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Genelec 8320 REW measurements with and without GLM

GD Fan

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This post is a big step for me, involving two things I was completely unfamiliar with prior to finding this outstanding website: REW measurements and room correction. Having overhauled my main system only mere months before stumbling upon the enlightenment of ASR (the system sounds great but no doubt certain things would have been done differently), I vowed to incorporate as much of the excellent advice and expertise here as possible when revamping my desktop rig.

That led me to the Genelec 8320 speakers. These were chosen based on the favorable research on and recommendations of Genelec, the GLM module, and their size. My home office is in a fairly small second bedroom in my Manhattan apartment, and my desk is correspondingly small. The rear ports stand but 6 inches from the front wall, and the listening position is really close (my eyesight sucks and I stare at a computer monitor all day). The rear wall is only about 5 feet behind. Source is Dell XPS desktop (hard drive files and Tidal)->Topping DX7Pro->Genelecs. No subwoofer. Here's a photo:

Desktop rig.jpg


The mixed iconography of St. Louis Blues and Green Bay Packers logos on the desk may seem incongruous. To make it odder, the truth is I have never lived in either place!

Anyway, here's the REW graph of the speakers before the GLM room correction module arrived. Note this is the average of 4 measurements, VAR smoothed. Two measurements were from center MLP, and one each to replicate "leaning" left and right. Considering the rather extreme nearfield application this struck me as sufficient. I'm also new to this.

Genelec 7.1.20. average no GLM or stands.jpg


You guys certainly know better than I, but this struck me as a pretty good outcome. The high end is really flat and the upper bass less jagged than expected. The absence of a sub is quite apparent, as expected with 4" woofers, and there's a funky room mode at 250Hz-350Hz, but it isn't a major disaster. This left me wondering if it had been worth the marginal expense for 8320s over 8020s PLUS the extra cost for the GLM module.

Here are the results with the GLM freshly installed today. Same setup in every other regard. Note the Genelec desk stands were a special order that will arrive next week. New measurements will be taken, but who knows what, if any, difference they will make.

8320 AVERAGE with GLM no stands.jpg


Apparently that 250-350Hz zone was a little tough to clean up entirely but it's been reduced a bit. And the downshift from 850-1300Hz has also been reduced. Highs are still pretty flat, probably more so on average.

Is the difference noticeable? It sounds great, subjectively, but it sounded great without the GLM correction. I wouldn't claim to have trained ears, and don't feel at all knowledgeable of what a speaker "should" sound like. But the simple fact that there's no wondering what-if probably makes it worth the up-charge over the 8020s. Upgraditis is a terrible thing...

Anyway, sorry for the long post. Hopefully it is useful to someone. Any critiques or criticisms will be welcome and well received - there are no doubt some improvements to be made to the technique here.
 

echopraxia

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GLM and EQ is especially amazing in difficult rooms, like mine. I posted some screenshots of the GLM results elsewhere but I don’t have them handy now, but prior to GLM there is no good speaker position in this room. Either huge 20db bass and midbass nulls everywhere, or massive resonances throughout the bass creating a muddy boomy sound.

Now I have them on stands as near to the walls as they can be, where they take advantage of room gain, which GLM then equalizes that muddy boosted sound to very nearly +-3db down to 25hz. The difference is huge. Then I apply a downward sloping target curve because otherwise my in-room curve is too bright (since GLM calibrates to a flat in-room curve otherwise), after which it sounds as perfect I can imagine for a small room with such poor acoustics.

It’s the best bass of any room I have now, despite being the worst prior to EQ.

Now I need to figure out how to EQ my other rooms with passive speakers that are not connected to a PC. So many DSP choices to considers there, each with their pros and cons and setup complexity. GLM makes it so easy, in comparison.
 
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_Bass

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Your setup looks awesome! Really thankful that you sharing your measurements. For most people getting a SAM speaker is too expensive, and there is quite a it of cabling involved with the GLM setup

I am personally surprise that GLM equalized above 1k Hz as the response there was pretty flat. Would have expected to not touch the highs. Is there a way to limit GLM to certain frequency?

Looking forward to your next measurements with stands. If you could keep all plotted lines in one graph would be even nicer :)
 
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As far as I know, yes. You can adjust all PEQs manually afterwards.
 

echopraxia

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Your setup looks awesome! Really thankful that you sharing your measurements. For most people getting a SAM speaker is too expensive, and there is quite a it of cabling involved with the GLM setup

I am personally surprise that GLM equalized above 1k Hz as the response there was pretty flat. Would have expected to not touch the highs. Is there a way to limit GLM to certain frequency?

