Genelec GLM Review (Room EQ & Setup)

[Masza]

It just seems to me like trying to force yourself to do things the hard way just because you paid extra money for a system that included EQ. I've read where people did this--I think there is even a topic on this site--and I just couldn't understand why they were willing to go to the trouble. But maybe they (and you) just like the challenge. Nothing wrong with that.

I wouldn't do it if I had SAM Genelec speakers and subwoofer. But if I had an SVS sub I would definitely use its DSP and integrate it to SAM Genelecs with its phase setting or with the delay setting of the audio source. I can see why people buy SAM Genelecs and a subwoofer by another manufacturer, at least for LFE use.

 

[Steve Dallas]

No, Amir is not saying that, but it’s pretty obvious that the default Audyssey curve contradicts current Harman research and B&K research from the 70’s. Why should the default curve be so bad that I’m forced to use an awkward, imprecise touchscreen interface to try to work around it?

I bought a $20 bluetooth mouse to make it easier to adjust the curve. I also limit its correction to below 1KHz.

 

[Walter]

I wouldn't do it if I had SAM Genelec speakers and subwoofer. But if I had an SVS sub I would definitely use its DSP and integrate it to SAM Genelecs with its phase setting or with the delay setting of the audio source. I can see why people buy SAM Genelecs and a subwoofer by another manufacturer, at least for LFE use.

I agree on both points. The Genelec are excellent speakers whether one uses the GLM or not, but their subs seem like poor value (but very good if the cost is not a factor). When the sub ALSO has built-in EQ like the SVS, that probably tips the scales against using a separate system that can work on both, in my opinion.

 

[phoenixdogfan]

"Sadly as with all of its competitors sans JBL ARCOS, the corrected response is a simulation. No post calibration measurement is performed to see if that is the results that is generated. "

A shame. My DL3 measurement with proposed correction shows utter perfection. Would be nice to have an actual measurement from Dirac to verify that though in all fairness, I don't see how it could generate the corrected signal and actually measure it given that its correction is based on 17 measurements and the correction curve can only be calculated after the measurements are complete.

If it allowed a second set of post correction implemented measurements, it would be necessary to place the mic in the exact same place for each of the 17 measurements to achieve a properly accurate comparison--a level of precision I have neither the inclination nor ability to achieve.,

 

[Trell]

I agree on both points. The Genelec are excellent speakers whether one uses the GLM or not, but their subs seem like poor value (but very good if the cost is not a factor). When the sub ALSO has built-in EQ like the SVS, that probably tips the scales against using a separate system that can work on both, in my opinion.

Yeah, the Genelec subwoofers are expensive but for me the 7360A was very handy to pair with my 8330A for my 2.1 desktop system: The calibration is stored in each monitor/subwoofer, no need for an extra box to handle bass management or special DACs. A simple setup that works very well with GLM and it's calibration.

As for use of GLM with non-Genelec subwoofers the possibility to set a high-pass filter for each monitor should help with the integration. The Genelec high-pass filter is quite steep at 48dB/octave.

 

[Blake Klondike]

This is a review and detailed measurements of the Genelec GLM "SAM Loudspeaker Management System." Its main use is automatic and manual room equalization for select Genelec speakers with such support. It is on kind loan from a member and costs US $299.

I was pleased to see it come with a nice looking microphone and an audio interface:

View attachment 151754

At first I thought the communication was through Ethernet so plugged in the speaker into my home network but nothing happened. Then I read the manual. I realized that the RJ-45 is a custom connection and protocol for the above adapter to talk to speakers in a daisy chain manner. Once I plugged the speaker into it, the GLM software recognized it and I was able to configure it. FYI the version I tested is the 4.1.

The interface is a bit tricky in that you have to drag and drop the speaker onto this unusual grid to then group speakers and manage them:

View attachment 151756

Post calibration to see how the filters are setup, you need to click on the Genelec speaker icon in that grid which was not easily discoverable. I found it by accident.

For testing, I used the Genelec 8330A which I had recently reviewed. The process could not be simpler. You tell it to start calibrating and next thing you know, this super loud chirp signal plays and that is that. No multiple measurements. No averaging. I would have wanted some control over volume on this but I did not realize the role of the vertical slider until later. The good news is that the whole affair was done in just a few seconds. Compare this to automated Room EQ on AV products that can be very time consuming with multiple measurements and such.

