Can a REL subwoofer be isolated from the rest of the system when using the REL Speakon cable?

[McNulty]

I'm considering buying one or two REL subwoofers for use in my 2-channel system. I have a class AB amp.

 

REL advices to place the subs in the corners on the room for best SQ. Assuming this is correct, in my system this means at least one of the subs can't be connected to the same power strip as the other hifi components. As most of you will be aware, RELs preferred connection of its subs to a Class A/B amplifier is not with RCA or XLR cables, but with a cable that has a Speakon connection on the subwoofer end and three bare speaker wires (or spades) on the amplifier end, see:  https://www.youtube.com/watch?v=YIenhBQEtE4

 

When connecting subwoofers to the amp through RCA interconnects, products like the Jensen IsoMax or Blue Jeans Cable subwoofer isolation transformer can isolate the subwoofers from the rest of the system, if I understand correctly. My question is if a similar solution exists for the REL speakon cables. Thanks in advance for your answers.   

 

 

 

[sockpit]

Do you have hum?  I’ve had a REL for years and used both line level and the preferred speakon cable.  Both work flawlessly.  

[McNulty]

@sockpit: I haven't purchased the subs yet, so no hum (yet). 

 

Mainly interested in isolating the sub that can't be connected to the power strip based on the findings in this topic: 

 

[sockpit]

I see.  I have a small Topaz IT myself.  But I've never been that concerned to put my subwoofer on it.  It's in the other corner of the room and connected to a completely different outlet/line from the sensitive equipment in my system. (And it's probably a power hog, relatively speaking.)  No hum, in any case.

 

Theoretically, I suppose it could be degrading something, but I rather doubt it.  I've tried plugging only my DAC and LPS 1.2 into the Topaz, and then adding my amp.  Can't hear any difference.  Might just be my middle age ears or my system isn't transparent enough.

 

I like the Topaz for providing some surge protection and a theoretically cleaner line, but at least in my system the differences, if any, are too subtle to matter.  Personally, I wouldn't worry about adding a box between a new REL and your amp on the merely theoretical chance of a problem.

[Lowlands]

I run 2 RELs in stereo. I have VERY minor hum, (not audible during use) not unlikely due to cable lenght and mix of stereo & HT cabling at the same time. I have not checked your suggested options of 'isolating' them ....

I would suggest to take care of common ground, circumvent ground loops, preferably use a single phase & group (especially for amp & subs). But then, that's all obvious and your 2nd outlet may not fit that bill + you seek a fix for that.... (in that case.. sorry). 

Also make sure you check hooking up REL to a balanced vs single-ended amplifier (REL does not want to 'see' two hot lines from the speaker terminal - it assumes an unbalanced signal, you have to apply a mod on a balanced amp !) 

[wgscott]

I don't think there is a way to isolate, in the sense of preventing ground-loops.  However, I think the speak-on cable circuitry has something to prevent this kind of problem (and to cope with balanced class D amps).

 

I'm on my third one now.  It is currently working ok.  I also have it hooked up via LFE to my 5.1 receiver.  Despite this being a recipie for a ground-loop disaster, it is perfectly silent.  (I did have to introduce an isolator on my cable TV input.)

 

The first one had to be warranty-replaced after repeatedly failing.  Customer service was not their strong point.  The replacement, subsequent to warranty expiration, actually caught fire in my living room.  (I had purchased the current one before this happened, or else I would not have).

 

When they are working, they sound great.  But it is by far the most trouble I have ever had with an audio component.  I would suggest at least considering alternatives.