Cable length again - running active - is length more critical on LF or HF?

I’ve spent much of the day moving the system back to where it used to be.

It’s been in the communal living area for too long, an effect which snowballed as I temporarily had a Nova and Epos speakers while other stuff was in storage. As I found bits and bobs I hooked it all up and incorporated the Nova as an audio source into an active system.

I seem to have 2 different set lengths of NACA5 - the shorter pair is a bit short at 3m (I know, not ideal, suspect I got a short run for use with the Nova). The other pair is >5m. I know I have another similar length pair somewhere but where is the question.

So while I appreciate cable runs ought to be at least 3.5m, I’m just trying to work out if the shorter cable run would be better on LF or HF duties (one olive NAP 250 for LF, one for HF, fed from SNAXO 242).

Anyone know?

In my opinion it makes absolutely no difference.

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FWIW, Naim recommend that speaker cable lengths should be the same.

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I certainly think it makes sense if you have 2 sets of different length cable runs to use one set on LF and the other on HF, rather than say using the shorter pair to the speaker closest to the amp. If different lengths could subtly alter the sound you’d certainly want to try to match LF or HF characteristics.

Where it then gets interesting I suppose (and yes I know 3m is a bit short), is given the speaker cable FAQ:

Naim power amplifiers do not have extra inductance networks in the output. Naim prefer the more elegant solution of allowing the speaker cable to provide the correct inductance and capacitance.

To do so, a minimum of 3.5 metres per channel of NACA4 or NACA5 cable is required – although the optimum length is around 5-10 metres with a maximum recommended length of 20 metres.

Is a shorter length likely to adversely effect HF or LF more? I don’t possess the electrical insight, maybe @Xanthe might have an idea. Ultimately the 3m pair will be replaced by a longer set when I find them - if they have been putting any strain on the NAPs it’s a bit late as they had been in situ for several years. I honestly do not recall any dealer advice to ensure longer than 3.5m NACA4/5 lengths in the early 1990s - along with many things we have far more information at our disposal and the forum FAQ is a great resource.

I’m really not sure where the 3m pair of NACA5 came from - maybe a short pair I used long ago in the bedroom with an old Linn amp and small speakers, maybe a short pair I had to use with my first Naim purchase of NAC72/NAP250/HICAP at my parents house, maybe I did get them when the I got the Nova.

I’ve never tried it before but the ‘jumping jack’ arrangement for extra cable length worked a treat with the cable under the bottom shelf of a long two tier coffee table I’m using for now for the NAPs and Linn/Naim PSUs.

Actually quite tricky to work out where to place many items attempting to separate brain/brawn with several 2 tier tables due to the standard interconnect lengths. Yes, I’d love to have Fraim or other dedicated hi-fi racks but this can’t be justified currently on cost, and in fairness a combination of John Lewis/Ikea tables is not too bad visually though the 3 tier Sound Organisation rack doesn’t match. I’m trying to keep racks low between the speakers to maximise available area for projection between them, and it actually works pretty well. Next issue will be getting the AV processor incorporated somewhere to handle several AV sources to the projector, then a decision of whether or not to set it up as 4.0 or 5.0 or stick with stereo. The Epos ES 14s used to work very well as rear speakers and gave deep bass extension for movies. Less convinced I want to reincorporate a centre speaker - a) visually and b) would mess up my rack arrangement.

It would be very nice if this were true and I’d certainly love to think so. I really knew nothing about 3.5m minimum lengths until I frequented this forum and it’s explained well in the FAQ.

Sonic differences might be marginal but I’m sure Naim have the facility to easily test different lengths and the FAQ certainly suggests benefits with longer lengths, something most of us can’t readily A/B at home unless we have local dealers with several cable sets or simply purchasing new cable which is always a gamble done blind.

The longer term concern would be putting ‘strain’ on the power amp electronics if the cable is an integral part of the amps output stage - again this was never something my old dealer mentioned decades ago.

This might be a simplistic point, but the shorter pair will have lower resistance and capacitance which, if we consider them acting as a first-order low-pass filter, will increase their cutoff frequency and make them more likely to block lower frequencies.

That said, the values of R and C for a speaker cable are so low that it would send the cutoff frequency way above even a dolphin’s hearing, so this may be utterly moot!


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This may all be a bit theoretical, but it really boils down to:

a) if you have a shorter pair of speaker cables in a Naim active system are they sonically better connecting HF or LF drivers in speakers such as SBLs?
b) more important perhaps, if there are potentially adverse effects on the NAPs using a shorter pair, will and adverse effect be more likely driving LF or HF for a given cable length.

As I say perhaps theoretical, just need to locate the longer set of NACA5 I have somewhere and could have sworn I saw a few weeks ago coiled up in an old zipped plastic ‘pillow’ packaging.