Before I show you the measurements, I really appreciated a couple of other cool features. First, you can calibrate the SPL level where you sit with the microphone. Once there, you can then leave the microphone there and watch the real time SPL values shown at the bottom level ("77" in this snapshot). I was able to go into low 90s before the speaker clipped with the speaker icon turning red above that. With all other systems, once you are done calibrating, the mic and software collect dust. Nice to see that is not the case here especially if the displayed SPL values are correct.

You can also preprogram a couple of SPL values as you see on the left. Once again, I could not discover how to change them. There are presets for the system/speaker but I could not figure out how to edit them.

The whole interface is very responsive which makes the included volume control slider useful.

Gelenec GLM Room EQ
The main event here is how well the automated GLM calibration performs. Per above, post correction you can examine what it did and thereby also understand its underlying technology:
View attachment 151757

I truncated the above display as it goes to 16 filters. The system is not different than automated filter creation in Room EQ. The system is simply using a combination of shelving and parametric EQ to build an inverse of the response with some care. For example, the sharp dip around 80 Hz which is caused by cancellation, is left alone sans a constant boost provided by the shelving filter. On the other hand, the peak at 200 Hz is attacked strongly with a complex curve created out of a nearly a dozen filters to invert it. The filter response is in blue and the measurement is in red. Filter applied to measurements is the green.

From what I can tell, it didn't attempt to make any correction above 300 Hz which is fine but then there is a lonely filter at 818 Hz with just a -0.3 dB gain. Such a filter will not have an audible effect. I wonder if it is using the knowledge of the speaker to make a tiny correction there?

Sadly as with all of its competitors sans JBL ARCOS, the corrected response is a simulation. No post calibration measurement is performed to see if that is the results that is generated. That is left to us to mess around with another microphone and measurements software to use. Problem with this type of verification is that the microphones will be different as will the absolute positions so we can't do a precise determination. But we can get close.

I used my Earthworks measurement mic with my RME Babyface Pro FS in combination with REW software to make a before and after measurement. I used 1/12 octave smoothing to keep detail there but soften the results some so we can make sense out of it:

View attachment 151759

Please ignore the levels. They are not calibrated.

The graph in red is the measurement prior to calibration. We see the standard impact of the room causing similar dual peaks around 55 and 180 Hz as GLM software showed. There is also the same dip at 100 Hz or so. We have a peak between 400 and 500 Hz that was not in the GLM measurement but this may be due to me not matching the mic location.

It is interesting that the correction for the first peak around 55 Hz is almost not there and much less so than predicted by GLM software. I can't explain this other than the filter implementation not having the resolution it thinks it has. Maybe the Q should have been lower.

On the other hand, the second peak around 180 Hz is corrected well with a response that actually matches the peak for the 55 Hz one.

Genelec GLM Room EQ Listening Tests
Turning the calibration button on and off is very fast allowing for quick AB comparison and boy is this a stark comparison (as it usually is with Room EQ). Turning on the EQ instantly removed some amount of low frequency boominess but importantly, it brought the vocals forward which I really, really liked. Once you listened to the calibrated sound, you just did not want to go back to not having it.

One of the key benefits of the GML is that you have full visibility into all the filters and you can add your own and turn them on and off and see which version you like better. So I added a filter at 449 Hz to fix the third peak with a Q of 5 and gain of -3 dB. This was a subtle change but it brought even more clarity to vocals. What I was hearing then was stunning! The vocals in one of my reference and favorite tracks, Biscuits from the live album by Fink had a realism and fidelity that was just a joy to listen to:

There, I did the obligatory thing of putting in some music in a review! But really, it was just wonderful and showed how good these Genelec speakers are when you take out the impact of the room.

Note that the overall signature was somewhat bright as is typically the case when you take out the excess bass. Genelec provides dual shelving filter overrides to boost the lows and reduces the highs. This is limited 3 dB max correction however. I found the effect subtle even at maximum correction and wanted to have more room for adjustment.

Conclusions
The Genelec GML Room EQ is a straightforward automatic generation and execution of filters. This makes the system easy to understand and modify but perhaps takes out the mystique of something magical going on. I personally may take a shot at just programming the filters manually or measuring and then modifying. While I have accepted the fact that consumer EQ products don't want to provide transparency on what they have done, I wish a Pro product like GLM would make a post EQ measurement and show that rather than simulated, feel good but made up response. It would take just a few seconds. Heck, that measurement could be used iteratively to optimize the filters more.

