There are a lot of variables, amp power & how much of that is used (volume) so room size can be a factor, then speaker impedance as rated & the lowest actual etc.
In my world there are no hard & fast rules but do acknowledge the various cable guides such as Audioholics are useful.
I would normally go for 2.5mm or greater but would start to be a bit cautious with lengths greater than 10m with 2.5mm.
My speaker cable is 5m of Chord Odyssey which is 3.3mm/2
I see some speaker cable brands have thinner sizes around the 1.5mm mark, I suspect perfectly OK for a smaller & lower volume system.
Chord are one such brand, their Leyline is 16AWG (why a UK company uses American Wire Gauge is beyond me, but hey ho) … 16AWG is 1.31mm/2
But I see on the Chord web page on cables they say “… Leyline can be used in length of over 15 metres before sound quality is directly effected by the length of the cable.”
I can’t understand how gauge impacts on sound. However, my speakers are 8 ohm Spendor 3/5.
Looks like I should cut off a meter or two to check what is going on.
The impedance of the average 2.5mm2 to 4mm2 speaker cables of around 3 to 10m in length makes up a very small percentage of the overall amp/speaker ‘system’ impedance.
The resistance and the capacitance are about the same. The only unknown parameter is the inductance. Usualy when the capacitance is high, the inductance is low, when the capacitance is low, the inductance is high. This makes me think that VdH the Clearwater is very close to NACA5.
To be fair to Naim cable length affect sound quality with most amps/cables I’ve been in contact with. It is just the tech requirement that is unique - but at least Naim can explain why.
All cables suck. All cables effect the sound. Power amps control the movement of drivers in a speaker, that’s creates sound. The more wire the more the power amp has to work through to move the drivers and the more colored the sound will be. That’s the reason numerous companies like ATC like powered speakers. The problem is Marketing; audiophiles like to pick their own speakers cables amp etc. believing they know better.
One-box active speakers do have many advantages, you’re right. However, at the risk of shocking you, there are more possibilities than mere arrogance as to why they are not more popular:
a) A good pair of big active speakers are rarely cheap; buying amp and speakers separately spreads the financial outlay
b) building on the above, upgrading a set of one-box active speakers is not cheap either
c) with more combinations of separate amp/speakers, there are more possibilities for tweaking the sound to suit the source/room/listeners
There was a nice piece in HiFi Critic a while ago, where PMC explained why their early ‘BBC’ play back monitors were active. It was because they could not afford the electrical power losses which would occur in the passive cross overs of a conventional speaker design when trying to reproduce live levels of play back on set! Active enabled them to close couple the amplifiers to each of the drivers incurring lower loses. I expect once appreciated, the benefits of going active stuck with their professional product philosophy.
I guess if you are going for really big sound every dB/W matters, a bit like wringing the max speed out of a car, the last few mph are hard fought for!
Is it really though? In the amplifier all parts are carefully specced, they even hand match resistors. But cables they are being quite vague about. Oh, min 3.5, ideally 7-10; Avoid high capacitance (what’s high?).
As others have often said on this forum, if it’s so critical it would be good if they could provide the specific ranges required.