NACA4 versus NACA5 speaker cable

[suttonc]

Can anyone tell me the difference between NACA4 and NACA5 speaker cable?

[feeling_zen]

Naim A4/Linn K20 (same cable) uses thinner strands than A5 and a soft flexible sheath. It’s much easier to work with than A5 but sonically less.

OTOH if I had A4 already, I’d not bother upgrading to A5 as the return won’t justify the outlay. Given how old A4 is, if you are still using it, cutting 15cm of each end and reterminating might be a easy and free upgrade.

[timbre]

While this is something that’s been discussed many times both here and on other forums, it appears you need to do some heavy digging to find facts that clearly show the difference between the two NAC cables. So I am not surprised you asked. This is what my web research discovered, nothing is confirmed so take it as you like.

Before the NAC A4, Naim recommended Radio Spares (RS) 56 strand 4.0mm2 single core cable. This cable needed to be lightly twisted together with approx. 5 twists per metre. There are stories of Naim dealers doing the cable twisting during their brakes or slower periods in the back of their stores.

In 1981 Naim launched NAC A4 loudspeaker cable developed by Naim and BICC, A4 was also manufactured by BICC.

I think the NAC A4 spec was as follows;

• 2-core loudspeaker cable available in white or black
• Each core contains 54 strands of 0.3 mm copper (4 sq mm)
• Capacitance: 16pF per metre
• Inductance: 0.93µH per metre

It was sold until 1989. That means the last length of A4 sold in 1989 celebrated its 30th birthday this year!

So why did Naim stop the sales of NAC A4 in 1989?

The story is that sometime in 1980’s BICC infringed Naim’s copyright on the NAC A4 cable. NAC A4 cable was designed by Naim, but BICC started selling a similar cable to Linn under name K20. Linn cable was grey in colour and its still made/sold today.

If you want more info on this search ‘Malcolm Stewart interviews Julian Vereker’ on google.

In 1989 Naim introduced their new cable called NAC A5, not sure who makes the NAC A5.

NAC A5

NAC A5 specifications are as follows:

• 2-core loudspeaker cable available in white or black
• Each core contains 19 strands of 0.5 mm copper (4 sq mm)
• Capacitance: 16pF per metre
• Inductance: 1uH per metre

Please see here for more on Naim speaker cable requirements;

Speaker Cable for Naim power amplifiers

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. We find the supplied Naim speaker plugs to be an optimal match for the 4mm sockets we use on our amplifiers. In addition, …

Also its worth searching ‘NACA5 Revisted review by HIFICRITIC’ on google.

While the reason to develop the NAC A5 was due to failed relationship with BICC, based on the interview with JV Naim did take this opportunity to develop a better cable.

Apart from obvious spec differences above, most manufacturers would not spend time and dollars on R&D unless they are able to introduce something better (granted this is not always the reality) but it makes sense, and Naim history and product development supports this. I guess if I was JV I would have also wanted to stick it to BICC & Linn with my new cable.

So this means that one can assume that NAC A5 would outperform NAC A4. I have read many comments from number of users that A5 is better cable than A4, but its much stiffer. Some even say that the stiff insulation has something to do with sound. I think the insulation is bonded to copper, that means its less likely to be affected by environmental conditions but makes the A5 much stiffer to handle.

To be honest A4 is 30-40 years old now, while cooper is all good, that insulation must be getting tired. If I was buying, it would be an easy decision for me.

I hope this answers your questions but @Richard.Dane or other member might be able to offer more insights than me.

All the best

[Richard.Dane]

Looks like you’ve covered it pretty comprehensively Timbre!

[Mike_S]

IIRC the SN is not as sensitive to the 3.5m minimum length. At least I hope so, as mine is shorter…

[FangfossFlyer]

Very informative, thank you.

[JosquinDesPrez]

I still have some NAC A4 tucked away, so that when someone decides it’s a revelation and betters SL cable I can make a killing on it.

[timbre]

Good plan @JosquinDesPrez…some poor unassuming vintage audio guy will lap it up I am sure. Get a nice wooden box made for it, that will make it sell for top dollar.