Adding a subwoofer to setup

Hi all, first time poster;

I’ve had a search and have seen some similar but not identical questions, so apologies if I’ve not looked hard enough. I lost my dad last year; he frequented these forums quite a bit and was my font of hi-fi knowledge, so I’m feeling extra lost.

I’ve got an inherited chrome bumper NAC62/Hicap/NAP140 with an LP12 / Kanns. I’d like to add a subwoofer and understand I may be able one via the 2nd or 3rd 4 pin on the Hicap. All the topics say something about the cable needing a 100 ohm resister but I’m lost on what this actually means in laymen’s terms.

Conscious I can’t post links, but I’ve found a cable with the description Naim Audiophile 4 Pin Din to Dual RCA Lead. Pre or Power Amp. Mogami 2965 Cable p/n SD4-MOG.2965.-2x3502(naim.3) this one cites the cable resistance as 75 ohms? Is that good enough?

Thanks in advance.

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Welcome EJG, and sorry to hear about the loss of your Dad.

Yes, for a subwoofer feed you could take a pre-level feed from one of the DIN4 signal in/outs on the Hicap. The Hicap wasn’t designed to run long interconnects so when Naim offered their own pre-level sub lead it was “slugged” with a 100R resistor in the DIN plug. It came in either a 5m or 10m length. You could look for one of these, or else have a lead custom made somewhere.

However, a better solution is usually to take a high level reference signal from the speakers themselves (provided the subwoofer has a high level input - e.g. REL et al.). Do your Kans have binding posts?

Of course, Kans themselves have a certain something about the way they perform that may very well be lost by adding a subwoofer. Kans are all about speed, timing and rhythm and it’s easy to lose that with a subwoofer that’s not optimal. So, adding a sub here may not be the best move.


Hi Richard, many thanks for your response.

Just for clarity does a “slugged” resister mean it’s inline?

Understand reference the Kanns! I’m finding they’re absolutely perfect for some genres, but anything that needs a bit more omph, I only get the bass when I crank the volume - which isn’t always possible.

The Kanns do have binding posts; I’d ideally like to be able to plug / unplug the sub easily. Would this just be another set of speaker cables?

Yes, you just use a pair of speaker cables - nothing fancy needed here - and connect off the back of the speaker terminals. That way the amp doesn’t “see” the sub cabling and won’t be upset by it (see FAQ here on speaker cabling and Naim amps for why).

Just turn off the sub when you are listening to music that you feel doesn’t benefit from it. No need to disconnect it.
Having said that, if you can get a sub properly integrated into your system, it can make all music sound better, not just bass heavy music. Get the integration wrong, and it’s the opposite - the music just falls apart. It can take some time and effort to get this right.



Couple of things:

Can I second Richard’s advice to connect via the terminals on the back of the speakers. After trying a couple of other ways I have found that this works best, across a range of speakers.; and

The Kans are great speakers, although, as you observe, they can’t do the low octaves justice. Can I suggest you use a sealed (non-ported) sub. This will match the characteristics of the Kans better. My suggestion would be a BK XXLS-DF 400. This may be too big for your tastes but it is quick and delivers good bass. If you speak to BK they will adjust the crossover range, if needed; they even added a 30min cutoff for me gratis, so that the sub switches into standby.

Thanks all, yes good point r.e. Just turning off the sub if not required.

I’ll look into directly wiring to the terminals. I’ve got some speaker cable hanging around.

Thanks @MrUnderhill will strongly consider that sub. Looks to be a good price.

Thanks all!

Good luck.

If you choose the wiring from the speakers into the neutrik then talk to BK about wiring it. They can advise you.

In my case a friend who is a dealer popped round and did it.

The neutrik wiring is different for a REL I am told.

I use a Naim N-Sub, which works very well and really enhances the sound quality of all music. You can save different preset configurations and switch between them. I have one preset that works really well for nearly all music, and another which is a sort of party mode, with higher gain and filter settings for those times when I want to crank up the volume.
Sadly N-Subs are not so easy to find these days they do appear on the market occasionally.

A small REL sub i think would do the trick, if the room isn’t too large. Something like a REL T/5x

Out of nosiness, may I ask where you have your high level gain, frequency and phasing set, please?

