Dual mono with REL Subwoofer

[Antoine]

Hi @PeppaPig

I understand but I’m not sure if that’s possible and have no experience here with my single 250 Pro. When I look at the advanced configurator for a dual Devialet there does seem to be the option to select left or right (and mono) for each Devialet mono block for the ‘mix’ option after you’ve configured a pre-out but I’m not sure if that does what you want. The help function doesn’t seem to work on my iPad otherwise I could have read what it is supposed to do. Perhaps someone else knows or otherwise maybe Devialet support can help.

Edit; I also wrote in my previous post that one could configure a stereo pre-out but after looking at the configurator for a dual mono unit but this does not seem to be correct since one of the outputs on each block is used for the link between the blocks.

Hi Antoine,

I am using high level input for my REL. So automatically the left sub is picking up signal from the left side channel, and the right sub does the same. In any section in the music if there is no signal on left or right channel the sub will pick up nothing from that side.

If AM is only picking up from one side and feed to both side’s subs, I feel like it’s a big step backward.

May be there are a way to workaround it, I haven’t done enough research on the AM yet. But looking at their website, if they put notes saying dual mono is only feed by left side signal I guess most likely it is how it works?

I am very happy with the pair of REL S5 SHO, only less than 3 weeks I have ordered a pair of REL 212/SE, and cannot wait to see them!!

Hi Peppapig, I understand but have a look at the quote I posted earlier. The AM can use both left and right channels and, or so it seems, so can the Devialet output both, one from each monoblock.

Anyway, we’d need someone who has tried to confirm.

Also I forgot to mention it earlier, the exact frequency is point of debate among experts but roughly sound below 80Hz or so is unidirectional so it doesn’t matter much if you apply crossover filtering at or below that frequency.

Enjoy!

[audio_engr]

It’s been a few weeks since I posted on this thread and said that I would report back after the REL open day I attended. 

The open day was at Nintronics in Welwyn Garden City with Rob from REL present to do the demonstrations. They had two REL No.25 subwoofers paired with Focal Maestro Utopia Evo III speakers for the Hifi demo and not surprisingly it sounded great. Even with these £45K speakers the subs added detail to the music across the whole frequency range plus the expected low end extension. The effect was subtle but instantly noticeable with sub on / off listening.

With special trade in deals to be had on the day it was easy to get carried away. I went there with the intention of possibly buying one sub but after hearing them in action I wanted the stereo pair. The No.25 is massive and I’d struggle to fit one beside my speakers let alone two, not to mention the fact that they cost £6.5K each so after a lot of procrastination I opted for two of the reference line G1 Mk2 which I reckoned I could just about fit in. So I traded in an old pair of Castle speakers and the deal was done. Over the next few days I started to have purchase regret and asked myself what the hell I was doing? But I decided to hold on and see if these would make much difference to my my system. 

About a week later Danny from Nintronics and Rob from REL turned up at my house to do the install. Rob recommended using the pre-outs on the back of the Devialets so I did the configuration for this but at first we couldn’t get it working. After a bit of head scratching it turned out that if you program the Tone button on the Devialet remote control for Sub On/Off it doesn’t work properly and we were getting odd results like one sub would work and the other would not. After changing this setting to Pre On/Off instead the second sub burst into life. I found this a bit odd and was also surprised at how little ‘help’ information in the configurator and on the Devialet website there seems to be for setting up subs, particularly if you are configuring a dual setup. Once we had solved this technical issue I left it up to the REL expert to position the subs for me and set the phase, crossovers, and levels. I was surprised how little adjustment was needed in the positioning to make a huge difference to the sound in the listening position. A couple of centimetres at a time made all the difference. As my system is now dual purpose Hifi and Home Theatre we tested the configuration in both modes and it seems that Rob got it just right. The installation was supposed to take about an hour but in reality it took more like 4 until Rob was happy with the setup and I was too. 