As is though, the system provides 90% of what an expert could do on his own in almost an instant. The improvement is dramatic and you would be silly for not using it if you have a Genelec SAM speaker. Indeed any system used without an EQ is producing incorrect and far less than satisfying sound in your room. You must have an EQ strategy and if you can't provide it upstream, having it this easily programmed into each speaker is a great help for very little money.

Overall, I am going to recommend the Genelec GLM. It should be mandatory for anyone buying a SAM speaker that works with it.

----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Does anyone have a sense for what the least-expensive way to get into this system with or without a sub would be? It sounds like best-case-scenario

 

[Tangband]

The Genelec subwoofers are really good .
I would say at least as good as their monitors .

We have compared with very expensive REL:s and also SVS and the Genelecs in the same pricerange has, the way I listen , a better sound . A tighter, deeper bass with less distortion.
I was very skeptical in the beginning that Genelecs subwoofers could play at the same quality level as SVS , but then I have heard the 7050c and 7360 SAM and they are both better to play music than SVS PB2000 and REL S5.

The 7360 SAM can play VERY loud ( louder than SVS PB2000. ) and the 7050c can, despite the small 8 inch driver, play as loud and clean as bigger subs from other brands at the same pricerange.

Ilkka Rissanen is a genius at constructing subwoofers , - he was earlier the subwoofer constructor of hometheatreshack.

 

[HiFidFan]

Does anyone have a sense for what the least-expensive way to get into this system with or without a sub would be? It sounds like best-case-scenario

The least expensive SAM monitor is the 8320a. If you wanted to add one, the least expensive SAM sub is the 7350a.

8320a with GLM and volume control is $1,639 from Sweetwater.

 

[infinitesymphony]

No one is talking about the most important feature: the Terminator port.

 

[echopraxia]

The Genelec subwoofers are really good . We have compared with very expensive REL:s and also SVS and the Genelecs in the same pricerange has, the way I listen , a better sound . A tighter, deeper bass with less distortion.
I was very skeptical in the beginning that Genelecs subwoofers could play at the same quality level as SVS , but then I have heard the 7050c and 7060 SAM and they are both better to play music than SVS PB2000.

The problem with Genelec subs is that they’re just not that powerful for their size, while also being extremely expensive. For the price of one Genelec 7370 (Genelec’s 12” sub), you could buy four Rythmik F12’s (each of which are more compact sealed servo 12” subwoofers which approximately match the Genelec 7370 performance, including both sound quality and power).

I owned a few Rythmik F12’s, and they’re actually a bit smaller than even my Genelec 7360 (10” ported) sub, cost a fraction of the price, and completely outclass the Genelec’s capabilities in every dimension (power, depth, etc.)

The only appealing value of Genelec subs IMO is the GLM integration, and their very durable and robust build. Unlike most audiophile speakers, Genelec subs are built with professional use in mind, and so you can place them under your desk without any concerns at all about damaging them by accidentally kicking your foot into the driver cone, because all Genelec subwoofers have very robust non-removable metal grills built in In contrast, my Rythmiks were aesthetically nice glossy piano black with covers that were entirely aesthetic only, offering almost no physical protection at all.

For this reason, I do find Genelec’s subwoofers are a great (though overpriced) solution for a desktop sound system (the convenience of GLM, plus the durable build of their subwoofers). But they simply aren’t at all competitive with other subwoofers for most domestic rooms and certainly not competitive with other better options for home theater.

For example, rather than a single Genelec 7370 (12” ported), you will be far better off buying (for the same combined price) a Rythmik FV25HP (dual 15” ported) and a MiniDSP SHD for DSP, which includes Dirac. The results will be vastly superior in every way.

 

[amirm]

If it allowed a second set of post correction implemented measurements, it would be necessary to place the mic in the exact same place for each of the 17 measurements to achieve a properly accurate comparison--a level of precision I have neither the inclination nor ability to achieve.,

Yes and this is what I don't like about mutiposition EQ systems. You can't easily try different things because measurements keep changing on their own. JBL gets around this by using 8 microphones you place statically. Alas this makes it very expensive so they loan the gear to installers.

GLM could do it in this instance since it uses just one measurement.