As a starting point you should find the manufacturers quoted frequency range for your speakers, and set the sub just above their lower limit. For example, Naim quote the frequency range for N-Sats as 50Hz to 20kHz. They suggest setting the N-Sub to 60Hz so that there is a little overlap. This is just a strting point - fine tune up or down from there by ear.

For gain, I would suggest that you find the level at which the extra bass from the sub is only just audible. The optimum is probably just a little lower than this, but again, adjust by ear.

Thanks. I’m just setting up a BK sub, by ear, following exactly the instructions you outline, which also is what BK recommend.

I was curious if I’ve ended up near where @MrUnderhill came out as he also has a BK sub and I (may mis-remember) thought SBLs.

I feel like I’m closing in on the right point, based on what I can hear. As it is subjective I was after a data point to compare settings.

Hi @CalamityJack ,

I won’t be much help, BK adjusted the crossover range for me …at the time I was using Living Voice speakers which worked down to 35Hz, BK dropped the lower value of the sub from 40Hz for 30Hz for me. With this in mind my settings are:

The volume it two up from Min, Phase is 0, Freq is two up from Min.

I later changed to Focal 1008be II. The sub impressed by being fast enough to work well with the Focals, and now with the SBLs.

How is it working out for you?


Thanks. That is very helpful, actually. I’ve only had the sub a few days. I found it pretty quick to get it to the point where I think it’s working well with the SBLs. I have the gain low, not dissimilar to your feedback and I’m at 120Hz on the crossover and about to start taking that downwards. After that I’ll try the phasing. Currently sitting at 180 but I’m not hearing much difference at either there or 180. I’m working through CDs and sources to test the impact. However I am very impressed by the overall sound quality and imaging already.

I expect personal taste to play a part in final settings. I think what you describe is where I might be expecting to end up, but I’m keeping an open mind. I’ve promised to add to the sub thread when I get it fully sorted.

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Hi CJ,

Wondered how you are getting on?


Thanks for asking. I’m still playing around but this time with the gain. Ive been back and forth on frequency taking it right down, but I’ve decided across a range of music and sources that I do like the broader frequency range, going up to 120, and it seems good with the phase at 180 so will stick there for now. I found with the phase at zero something didn’t sound quite right, but all these settings have the ability to impact what you hear. I have the gain very low just now - I’m creeping it up slowly this evening but right now it’s probably around the first dot on the scale. The result is very natural, seems to be coming from the SBLs and sounds just like the music I’m familiar with but with with a much stronger base line, better definition to the instruments, more detail, and better resolved sound stage.

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After being unable to do much for a week or so, I’ve been able to do more over the last few days and try different albums on CD, Vinyl and streaming, and not just those with thin bass. With that broader population it’s now obvious that the frequency setting needs to be right down at the level where the SBLs are rolling off. That’s somewhere just above 40Hz in my room. There are albums that benefit from a higher position but when you really listen carefully that causes muffling in the lower frequencies.

On a well-recorded album such as Joni Mitchell’s ‘Both Sides Now’ you can hear when it is just at the perfect point with absolutely crisp, deep bass and an expanded, deep, soundstage. Gain is probably just below the second position from bottom and phase still sounds better to me at 180. I can’t get my head around the omni-directional nature of the lower frequencies, and having the sound seemingly coming from the area of the SBLs and not off to one side.

I’ll continue to tinker a little up and down but it is extraordinary that the sound seems seamless and complements the SBLs so well.

Yep, that’s why they’re called subwoofers! Sounds like you have a good result.

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The First thing to do is set the Phase. For some reason folks don’t quite get phase. Just like your speakers we want the subwoofer in phase with the main speakers. The reason we hook up speakers the way we do is so the main speakers are In Phase with each other. Woofers moving in and out together. We want Subwoofer doing the same thing, moving in and out with the mains. Simplest way to set phase on a sub is to turn the level up say 50% crossover 80hz play some music with repetitive bass lines, switch the phase switch from 0 to 180. One position will have noticeably louder or full bass . That’s the correct position. Leave it there. Then start with crossover and level.

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