Issue with REL G2 Subwoofer

I’d suggest you speak to REL directly, as there seems to be a difference between the two subwoofers. The new one may even be faulty. 

I agree.  I would speak to your supplying dealer.  If the the Storm and B1 were fine but you're getting issues with the G2 (including possible consequential damage, by the sound of it), then it may well be that the latter is faulty.  Definitely something I'd want to discuss with the dealer.

Thanks for the reply guys, I tested the REL G2 using the high level input at the dealership with the high level neutrik cable and it was working fine although it was connected to a non Naim system.

I think your dealer is going to be the best person to help you get to the bottom of the problem here, unless REL can explain some difference between the two models that might explain the issue.

Can you connect it using the low level input?  There are substantial advantages to this type of connection anyway.

It's theoretically possible for this type of behaviour to be caused by interaction of the back emf from the resonant behaviour of the LF driver cones of the main speakers affecting the input to the sub when using a high level connection; this can cause acoustic feedback.  When using a high level connection, this effect will always cause some degree of distortion of the signal to the sub.

Will try speaking to my dealer, as for connecting it to the low level input, I thought to get the best out of the REL sub you need to connect it to the high level input?

I am aware that REL recommend the high level input, but among all the manufacturers of subs, I believe they are alone in this opinion (most say there's little or no difference or that the advantages and disadvantages are balanced and small).  I have yet to hear an explanation as to why REL believe the high level inputs have a definitive advantage (unless they know of an issue with the design of their low level inputs).

A further small complication when using the high level inputs occurs when trying to time align the sub to the main speakers; the LF group delay of the power amp is also in the signal chain to the sub, slightly increasing the time differential of the crossover when compared to that using the low level inputs.  This makes acoustic integration of the sub a bit more difficult.

I believe the reason REL advise the high level input, for connection to a music stereo system, is that the crossover has a more gradual slope than the low level input crossover (which is intended for LF special effects, rather than music). They say this gradual crossover makes integration with full range speakers easier.

I have always used the REL on the high level,  from the speaker terminals on my Naim power amps. (currently a NAP300). Never had any problems, and tend to get irritated by Naim’s stated quirky amplifier requirements e.g. huge lengths of bulky speaker cable in a small room. As far as I’m aware, Naim have advised against subs in music stereo systems anyway, but I happen to love Harbeth HP3s, and they definitely sound better with a bit of sub.

For what it’s worth, I found my Naim sub to sound a little better using the high level connection from the speaker sockets, as per Naim’s recommendation, but the difference was small. A decent low level interconnect might cost more, but maybe worth a try if you can’t get the high level connection working. I think I would want to know why this problem arose in the first place, though. 

I’ve never used a Supercap, does this have a second output suitable for a sub?

I have two REL R-328 and connect the high-level inputs to my speaker terminals. I have no issues and love the improvement over using the speakers alone. REL does make a cable specifically for Naim amps (it has some kind of inline circuitry in the cable) so one can connect to the amp terminals rather than the speaker terminals, but I already have decent cables and the REL ones are $500-600 (and I would need two).

@Rockingdoc, yes, when trying to integrate by ear, a more gentle slope to the filter does make integration a lot easier, but I found the end result from this approach with my system was still far from optimal.

However, from my later experiments with setup using a calibrated instrumentation microphone, followed with confirmation by ear, a far better result could be achieved by using a more precise setup and a much faster filter slope.

Thanks for the feedback guys, much appreciated, first thing I'll do is speak to my dealer just to double check that the high level connection is not faulty. If it's not I'll try using the low level input instead so I have another silly question how do I connect it to the Naim end if I use the low level input??

I did read up on the REL website that they have specifically developed a special Bassline blue cable just for Naim.

Eu Jin posted:

Thanks for the feedback guys, much appreciated, first thing I'll do is speak to my dealer just to double check that the high level connection is not faulty. If it's not I'll try using the low level input instead so I have another silly question how do I connect it to the Naim end if I use the low level input??

I did read up on the REL website that they have specifically developed a special Bassline blue cable just for Naim.

You need the proper output for the REL low level input, and the 252 doesn't have it. That is meant for the .1 LFE output from a digital HT system. You need to get the high level input sorted to use the sub with a two-channel system.