Looking forward to your next measurements with stands. If you could keep all plotted lines in one graph would be even nicer :)
For me at least (I’m not OP), GLM does not touch the high frequencies automatically. And I don’t see anything really changing above 1k though in the plots above. But yeah, you have full control of the filters yourself as well.

Regarding wires, it actually can be simpler than most external DSP solutions because once you’ve calibrated the speaker to your liking, you can store the calibration on the speaker itself and unplug GLM network cables etc., if you want. You just need to flip the switch on the back instructing it to use the stored settings, after saving to the speaker via the GLM software.
 

mkt

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Gorgeous! Great choice of equipment! I have 8320's, a DX7Pro, and a much messier desk :)
Listening/measuing position about 1m. My computer monitor is even closer to me; the speakers are a little behind it.

Here are single REW measurements left, right, and left+right averages. The sub is a 7350. The "Sound Character Profiler" in GLM is set to "none", no roll or HF tilt.
Right-8320.png

Left-8320.png

Right+Left-8320.png
 
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As another poster already stated the GLM wiring can be removed once the settings are stored in the speakers, which does help tidy up the desk. And it's a good point about adjusting > 1kHz, I will look in to that and see if it shows if & how much it has done. This was my first pass with GLM and based on the length of the manual (~85 pages) there's still much to learn!
 
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GD Fan

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The Genelec stands finally arrived. After wrestling with some minor issues (once on the stands the GLM cables are rather difficult to insert, etc) some more measurements were taken. So this is the final set up - with the GLM module and on the stands. Here's the new look:


Desk with Genelec stands.jpg


The same approach was taken with the measurements as in the original post. The comparison below is the average of the four measurements on each hardware, the rubber iso-pods and the desk stands.

8320 w GLM w and wo stands.jpg


The green is the average on the rubber iso-pods, the red is with the desk stands now installed. Note that not only is the height different so is the angle of the speakers. I was a little disappointed with the new rise from ~1k to 2kHz but perhaps the total effect is a flatter overall deviation from the mean above 1k?

There was a question after the original post about GLM above 1kHz. In fact the results do show the GLM filter in play up to about 1250Hz.

GLM graph.jpg


Obviously a subwoofer would help a lot. But my home office is both above and below bedrooms in the apartments on the corresponding floors so I am fighting the temptation in the interest of peaceful neighbors. The price of the Genelec subs also helps resist... But the graphs that mkt posted above with and without the sub and GLM show some impressive results with that combo!
 

mkt

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They look nice! Are they level with your ears? My impression was that they might be a little low on a work desk (as opposed to a mixing desk with a higher rear level).

For listening (not mixing or whatever), my impression is that, depending on the material, there's not that much down there that you are missing. The other side of that would be that if you add a sub, the neighbors would seldom notice.
1594601300380.png
 

soundwave76

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Good stuff! Those new Genelec speaker stands are awesome. I also use them with 8331. Sub will definetly improve your system sound A LOT. I have the smallest Genelec SAM sub (was it 7350) in my smallish home office room and it works great.
 
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GD Fan

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They look nice! Are they level with your ears? My impression was that they might be a little low on a work desk (as opposed to a mixing desk with a higher rear level).

For listening (not mixing or whatever), my impression is that, depending on the material, there's not that much down there that you are missing. The other side of that would be that if you add a sub, the neighbors would seldom notice.
View attachment 73074
You're exactly right, the stands actually leave the speakers a little low. While that is slightly disappointing the clean, uncluttered look means that's how they'll remain. Plus the upward tilt is pretty minor. It may be worth pointing out, for the benefit of anyone considering buying the stands, that the angle adjustment mechanism is somewhat imprecise and made it a little difficult to dial them in to the same angle.

Your chart suggests I might benefit a fair bit from adding a sub - gotta hear Phil Frazier digging deep on the tuba with Rebirth Brass Band!
 
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test1223

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They look nice! Are they level with your ears? My impression was that they might be a little low on a work desk (as opposed to a mixing desk with a higher rear level).

For listening (not mixing or whatever), my impression is that, depending on the material, there's not that much down there that you are missing. The other side of that would be that if you add a sub, the neighbors would seldom notice.
View attachment 73074
Hello,

these tables of the frequency content are misleading. It often represents the fundamental frequencies, but if you have a look at actual recordings, the bandwidth which you need to record everything transparent is much larger. Have a look at plosives like the p or t you need more or less the whole audio band for it. Even the very low bass is needed if your SNR at the listening position is high enough and the microphone / mix caputures it correctly.

Best
Thomas
 
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