That evening I decided to give them the proper Hifi test to see if it had all been worth the expense and hassle and what I experienced was very surprising. The whole musical experience was transformed throughout the entire frequency range, the soundstage was increased massively around the whole room with much better imaging. Instruments and voices were all much more lifelike, warmer, and there was detail on the recordings that I had never heard before! It is hard to put into words how much better these subs make the entire experience and can only say of all the Hifi gear I’ve bought over the last 20 years nothing has had such a profound effect on my system as adding these 2 subwoofers. Needless to say the purchase regret has vanished. I have no idea how these can affect mid and high end sounds but they do and my system now sounds amazing and puts a big grin on my face every time I listen to it!

Today, I was at the REL dealer for over 5 hours. At first, I heard the No.25 followed by the S-series 212/SE and finally the G1 MK II. The No. 25 is outstanding but waaayy too big for my very difficult 'square 18-Ft x 18-Ft dedicated room'. And, I wasn't impressed with the 212/SE but the G1 MKII completely floored me. It was devastatingly good and was mated to Wilson Sasha DAWs that I auditioned. 


I heard classical, organ, opera, smooth jazz, 60's, 70's & 80's rock and was awestruck at what a pair of G1 MKIIs were doing to the overall sonic experience. They sell in the US for $ 5,500 each, meaning $ 11,000 + taxes for a pair. It is indeed a lot of money but I also realise that this would be the single 'massive upgrade' I can do to my existing system and can also sell off the 2nd 440-Pro set and revert to bi-wiring from bi-amping. Hmm! I will have to start saving up of this now ... a pair of G1 MKII when setup right using the High Level input of the Devialet is soooo addictive !!   

[Pim]

 ... a pair of G1 MKII when setup right using the High Level input of the Devialet is soooo addictive !!   

Where the G's you auditioned connected to high level from a Devialet?

[audio_engr]

https://ibb.co/6JFHLds

[Laura]

Today, I was at the REL dealer for over 5 hours. At first, I heard the No.25 followed by the S-series 212/SE and finally the G1 MK II. The No. 25 is outstanding but waaayy too big for my very difficult 'square 18-Ft x 18-Ft dedicated room'. And, I wasn't impressed with the 212/SE but the G1 MKII completely floored me. It was devastatingly good and was mated to Wilson Sasha DAWs that I auditioned. 


I heard classical, organ, opera, smooth jazz, 60's, 70's & 80's rock and was awestruck at what a pair of G1 MKIIs were doing to the overall sonic experience. They sell in the US for $ 5,500 each, meaning $ 11,000 + taxes for a pair. It is indeed a lot of money but I also realise that this would be the single 'massive upgrade' I can do to my existing system and can also sell off the 2nd 440-Pro set and revert to bi-wiring from bi-amping. Hmm! I will have to start saving up of this now ... a pair of G1 MKII when setup right using the High Level input of the Devialet is soooo addictive !!   

Lol oh dear I feel somewhat responsible    I'm glad you experienced the revelation that adding the G1 Mk2s brings! Your problem with the 212/SE was that you listened to them second after the No25 (which I agree are amazing but way too big for a stereo pair setup for most people) so they were always going to sound mediocre. I've heard the G1 Mk2 described as a mini No25 and I think that sounds about right. I'm still in awe of the extra dimension these bring to my system although we are still trying to get to the bottom of the electrical hum that one of mine has. Mr REL is coming back to swap the amp board in one of them as it seems to be that one sub that is causing the issue but so far 10/10 for system improvement and 10/10 for REL customer service! 

I notice on this thread that everyone except me seems to be using or wanting to use the high level input, I asked Mr REL about this last time he was round at my house and was of the opinion that it makes no difference at the sub end and that the Devialets are so good it doesn't matter which you use. For me I'm using SAM on my speakers so high level is not a good idea plus it gives me control to turn the subs on and off if I need to. So the question is has anyone actually tried high vs low level connection and noticed a difference?

[audio_engr]

For what it worth, I have a G1 MK II connected to my Devialet Expert Pro 250 to complement my SF Amati Futura. The range of the Futura is down to 25Hz, the REL is connected via HL cables and is set to start the range at 26Hz down to 15Hz. The result is amazing.  Bass are define, sharp and fast, no comparison with any other Sub I heard. To the point that is a bit of a show stealer. I had people coming to check my system and forgetting Devialet, SF, and all the rest and pretty much only commenting on the incredible quality and precision of the bass, such is a stark difference of what you usually hear.
Definitely check it out.