 

[Tangband]

IMO SVS and REL just aren’t very good compared to other subwoofers like Rythmik, JTR, JL Audio, and yeah Genelec. REL subs have tons of distortion, while Rythmik, JTR, and JL Audio are all very powerful for their size, and very low distortion — which is pretty much all that matters for subwoofer sound quality. SVS are okay I think, but just don’t perform as well as similarly priced Rythmik or JTR subs.

I don’t know what distortion Genelec subs achieve since they don’t publish these specs like Neumann does, but I assume it’s very good.

The problem with Genelec subs is that they’re just not that powerful for their size, while also being extremely expensive. For the price of one Genelec 7370 (Genelec’s 12” sub), you could buy four Rythmik F12’s (each of which are more compact sealed servo 12” subwoofers which approximately match the Genelec 7370 performance).

I owned a few Rythmik F12’s, and they’re actually a bit smaller than even my Genelec 7360 sub, cost a fraction of the price, and completely outclass the Genelec’s capabilities in every dimension (power, depth, etc.)

The only appealing value of Genelec subs IMO is the GLM integration, and their very durable and robust build. Unlike most audiophile speakers, Genelec subs are built with professional use in mind, and so you can place them under your desk without any concerns at all about damaging them by accidentally kicking your foot into the driver cone, because all Genelec subwoofers have very robust non-removable metal grills built in In contrast, my Rythmiks were aesthetically nice glossy piano black with covers that were entirely aesthetic only, offering almost no physical protection at all.

The Rythmik subs seems very good , I havent listened to them, but I will, soon.

And yes, the GLM function in the 73xx subwoofers is a very necessary tool to get a good sound in your room.

 

[Chromatischism]

I bought a $20 bluetooth mouse to make it easier to adjust the curve. I also limit its correction to below 1KHz.

I would, but they don't show the measured response on the curve editor so you can't trace over it to maintain the same levels. This would be an easy enhancement for the Audyssey team.

 

[echopraxia]

The Rythmik subs seems very good , I havent listened to them, but I will, soon.

And yes, the GLM function in the 73xx subwoofers is a very necessary tool to get a good sound in your room.

Be careful when trying to compare subs by ear. Even the same subwoofer will sound dramatically different in different positions of the same room, even when calibration is used (but even more so when not).

Using DSP is definitely essential for any subwoofers to sound good, but note that GLM is not the only (or even best) of such solutions. As I mentioned above, you could buy both a MiniDSP SHD (Dirac room correction DSP) and Rythmik FV25HP (dual 15” ported subwoofer) for the price of a single Genelec 7370 (12” ported)! This will unquestionably achieve far better results than the Genelec option of the same price.

But if you go into a demo room attempting to judge subwoofers by ear, all you will most likely hear is just the differences of the room or the subwoofer’s particular calibration.

 

[Tangband]

Be careful when trying to compare subs by ear. Even the same subwoofer will sound dramatically different in different positions of the same room, even when calibration is used (but even more so when not).

Using DSP is definitely essential for any subwoofers to sound good, but note that GLM is not the only (or even best) of such solutions. As I mentioned above, you could buy both a MiniDSP SHD (Dirac room correction DSP) and Rythmik FV25HP (dual 15” ported subwoofer) for the price of a single Genelec 7360 (12” ported)! This will unquestionably achieve far better results than the Genelec option of the same price.

But if you go into a demo room attempting to judge subwoofers by ear, all you will most likely hear is just the differences of the room or the subwoofer’s particular calibration.

I have the opportunity to have a friend who always tries to get the best gear, regardless of price. So the two Genelecs ( 7050c and 7360*2 in stereo ) I have listened to has been perfectly installed in a home, not a store.

 

[enricoclaudio]

The problem with Genelec subs is that they’re just not that powerful for their size, while also being extremely expensive. For the price of one Genelec 7370 (Genelec’s 12” sub), you could buy four Rythmik F12’s (each of which are more compact sealed servo 12” subwoofers which approximately match the Genelec 7370 performance, including both sound quality and power).

I owned a few Rythmik F12’s, and they’re actually a bit smaller than even my Genelec 7360 (10” ported) sub, cost a fraction of the price, and completely outclass the Genelec’s capabilities in every dimension (power, depth, etc.)

