Uniti Atom to subwoofer High-Level connection

If taking a high level signal to the subwoofer, then with any Naim amp in play I would strongly advise talking the reference signal from the loudspeaker end (i.e. off the terminals of the speakers rather than the amp). it's a reference signal so any thin cable should do the trick - FWIW we used to use Chord Ley Line for this.

Richards suggestion works well for me. I use Chord Sarsen, as it’s conveniently thin, but any old cable will do. This makes it cheaper than a low level connection which needs a more expensive lead. You should be able to solder both sets of cable onto the same set of bananas, depending on your current arrangement. 

I use a sub connected to my Nova via the low level inputs and it's fine. Why not borrow a sub and see if that method works for you? 

I had a look at the REL and it seems a faff to set up! My Velodyne DD-12 came with a microphone, remote control, and set up software displayed on my tv which meant I could set it up at the listening position. It also has many more adjustments. Check out Velodynes - I got mine for £500 second hand. Other subs are available.

I use a Pair of Focal Chorus 826W UK Ltd Editions (very similar to your Aria 926) with a sub (MJ Acoustics REF200) driven off an 82/Supercap/250.

As Richard suggests I use a high level connection from the speaker terminals back to the sub.

This is the ideal way to do it.

If I was looking for a sub now, I would consider one of the BK models. They used to manufacture Rel subs until Rel moved production to China, and now sell their own range direct, at pretty cheap prices.

Richard Dane posted:

If taking a high level signal to the subwoofer, then with any Naim amp in play I would strongly advise talking the reference signal from the loudspeaker end (i.e. off the terminals of the speakers rather than the amp). it's a reference signal so any thin cable should do the trick - FWIW we used to use Chord Ley Line for this.

Thanks, I'll try this method. Seems it will be easier to connect cables to speaker inputs compared to amp output. But I think subwoofer cable will be longer in this case.

Also doesn't such connection influence sound quality in overall? Because amplifier outputs will have to drive speakers + sub signal (though in small extent).

ChrisSU posted:

Richards suggestion works well for me. I use Chord Sarsen, as it’s conveniently thin, but any old cable will do. This makes it cheaper than a low level connection which needs a more expensive lead. You should be able to solder both sets of cable onto the same set of bananas, depending on your current arrangement. 

Maybe it is cheaper also, but I'm going not for cheaper method, but for better quality method.

Subwoofer manufacturers (including REL) claims that High-level connection is the best possible connection for stereo systems (for music listening). Because subwoofer gets EXACTLY the same signal as speakers get.

Pev posted:

I use a sub connected to my Nova via the low level inputs and it's fine. Why not borrow a sub and see if that method works for you? 

I had a look at the REL and it seems a faff to set up! My Velodyne DD-12 came with a microphone, remote control, and set up software displayed on my tv which meant I could set it up at the listening position. It also has many more adjustments. Check out Velodynes - I got mine for £500 second hand. Other subs are available.

I know Velodynes are good subs also. But I'm not sure if I will be able get one to test in our region. Also, I was thinking about SVS.

As for connection, I think high-level should be better quality compared to low level. All manufacturers and reviews claim that.

Mike1380 posted:

I use a Pair of Focal Chorus 826W UK Ltd Editions (very similar to your Aria 926) with a sub (MJ Acoustics REF200) driven off an 82/Supercap/250.

As Richard suggests I use a high level connection from the speaker terminals back to the sub.

This is the ideal way to do it.

Just for interest, what frequency range you've set for this sub that work well for you?

tony123 posted:

...Also doesn't such connection influence sound quality in overall? Because amplifier outputs will have to drive speakers + sub signal (though in small extent).

With a Naim amp, this is the preferred connection because then the amp just sees the speaker cable and speakers - provided the speaker cable is within Naim specs then stability is maintained.  Adding on some benign cable for the sub reference signal at the speaker end should make little or no difference here, whereas, if you were to connect it at the amp end then that cabling would be "seen" by the amp and may lead to instability.

Hi I use a Velodyne DD10+ with low level connections ......... its superb. The Velodyne - DD+ series are expensive but boy do they kick ......... and the room compensation is fabulous ......... in a very small room I get a measured frequency response to within -3dB down to around 25hz. However I do not use this sub for overblown impact I turn it right down and it rolls and blends in beautifully ........... it rolls in around 60hz and gently takes over from the pmc's. I can honestly say the Velodyne is one of the best hi Fi purchases I have ever made. The controls on the Velodyne turn you into a bit of a bass god! ........... but...only at the hot seat .. it cannot remove bass hot spots around the room. Ultimately .... probably 2 Velodynes would be optimal..................and reduce hot spots. SVS are highly regarded but I don't think their compensation is so sophisticated............. I tried a REL and hated it......it did not suit my system or room.

tony123 posted:

ChrisSU posted:

Richards suggestion works well for me. I use Chord Sarsen, as it’s conveniently thin, but any old cable will do. This makes it cheaper than a low level connection which needs a more expensive lead. You should be able to solder both sets of cable onto the same set of bananas, depending on your current arrangement. 

Maybe it is cheaper also, but I'm going not for cheaper method, but for better quality method.

Subwoofer manufacturers (including REL) claims that High-level connection is the best possible connection for stereo systems (for music listening). Because subwoofer gets EXACTLY the same signal as speakers get.

