Genelec Dual Sub Optimisation

[Sparky]

Hi all,

I'm hoping to hear from some Genelec subwoofer owners/users with regards to their set up at home/studio.
I own a pair of 8341's and have decided to go "all Genelec" in my home set up and have ordered a pair of 7360A's.
Focusing on the subwoofers only, I currently use a pair of active sealed 12" subs managed by a minidsp SHD where they have been level matched, aligned and crossed over at a suitable frequency with the use of REW.
With the above, I have managed to produce a flat response from 18hz onwards which I am really proud of (because it took me over 2 years to get right) so I am hoping to achieve a similar thing with two 7360A's and a GLM kit.

But here is the issue..........after doing a bit of digging, I have found that Genelec and dual subs do not necessarily mix well and this concerns me greatly.
My hope was to install the two subs, let the GLM kit align them together as one sub then select the closet monitor to choose an appropriate cross-over point.

My Genelec speakers will be fed through an RME ADI2 PRO FS R BE via the AES/EBU output so digital all the way to each driver.

Please somebody tell me that the process is going to go well otherwise I've just blown over £3k on subs that aren't going to blend together as they rightly should.

 

[Sancus]

Genelec aligns subs with individual speakers separately, I'm fairly sure it does nothing at all with them combined. It isn't a great system for multi-sub IMO. I've talked about this at length elsewhere.

That doesn't mean you'll have actually bad results though. Just not optimal.

 

[Sparky]

Genelec aligns subs with individual speakers separately, I'm fairly sure it does nothing at all with them combined. It isn't a great system for multi-sub IMO. I've talked about this at length elsewhere.

That doesn't mean you'll have actually bad results though. Just not optimal.

Hi Sancus,

Thanks for your input, I appreciate it.
Sounds like I'm going to be disappointed then.

I'll head over to the link you've added to see just how disappointed I'm going to actually be! LOL

 

[Kervel]

Technically we don't know how Genelec sets filters--its all done automatically in the cloud nowadays and they may have changed the algorithm already. All measurements have a timing reference and you can take them at various positions, so the data is there to do a multisub optimization.

I guess you have to calibrate, and subsequently check with Umik+Rew. You can compare I) the optimized GLM response running a sweep with both subs and mains, ii) turn off left sub and run sweep with only right sub and mains but using same GLM filters, iii) run sweep with only left sub and mains.

Now, *fingers crossed* that the acoustic sum of running both subs yields a flatter response.

 

[Sparky]

Technically we don't know how Genelec sets filters--its all done automatically in the cloud nowadays and they may have changed the algorithm already. All measurements have a timing reference and you can take them at various positions, so the data is there to do a multisub optimization.

I guess you have to calibrate, and subsequently check with Umik+Rew. You can compare I) the optimized GLM response running a sweep with both subs and mains, ii) turn off left sub and run sweep with only right sub and mains but using same GLM filters, iii) run sweep with only left sub and mains.

Now, *fingers crossed* that the acoustic sum of running both subs yields a flatter response.

Agreed. GLM 4.2 is very powerful indeed and far surpasses anything GLM did before version 4 was released not so long ago.
Each release of GLM brings major improvement so I'm hoping that by now, they'll have got to grips with subwoofer integration.

Need to do some more digging here I think.

 

[Sparky]

One good thing is that, if it turns out that I do need to turn to REW to check integration etc, I will be able to do that quite easily as I e done it many many times over the years.

Just hope it doesn't come to that!

 

[Sancus]

Technically we don't know how Genelec sets filters--its all done automatically in the cloud nowadays and they may have changed the algorithm already. All measurements have a timing reference and you can take them at various positions, so the data is there to do a multisub optimization.

I mean I asked their support at the end of 2020 and they confirmed I was correct, subs are calibrated individually only. They have very good support that is easily able to answer complex questions btw.

It's possible they added multi-sub since then. I doubt it, since it would have been in a patch note and I don't recall anything like that. Also, bass management and multi-sub are not really something that most studios are interested in for various reasons.