The only appealing value of Genelec subs IMO is the GLM integration, and their very durable and robust build. Unlike most audiophile speakers, Genelec subs are built with professional use in mind, and so you can place them under your desk without any concerns at all about damaging them by accidentally kicking your foot into the driver cone, because all Genelec subwoofers have very robust non-removable metal grills built in In contrast, my Rythmiks were aesthetically nice glossy piano black with covers that were entirely aesthetic only, offering almost no physical protection at all.

For this reason, I do find Genelec’s subwoofers are a great (though overpriced) solution for a desktop sound system (the convenience of GLM, plus the durable build of their subwoofers). But they simply aren’t at all competitive with other subwoofers for most domestic rooms and certainly not competitive with other better options for home theater.

For example, rather than a single Genelec 7370 (12” ported), you will be far better off buying (for the same combined price) a Rythmik FV25HP (dual 15” ported) and a MiniDSP SHD for DSP, which includes Dirac. The results will be vastly superior in every way.

A BIG Mastering studio after upgrading all their subwoofers from Rythmik Audio to ATCs back in 2019, just purchased a pair of F15HPs again because they like our subwoofers better. The big advantage of Rythmik Audio subwoofers for mastering and mixing is that they operate in the analog domain so there is ZERO added latency, not to mention Direct Servo makes the sound more accurate and clean. You can find our subwoofers in recording and mastering studios around the world. My personal mastering subwoofer is a E22.

 

[q3cpma]

A BIG Mastering studio after upgrading all their subwoofers from Rythmik Audio to ATCs back in 2019, just purchased a pair of F15HPs again because they like our subwoofers better. The big advantage of Rythmik Audio subwoofers for mastering and mixing is that they operate in the analog domain so there is ZERO added latency, not to mention Direct Servo makes the sound more accurate and clean. You can find our subwoofers in recording and mastering studios around the world. My personal mastering subwoofer is a E22.

How do a few ms of delay matter when it's arguable negligible to group delay and/or cycle duration at these frequencies?

 

[Trell]

[snip]
For example, rather than a single Genelec 7370 (12” ported), you will be far better off buying (for the same combined price) a Rythmik FV25HP (dual 15” ported) and a MiniDSP SHD for DSP, which includes Dirac. The results will be vastly superior in every way.

Depends where you live what the price is or even if the product is available locally.

I got the Genelec 7360 subwoofer for my 2.1 desktop system and had to buy the GLM Kit as well, though that kit I also used to calibrate my wife's 2.0 desktop system. Can't say the same for the MiniDSP.

• Genelec 7360 (10" ported) + GLM Kit: 20 290 SEK + 3 599 SEK = 23 889 SEK
• SVS PB-1000 Pro (10" ported) + MiniDSP SHD + UMIK-1: 7 490 SEK + 13 998 SEK + 1 288 SEK = 22 766 SEK

Not exactly clear cut from a price point of view, and with the 7360A I do have an integrated solution.

 

[Robbo99999]

My thoughts after reading the review - it's a very simple system, indeed very much like REW and it's automatic filter creation abilities. To be honest, you don't need this GLM thing, the lack of complexity of it's process means that it can easily be equalled and bettered by using REW software and a UMIK microphone with a laptop to do your own measurements - this way you can do multiple measurements and average them to make the results more applicable, or you can even try different measurement methodologies like the Moving Mic Method (MMM), so it's a lot more flexible & creative to go down the REW & UMIK option rather than the more restricted GLM option in this review (it's actually not sophisticated or special in comparison). The GLM process is quite easy by the looks of it though, and there is more of a learning curve with using REW & UMIK.

 

[Robbo99999]

Mitchco,

I don’t think you’re going to change Amir’s response on this matter; this is a review to guide a purchase decision not a comprehensive discussion on room/speaker correction; as in your book

https://www.amazon.com/Accurate-Sound-Reproduction-Using-DSP-ebook/dp/B01FURPS40

Clearly amir has set it up as is and reviewed it for a single mic spot, which experienced users will understand that it accurate for one ear, but not the other. It is a quick and dirty “room correction” .

Users who have experienced room correction using products like Dirac or Acourate (almost a decade old now) know of their benefits of measuring over multiple points vs the single mic point correction, and using mixed FIR and IIR filters to correct for all frequencies; whilst minimising delays.

Be careful you may find yourself banned.

Thanks for the link there, I want to learn more about mitcho's process, so I've just bought this book right now & will be delivering it to my Kindle.