In the short term i would use the short cables on hf and the long cables on bass.
As the cables are technically part of the amp ,the amp driving hf is under less stress (they dont usually get as warm hot as lf bass driving amps in an active set)so get the bass amp closer to optimal operating parameters

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Thanks, that’s what I opted for the other day with similar logic. I’ve seen recommendations before however that if you mix power amps that Naim feel the higher rated one should be on HF duties - whether this is based on listening tests alone or electrical parameters I have no idea but like you I’d assume LF units require more effort to control them.

It’s all sounding quite good at the moment, though maybe a bit thin in the midrange/upper bass - we’ve used a pair of Apple HomePods as stereo speakers (the original larger ones) via Airplay from AppleTv hooked to the projector in recent months and they really do sound pretty good. I swapped back to them last night expecting to be disappointed but there was a lot more midrange/bass warmth - maybe colouration, but interesting all the same. The active system has excellent scale, wider soundstage and detail but I may prefer a bit more warmth (this is via Airplay to the Nova as a ‘source’ hooked to the active system. Might well sound different once I get the AV amp hooked up to route 4k source to the projector as I could then take analogue out from that direct to the NAC 282 for audio.

May be time to check the SNAXO242 as I believe pots are set to zero by default, as best as I can ascertain it may be a case of tweaking for the room, but detail are scanty unlike an ancient NAXO with pencil marks indicating position I assume done at the factory (unless on dealer set up for the original owner).

There is a bit of complexity here:

Assuming we are talking about a true active system with the crossover in the low level signal and multiple power amps (NOT just a remote passive crossover at the amp end - which is more like bi-wiring); then the amp connected to the shorter cables is more likely to be affected by any potential instability issues.

In the case of the LF amp, both the power demand on the amp and voltage swing from the output of the amp are greater, so the power and voltage margins are less. However, the voice coil of the LF driver has significant inductance itself, and this is likely to be greater than the inductance of the voice coil of the HF driver. This means that the inductance seen from the amp is greater than if the shorter cables are used on the HF side. In addition if there is any ultrasonic instability in the amp, the LF driver will be substantially less affected than the HF driver would be.

On the other hand, for the HF amp both the power demand on the amp and voltage swing from the output of the amp are lower, so the power and voltage margins are greater.

I’d measure the inductance of the drivers and go with the shorter cables on driver with the greater inductance (i.e. probably the LF side).

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That’s a very helpful reply, many thanks Xanthe!

I thought it’d be more complex than my simple assumptions allowed for and hadn’t considered the inductance of the drivers themselves.

Presumably I could measure the inductance with a cheap multimeter/calculations (typically I found one the other day in storage but left it there as I didn’t’t see an immediate need for it!).

I think it’s quite an interesting question generally.

Active systems in Naim land are probably less popular than a few decades ago when Naim still made speakers, but I’d surmise when I went active in the late 90’s with SBLs that I already had a good length pair of NACA5 from passive days with Epos speakers. Maybe I’m an exception but I likely would just have bought a single new pair of NACA5 cables to complement the existing ones rather than buying all new speaker cables after going active, heck I might even have used NACA4 and NACA5 for a while!

As ever YMMV. I like my Naim gear but I don’t always agree with their advice. Your truth isn’t necessarily my truth.

Fair enough.

Well, typically looking for something completely different I came across the other set of longer NACA5 leads - I just can’t face installing them in this heat!

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Get rid of the 3 metre cable, it’s too short.

It costs b*gger all to buy, so start again and get a proper length (as the actress said to the bishop).

Both my channels of KS-1 are 3 metres sounds great to me. :roll_eyes: :+1:t2:


It’s not ultra expensive I agree but 2x5m would cost nearly £400 plus termination, you may not have seen the post immediately prior to yours but looking for something else I’ve now found the other set of A5 which is either 5m or 7m in length, I just can’t face installing it during this heatwave, but at least I know where it is and have saved between £400-£560. :scream_cat:

I am an inveterate hoarder and must change this habit which was probably learned from my parents who were very much of the ‘make do and mend’ mentality. Ever since I left University and had my first proper wage I have spent far too much on gadgets which initially may have been ‘best in class’ but rapidly devalued or were superceded. I find it hard to chuck previously expensive items even if they are now redundant - bonkers really.

There are so many leads/gadgets/tools/whatever I know I have but cannot quickly locate - I therefore often buy something again and of course the item then turns up a few days later.

Alley Cat, regarding the last para of your post, there’s a wel-known scientific principle involved.

It’s called The Theory Of Temporary Invisibility.

It explains, and accounts for, one of life’s eternal mysteries.

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I’ve never heard of that concept but the phenomenon most surely exists.

Does it explain missing socks ?