 

[Pekka Perämoottori]

I mean I asked their support at the end of 2020 and they confirmed I was correct, subs are calibrated individually only. They have very good support that is easily able to answer complex questions btw.

It's possible they added multi-sub since then. I doubt it, since it would have been in a patch note and I don't recall anything like that. Also, bass management and multi-sub are not really something that most studios are interested in for various reasons.

2020 was three years ago, things have changed. More careful release notes -reading, please...


From GLM 4.2.0 -release note:

"The new Subwoofer group ID enables compensation of multiple subwoofers working together on the same set of audio channels."



So, since version 4.2, GLM can now adjust/optimise multiple subwoofers.

 

[tifune]

2020 was three years ago, things have changed. More careful release notes -reading, please...


From GLM 4.2.0 -release note:

"The new Subwoofer group ID enables compensation of multiple subwoofers working together on the same set of audio channels."



So, since version 4.2, GLM can now adjust/optimise multiple subwoofers.

Don't get your hopes too high on this; I asked support specifically about that and the answer I got was: it's only volume compensation for multiple subs receiving the same signal. For example, a Y-cable from 1 sub out on your AVR.

 

[Kervel]

From GLM 4.2.0 -release note:

"The new Subwoofer group ID enables compensation of multiple subwoofers working together on the same set of audio channels."

But what does the quote mean? In the time of analogue subs, having two daisy changed requieres reducing the level by 6db each... Does it do only this?

Or do they also measure the accoustic sum of the two sub responses to flatten this out? I'd be curious...

 

[Sancus]

Don't get your hopes too high on this; I asked support specifically about that and the answer I got was: it's only volume compensation for multiple subs receiving the same signal. For example, a Y-cable from 1 sub out on your AVR.

Yeah I suspected this might be the case as they don't provide any info about the calibration process being different. The old manual SPL gain compensation you had to do was embarrassingly silly though so I'm glad they fixed it.

 

[Sparky]

But what does the quote mean? In the time of analogue subs, having two daisy changed requieres reducing the level by 6db each... Does it do only this?

Or do they also measure the accoustic sum of the two sub responses to flatten this out? I'd be curious...

This is exactly what I need an answer to otherwise, dual Genelec subs (unless running them as a stereo pair) is completely pointless and I'll cancel my order before they arrive.

 

[Zaireeka]

This is exactly what I need an answer to otherwise, dual Genelec subs (unless running them as a stereo pair) is completely pointless and I'll cancel my order before they arrive.

I do believe the opposite is true, the best configuration being 4 subs but only for a marginal upgrade from putting 2 subs mid-walls. I'll for sure buy 2 Genelec 7350s later for my system instead one 7360. Better bass for the same price...

https://www.harman.com/documents/multsubs_0.pdf

 

[Sparky]

I do believe the opposite is true, the best configuration being 4 subs but only for a marginal upgrade from putting 2 subs mid-walls. I'll for sure buy 2 Genelec 7350s later for my system instead one 7360. Better bass for the same price...

https://www.harman.com/documents/multsubs_0.pdf

I'm well aware of the benefits of multiple subwoofers, 4 being the optimal amount in a rectangular room but, I have a wife and two kids so 4 subs is never going to happen in our lounge!

I've been using dual.subwoofers for years with a minidsp SHD. They have been painstakingly aligned with REW's alignment tool with a bit of help from the folks at AVForums (USA).
It took over a year to learn how to use it confidently and I'm proud of it.

I bought two 7360's in the blind hope that GLM will just auto-fix them for me and do away with all the messiness of having to align them etc etc.
The hardest part is choosing the correct x-over if I'm honest.

We are building a media wall so that's why I opted for the dual 7360's by the way. Saves me going through all the alignment again. Looks like I might have to though if GLM can't align them.

 

[Pekka Perämoottori]

GLM detects & measures loudspeakers + subwoofers present in GLM network, applies filters, delays and gain compensations.

If done properly, as can be assumed when GLM does it, subwoofers acoustic sum should already be pretty optimal. No need for further manual REW + UMIK -tinkering, measurement and especially interpretation errors. GLM knows what it is doing.