Having tried both methods, the differences in sound were not that great between high and low level connections in my system. (At the time, I was using a Superuniti and a Naim N-Sub.) I chose the high level option as it sounded very slightly better, but mainly because, with my room layout, routing the cables was much easier. I would still have been happy with the low level connection, although the lead, which the seller of the sub included in the deal, would have cost about £300. 

Can I ask if using the high level method suggested above do you take the +ve from each channel or both from one speaker to feed the sub woofer please.

Proterra posted:

Can I ask if using the high level method suggested above do you take the +ve from each channel or both from one speaker to feed the sub woofer please.

You need to take it from both speakers, or you will only get one of the two stereo channels. Rel subs, and some others, only connect the - to one of the two channels with their 3 core Neutrik connection lead, otherwise use regular 2 core speaker cable from both speakers. 

I guess it depends on the sub. You want signal from both speakers as otherwise you only have signal from on of the channels.  On the n-Sub you have a pair of speaker inputs, on something like a REL I think it's a Speakon connector where you have to combine the channels before input ( I think - it's been many years since I had a REL at home).

I have a Nova connected to my AV system for the right /left front channels and use a  Rel T/7i which came with a long High level lead which connects on the speaker terminals with yellow and black on one speaker and red on the other speaker. I just had to split open the insulation to achieve this. The lead is about 5 m long.

tony123 posted:

Mike1380 posted:

I use a Pair of Focal Chorus 826W UK Ltd Editions (very similar to your Aria 926) with a sub (MJ Acoustics REF200) driven off an 82/Supercap/250.

As Richard suggests I use a high level connection from the speaker terminals back to the sub.

This is the ideal way to do it.

Just for interest, what frequency range you've set for this sub that work well for you?

My REF200 rolls in at 42Hz.  In our old place it was 48Hz, but the concrete floors in our current home really help the floorstanders out at the bottom of their range.

The speakers still drive down to around 38Hz but are rolling off by about -3db in room at that point, so I give a little overlap.

The hardest part of picking a sub was finding one which was fast enough. The Chorus 826W has the Focal W cone which is lightning quick and very light. Ironically even my old Focal SW904 Sub couldn't keep up, and that was also a W cone driver!  Not the biggest problem with it though.... Roll off only adjustable in 5Hz steps (bad) and phase in 45 degree steps (disaster).

The MJ is very quick, has 1Hz and 1 degree adjustments, and was a piece of cake to tune to the room.

Just as well... I run AV uniti gain through my 82/SC/250 with a NAP-V175, Oppo 203, and use another REF200 running high level on the centre channel. And another MJ sub (Pro50mk2) running high level on the rears. And a big monster Dynaudio sub just for LFE!

Yes, I am certifiable. I also hate using bass redirection in my AV processor as (and this is ALL AV processors) as soon as you set any speaker to small, the LFE level is compressed by 10db. Ugh!

I’ve tried hooking up a REL S/5 to my Nova using the line level output (right) and was so so disappointed. I was using a 15 year-old Defintive Technology SuperCube II connected via RCA to the left output and it sounded amazing.

I called REL for help, they really push the high level output, but Naim’s banana plug *only* speaker connects don’t make that possible unless you want to solder it on some how (thanks Naim, will send a muffin basket for that brilliant design decision along with another for no MQA support on a $7500 piece of kit that hisses).

As a last resort I connected both left and right line-level outputs from the Nova to the sub and it came alive.  I don’t know whether Naim is using some high-pass filter on the right RCA channel or which one they intend to be used as subwoofer (because the documentation definitely says it supports a sub), but connecting both channels to the subwoofer made it come alive (don’t know if this is possible on every sub).

Captain jack, you always need both channels, otherwise you only get the bass from one channel.  Some subs sum the bass from L+R to mono internally, others require it to be summed before it reaches the sub - this can easily be done by appropriately wiring the sub lead.  

Naim's 4mm banana plug sockets should not pose an issue for high level connection because Naim strongly advise against connecting from the amp outputs.  Rather, it is much better to connect from the terminals at the back of your speakers.  That way the amp only sees the load presented by your speakers.

Anyway, glad it's working for you now.

Thanks Richard - I can’t explain why the older, smaller, less powerful sub connected only to the left line-level output worked quite well but the right channel did not.   

As for connecting the high level subwoofer cable to the speaker terminals, that’s a giant pain in the a** with Rel which uses a proprietary connector.  You would need to buy a much longer cable from Rel to the tune of $500 ish and then carefully split it to connect it to speakers that are 8 feet apart.

Or, Naim could have just provided a more versatile binding post that accepted spades (and bare wire)

Also, how is the load at the amp terminals any different than at the binding posts of the speakers (apart from what should be a very inconsequential impedance difference from the speaker cable)? It’s the same circuit connected just a few feet apart... the whole point of the high level in is to present the same amplified signal to the sub that the speakers see ...

Naim will always, where possible, go for the solution that provides best performance; in this case the 4mm socket and supplied SA8 plugs that require the cable to be soldered to the pins.

Yes, to use the REL high level input with Naim requires a custom cable to be made up, but plenty of suppliers can do this (including many dealers) for a fraction of the price you quote.  The cable itself need not be anything special.