M

Could you please let me know if the BLACK wire of the HL is left taped off or attached to the Ground post just below the Phono RCAs ?

I am considering G1 MK II Pair and plan to use HL.

[marcor]

For what it worth, I have a G1 MK II connected to my Devialet Expert Pro 250 to complement my SF Amati Futura. The range of the Futura is down to 25Hz, the REL is connected via HL cables and is set to start the range at 26Hz down to 15Hz. The result is amazing.  Bass are define, sharp and fast, no comparison with any other Sub I heard. To the point that is a bit of a show stealer. I had people coming to check my system and forgetting Devialet, SF, and all the rest and pretty much only commenting on the incredible quality and precision of the bass, such is a stark difference of what you usually hear.
Definitely check it out.

M

Could you please let me know if the BLACK wire of the HL is left taped off or attached to the Ground post just below the Phono RCAs ?

I am considering G1 MK II Pair and plan to use HL.

Hello, 
The black wire is connected to the black output of the left speaker.
The red one to the red of the left speaker
The yellow one to the red of the right speaker.
This is the set up that the guy who installed did and I never had humming issues.
Hope it helps
Marco

[audio_engr]

For what it worth, I have a G1 MK II connected to my Devialet Expert Pro 250 to complement my SF Amati Futura. The range of the Futura is down to 25Hz, the REL is connected via HL cables and is set to start the range at 26Hz down to 15Hz. The result is amazing.  Bass are define, sharp and fast, no comparison with any other Sub I heard. To the point that is a bit of a show stealer. I had people coming to check my system and forgetting Devialet, SF, and all the rest and pretty much only commenting on the incredible quality and precision of the bass, such is a stark difference of what you usually hear.
Definitely check it out.

M

Could you please let me know if the BLACK wire of the HL is left taped off or attached to the Ground post just below the Phono RCAs ?

I am considering G1 MK II Pair and plan to use HL.

Hello, 
The black wire is connected to the black output of the left speaker.
The red one to the red of the left speaker
The yellow one to the red of the right speaker.
This is the set up that the guy who installed did and I never had humming issues.
Hope it helps
Marco

This is a very interesting answer. 

According to REL, they have a wiring scheme for Class A/AB amps and a different scheme for Class D amps where the Black wire is not grounded. 

As per your response, with the Black wire connected on Left speaker -ve (black) terminal, this is a typical Class A/AB scheme of wiring. 

Is REL treating the Devialet as a Class A/AB amp and NOT Class D ??

[JohnnySix]

I have read that Devialets behave like classic amps with regard to Ground vs -15v issue. I once had a Rotel Class D that frightened the life out of me when I connected a Rel High Level!

On the subject of Hum, I’ve found that the 2nd hand T7i I got from Nintronics has a mild hum, but my original T7i has none.

PHASE: Having spent weeks measuring the effect of Devialet delay values on sub integration using wavelet spectrograms, I’d beware the suggestion to turn on high pass filter for the mains. It can introduce a significant phase shift that could upset a professional's installation. 
But provided you can measure and compensate for it, it CAN reduce over-thick bass in the crossover region.

[audio_engr]

I have read that Devialets behave like classic amps with regard to Ground vs -15v issue. I once had a Rotel Class D that frightened the life out of me when I connected a Rel High Level!

On the subject of Hum, I’ve found that the 2nd hand T7i I got from Nintronics has a mild hum, but my original T7i has none.

PHASE: Having spent weeks measuring the effect of Devialet delay values on sub integration using wavelet spectrograms, I’d beware the suggestion to turn on high pass filter for the mains. It can introduce a significant phase shift that could upset a professional's installation. 
But provided you can measure and compensate for it, it CAN reduce over-thick bass in the crossover region.

Thanks for your response & recommendations. 

Anyway, so long possible, I'd go with High-Level setup of the RELs. REL G1 MK II designer John Hunter tells me its much more dynamic and much superior integration with the Main speakers than using Low-level. I am only concerned that it seems the Black (ground) wire also needs to be connected in this case with Devialets. Just hope it doesn't mess up the Amps or my main speakers ...