GLM is advanced and robust measuring-AI, outperforms 99% of REW + UMIK -amateurs on machines cold routine: it uses calibrated mic, its measuring routine and measurement interpretation are bullet proof. It wont make stupid, amateurish human errors.

No human errors means in practice: GLM´s mouse hand won´t begin to shake and lower lip to tremble in uncertainty when it tries to google / search from internet forums how other amateurs have set their filters.

So, you should just trust GLM´s judgment. It´s most advanced measuring-AI available. Your job is only place mic properly, run AutoCal and stay away / silent when GLM measures.

 

[Zaireeka]

I'm well aware of the benefits of multiple subwoofers, 4 being the optimal amount in a rectangular room but, I have a wife and two kids so 4 subs is never going to happen in our lounge!

I've been using dual.subwoofers for years with a minidsp SHD. They have been painstakingly aligned with REW's alignment tool with a bit of help from the folks at AVForums (USA).
It took over a year to learn how to use it confidently and I'm proud of it.

I bought two 7360's in the blind hope that GLM will just auto-fix them for me and do away with all the messiness of having to align them etc etc.
The hardest part is choosing the correct x-over if I'm honest.

We are building a media wall so that's why I opted for the dual 7360's by the way. Saves me going through all the alignment again. Looks like I might have to though if GLM can't align them.

Are you going to set them in mono or stereo config? I've read that mono is the way to go, I'm also curious to get your feedback on the new GLM subwoofer management functionality.

 

[Sparky]

GLM detects & measures loudspeakers + subwoofers present in GLM network, applies filters, delays and gain compensations.

If done properly, as can be assumed when GLM does it, subwoofers acoustic sum should already be pretty optimal. No need for further manual REW + UMIK -tinkering, measurement and especially interpretation errors. GLM knows what it is doing.


GLM is advanced and robust measuring-AI, outperforms 99% of REW + UMIK -amateurs on machines cold routine: it uses calibrated mic, its measuring routine and measurement interpretation are bullet proof. It wont make stupid, amateurish human errors.

No human errors means in practice: GLM´s mouse hand won´t begin to shake and lower lip to tremble in uncertainty when it tries to google / search from internet forums how other amateurs have set their filters.

So, you should just trust GLM´s judgment. It´s most advanced measuring-AI available. Your job is only place mic properly, run AutoCal and stay away / silent when GLM measures.

I totally agree with your comment.
I have, over the years, used a number of "room correction" products including DIRAC, Anthem Room Correction, Room Perfect and Audysey and none of them have come close (in my humble opinion) to what GLM does.
Before I owned my first set of Genelec SAM monitors, I was continually measuring my room almost on a weekly basis trying to find that "perfect sound" and I never found it after over 15 years

Buying the 8341's and running the first GLM measurement was all I needed.
I've been 100% satisfied with the outcome knowing that GLM has done its job.

With regards to the subs, there are obviously things that GLM can't do like boost a null and that's where good subwoofer positioning comes into play.
unfortunately, most of us have to make compromises here and our subs and monitors are not ideally placed.

 

[Sparky]

Are you going to set them in mono or stereo config? I've read that mono is the way to go, I'm also curious to get your feedback on the new GLM subwoofer management functionality.

Definitely mono. I plan to run them as one sub aligned together as one.
I intend to choose the closest monitor to them both and use that as an acoustic reference.
That monitor will also be used to select an appropriate crossover.

 

[Pekka Perämoottori]

For those multiple subwoofers craved bass-response -smoothing properties to work & realize, it´s most essential that all systems subs reproduce the same acoustical signal.

 

[Sparky]

For those multiple subwoofers craved bass-response -smoothing properties to work & realize, it´s most essential that all systems subs reproduce the same acoustical signal.

Definitely. Multiple subs is all about a smooth response at the listening position by feeding those subwoofers with the same signal summed together as one.

I can tell you that, when done right, it sounds phenomenal. My two 12" sealed subs (not Genelecs) achieve a flat response at 19hz (90db) to the crossover point. Organ music is sublime.
You cannot localise either sub due to a crossover point lower than 120hz.