3m is the minimum recommended length of Super Lumina speaker cable.
As Jan alludes to in his post above, Naim power amps don’t have added inductance networks for stability, instead they rely on the speaker cable to provide the necessary inductance - this was found to give much better performance. It does mean though that you need to stick to Naim’s recommendations re. speaker cabling, giving a combination of low capacitance and moderately high inductance;