How is the Focal Sopra SW 1000 BE Subwoofer connected properly to 252 preamp .?

With a Din 4 to 2 RCA off the Supercap, slugged with a 100r resistor.

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I’d be interested in some views here regarding a 2.1 speaker system. I have an n-SUB on it’s way to me and hope to connect it up using a pair of 6 x metre QED Reference Sub 40 interconnect cables. My main speakers are n-SATs.

How do other members have their sub connected up to their main speakers? What are the advantages/disadvantages of using a high level/low level signal?

I’ve two Rel T9x connected to the power amplifier (high level) and they lift the sound tremendously. I can’t comment on the differences between high and low level connectivity, but I’ve done what Rel recommend.

I never viewed a 2.1 configuration as a serious hifi option, until I tried them out. Fabulous and, I think, gives you some flexibility to optimise your sound to the room.


I have a B&W 610 XP connected (low level) via miniDSP 2x4 that applies adjustment to the bass to correct the residual resonance modes of the room without affecting the sound from the main speakers.
As this small box can be mounted close to the preamp, special cables with resistors are not required, any cable designed to connect DIN output of a Naim preamp to a (non Naim) power amp with phono inputs is suitable. The miniDSP is connected to the sub using normal RCA phono cables.

Before I got the DSP for the sub, I previously tried the high level connection to a sub and in my setup it was noticeably inferior; when I added the DSP in the chain the difference in favour of the low level connection was even greater.

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Ok that’s great, either way. Thanks both :+1:

I can’t wait to get rigged up now (low level), see how things pan out. This is all new to me and I’ve heard very good reports with such setups. Should be up and running by mid-week.

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Biggest thing with subs is getting the crossover right - I found it effectively impossible to get it completely right when trying to do it ‘by ear’, instead I got a miniDSP UMIK-1 and a copy of REW - it was then really easy to get it fundamentally right and just do little tweaks by ear.

For some people it’s essential to get a smooth phase transition to the sub, whereas for other people the phase relationship seems to be almost entirely irrelevant to them. Putting a sub by the main speakers causes a massive phase shift (/ time delay) through the crossover, and the easiest way to deal with this is to move the sub closer to the listener (typically about 1.2m for small subs to about 1.8m closer for the very largest subs).

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Hi Xanthe,
yes for me a smooth phase shift will be quite important. I plan to have my sub around (1.2/1.5 metre) to one side from my main speakers as a starting point. My room is oddly shaped. My ceiling, floor and both walls the speakers are against are of solid masonry construction. My system is firing across a 5.2m x 3.2m room, so quite small. I want the sub to be rather subtle. I shall download the REW software and look at the miniDSP UMIK-1 Omni-Directional USB Measurement Calibrated Microphone. Thank you for your help!

I have found no problems with time delay and suspect the theoretical might only be experienced if you are managing the sound of a stadium concert! I’m not. My room is 4 x 5m. Everything sounds tight.

I am interested to try minidsp, though, to provide some experimentation with equalisation across the frequency range.

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If you can position it and set up the crossover / volume so it disappears then can be very very good.
I couldnt and it bothered be that the elements of the bass were obviously coming from one side.
Was forever up and down fiddling. For some recordings I’d nail it and then it wouldnt work for the next.
I moved onto larger speakers so did away with it.
There are many who have been far more successful. Or use 2.

The high quality of presenting the lower frequencies that subs bring does highlight some poorly produced tracks, where bass is too prominent and, I suspect, is produced for mainstream (pop) playback.

A general problem of transparent systems is that they highlight some crap music producers.

Mastering is an art. Achieving a compromise that suits broadcast, streaming, as well as analogue and digital media and all the myriad delivery mediums is a task that was well beyond me.
It is not unreasonable to suggest hifi playback on high quality systems is down the priorities list.
And of course the ‘loudness war’ of ever increasing compression doesnt help. Particularly when employed to rescue an initially poor recording
Listening to some early Levinson live recordings with virtually zero compression is a revelation.


For me the phase relationship was absolutely critical to getting an integrated sound

For some like myself it’s absolutely critical, and yet some other people are completely untroubled by an abrupt phase shift, it’s very much down to the individual


That’s exactly the problem I had when I didn’t have the phase compensation right - the sound from the sub was completely disconnected from the rest of the music and hence I could always hear where the sub was placed

My point has nothing to with, as you describe it, phase shift. There is an increased sound level. It’s about poor mastering of the product.

Ok i have n-SUB rigged up - i’m not impressed at all - way too bassy.

My partner can’t hear any difference, and says there was nothing missing to begin with. Is there a way of changing the frequency?:flushed:

Have you got the manual? You can change the gain and crossover point easily with the remote or front panel buttons.

Yes i have the manual Chris but i don’t understand it. Playing around with it and i can’t seem to be able to adjust the frequency, only the gain. If can i hear it only slightly it annoys me so no point in having it on? I have the gain set at 65. Does it need to warm up?

From memory, I’m pretty sure you set the filter to 60Hz for use with N-Sats. Then adjust the gain up and down by ear until it sounds right.
If it hasn’t been used for a while I think it will need a fair while to warm up.

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Ah ok, i seem to be getting somewhere now i think. The frequency is now set at 60. Just playing around with level now. I suppose the position will be next once i find my way around. Thanks for your help.