BTW: when I was using a single REL sub, yellow and black went to +/- on left channel, and red went to + on right channel. Have you tried that?

Eu Jin posted:

Hi everyone not sure if anyone can help me with this issue i'm having with connecting my Naim system to a REL G2.

I'm currently a proud owner of the following active Naim System:

 

NAC252

Supercap DR

2 X NAP 200

CDS3

XPS2

NDAC

SNAXO 242

HiCap

Allae

 

I have been using REL subwoofers as a complement to my system above for years and I have always connected the REL's using the Speakon High Level cables to the back of my Allae Speakers ( red to the Right + speaker terminal, black to the Right - speaker terminal and yellow to the left + speaker terminal) and the other end to the high level input of the REL subwoofer.

 

I first had a REL Storm, REL B1 and I have recently got my REL G2 delivered. For some reason when I tried connecting my REL G2  the same way I have connected the REL B1, a loud repeating signal type sound automatically played itself on my speakers (even when the volume knob was set to the lowest) to which immediately turn off my power amps. I then disconnected the REL G2 and reconnected the REL B1 and the issue went away. I then disconnected REL B1 and connected the REL G2 and the same issue occurred again. I have since then connected the REL B1 back again however I have also then realised that my left tweeter on my Allae is now busted.

 

Can you please advise how can I resolve this issue as I do not want my new subwoofer to go to waste. The only thing I can think of is that my previous REL Storm and REL B1 had both a unbalanced and balanced High Level input while my new REL G2 only has one high level input and it does not say if it's balanced or unbalanced if it actually matters. 

 

The Naim forums strongly advise against connecting the REL Speakon High level neutrik cables to the back of the Naim Amps and I definitely do not want to risk damaging anything further.

 

Any help or advise on how to resolve this issue is very much appreciated.

 

Hi Eu Jin.

I use two G2 sub's on a nsystem VERY simular to yours - 252/SC DR/HDX/NDAC/NAP200/SopraNo2 - and had the same initial issue with hum/noise when connecting no 2 sub...I then found that the problem dissapeared if I powered the sub's on a different mains power group than the rest of the system. I have also connected the sub's directly to the speaker terminals - but You have to be careful as You use power from two different amps, which You do NOT want to get connected - t,drop a mail to  but here is a part of the owners manual referring to an active set-up like yours, but if in doubt, drop a mail directly to REL, - they are very good at solving problems like this

RaceTripper posted:

You need the proper output for the REL low level input, and the 252 doesn't have it. That is meant for the .1 LFE output from a digital HT system. You need to get the high level input sorted to use the sub with a two-channel system.

...

Are you saying that the low level input doesn't have controls for the level and cut off frequency?

Eu Jin posted:

...
If it's not I'll try using the low level input instead so I have another silly question how do I connect it to the Naim end if I use the low level input??
...

You connect it to one (or two) of the spare DIN4 output sockets of the SuperCap.

 ....

but You have to be careful as You use power from two different amps, which You do NOT want to get connected - t,drop a mail to  but here is a part of the owners manual referring to an active set-up like yours, but if in doubt, drop a mail directly to REL, - they are very good at solving problems like this

.....

I have dropped an email to REL to see what they say, has anyone used the REL Bassline Blue cable made specifically for Naim??

Also Sternberg what manual are you referring to? the Naim one?

Huge posted:

Eu Jin posted:

...
If it's not I'll try using the low level input instead so I have another silly question how do I connect it to the Naim end if I use the low level input??
...

You connect it to one (or two) of the spare DIN4 output sockets of the SuperCap.

Thanks

Huge posted:

RaceTripper posted:

You need the proper output for the REL low level input, and the 252 doesn't have it. That is meant for the .1 LFE output from a digital HT system. You need to get the high level input sorted to use the sub with a two-channel system.

...

Are you saying that the low level input doesn't have controls for the level and cut off frequency?

Sorry, come to think of it now, I did once have a cable made up so I could connect my HiCap to the low level input. I was never able to get it integrated satisfactorily. My dealer confirmed it doesn't work as well as high level input for two channel audio.