration with your speakers as being fed the exact same output. Once you have adjusted the gain, volume level and correct phase you should struggle to know where the extra low end is coming from your sub or your speakers, if the sub stands out, you need to adjust your settings. For low end sound this is non directional so I do not believe the theory of needing 2 subs, I have one and you wouldn’t know if this was placed left of right with your eyes closed, well worth the effort if you can get it right. You will need patience and I would also suggest a system set up disc/download, I used a Nordost disc which I found to be the most help to tweak to my satisfaction.

I’d go further - for me it sounds like the bass is produced by my SBLs, and so just does what the stereo recording suggests it should. Also I get a more complete and focused sound stage.

@NicolasLian - Even instruments you don’t associate with lower frequencies sound sharper. I know it’s a trick of my hearing but I’m very happy. That’s with one. I’m willing to try two at some point but I have the crossover frequency right down and the gain right down. I also found the phase worked better at 180 rather than zero.

+1 for the direct to speaker connection method. I’ve tried my Rel sub direct from the pre-out from a supernait 3 previously and really didn’t like the results so gave up quickly. Once I’d connected spades to the high level lead and hooked it up I spent no more than 15 minutes fiddling with phase, volume and roll-off frequency to really great effect. As others have said, once it’s dialled in correctly your ears will know and perhaps like me you’ll be astonished by all of the unexpected benefits to everything else as well as lower register bass. Good luck and from my experience I’d go straight to the speaker connection via high-level cable.

Very good point, good subwoofers don’t just improve the lower end, the whole soundstage will improve. I also use Super tweeters and again, these do not just improve higher frequencies, in particular the midrange improves immensely.

HI - I’m also looking at trying a Rel t5x - single sub - and from my Googling I can’t work out how to attach via speakers with the supplied lead which seems to be designed to go to an amplifier or to a single speaker. Do you need to have a lead specially made up that is long enough to split to both speakers?
Thanks very much.

You only attach the sub to one speaker. I think things would get rather hairy if you tried to attach to both.

This is the weakness (in my view) of having a single sub for playing music - you only extend the sound of one of your loudspeakers.

You can do this a few different ways. With a Naim amp it’s best to connect to the speaker input terminals rather than the power amp output. To do this you need to split the outer sheath of the supplied cable so that you can reach both speakers. Alternatively get a split cable made up if you don’t want to take a knife to the supplied cable.

An alternative is to use a special cable that allows you to connect to a Naim power amp without upsetting it. Rel make such a cable, but theirs is very expensive. A cable supplier called Designacable make a much cheaper version. These cables have ‘piggyback’ banana plugs which you plug into the amp, then you plug the main cables into the back of these plugs. Non-Naim amps generally don’t need this slightly unusual arrangement.

Finally, you can use a low level connection from your preamp. Rel recommend that you don’t do this if you want the best possible performance, and I would agree with them, but it works.

I can only talk in general terms here but I have never connected a sub to my loudspeakers. I have a REL Sub and the recommended way to connect is via the speakers terminals on your amplifier, this is known as a high level connection and sets REL apart from some of he other sub brands. . If connected and tuned in correctly the sound should not feel like it coming from left or right, low frequency sounds are non directional.

What a high level connection means is that you’re actually taking the output signal from the same amplifier terminals that feed your main loudspeakers and you’re feeding that forward, in our case into the Rel.
Hope this helps

That’s not correct. You split the cable and connect to both speakers. Otherwise you only get bass from one channel.

Yes, apologies to everyone. I’ve obviously misremembered how it’s done.

Thanks all - going to take the plunge and try splitting the outer sheath on the supplied lead.

Hi @NicolasLian
I use the Graham Audio LS5/9 in a room the same size as yours, and I use their passive subs, SUB3.