Noticed there is still some confusion on how to attach a Rel subwoofer to Naim amps. I just went through this with my dealer and here’s what he did…
Amp is olive 250. Speakers are Quad electrostatic 2805s. Subwoofer is Rel s510.
Use Rel Bassline Blue cable specific to Naim. It is 6m long. Stiff similar to A5. Plug the Rel stackable plugs into the 250. Red to right positive. Yellow to left positive. Black to either of the negatives. Makes no difference. Then they supply a 4rth unconnected plug so that goes into the last one. Then plug your A5 speaker cable into the Rel plugs. Simple as that. The other end of the Bassline cable goes to the Rel high level input.
Settings on Rel - crossover all the way down to 20 hz. High/low level input go to 3 detents up and slowly work your way down until it jives perfectly with the speakers. So a bit less than 3 detents.
These settings may seem odd but my dealer is an expert on Quads and this is the way to go. Just do it. Obviously other speakers will have different settings.
The results are just fantastic. This Rel absolutely works with the Quads - fast and open sound full range now. Incredible.
Hope this helps.