Genelec’s recently announced upgrade to their GLM speaker calibration system for SAM monitors. GLM 4.1 has the new AutoCal 2 algorithm which promises better, faster results. Find out what Julian thought in our On Test article.

Genelec’s GLM+SAM monitoring systems were the first place I encountered any kind of speaker calibration system all the way back in 2011, paired with some 8250A monitors. The early incarnation of the GLM software available back then was a rather joyless place of light grey windows with graphs with traces in primary colours on white backgrounds. Software designed by scientists for other scientists.

Arguably the appearance of software shouldn’t matter but to most people it really does and I’m glad to say that the modern incarnations of the Genelec Loudspeaker Manager are a much more pleasant place to spend your time, both in terms of the appearance and more importantly operation. Of course what really matters is what it sounds like and I’ll get to that but it has been a long time since I last tried GLM and until trying GLM 4, I was of the opinion that in terms of ease of use Sonarworks were the people who had the best user experience. Having tried GLM 4 I now think Genelec have got this nailed. It’s an absolute joy to use.

GLM 4 offers the automated measurement and calibration we expect but manages to keep the flexibility which can so often be compromised when you automate a process. If you just want to take a single point measurement for some stereo monitors and get to work, you can be up and running in not much more time than it took to read this sentence, not including the time it takes to connect the GLM kit, measurement mic and network cables.

The 4.1 update is much the same as version 4 in use but the improvements are “under the hood” and are firmly aimed at getting something which already sounds great, sounding even better. Before getting to the results of these improvement it is necessary to get set up.

Setting Up GLM 4.1

The GLM network Adapter Kit (around $300) is a necessary part of this system as well as the free software and of course a pair of Genelec’s Smart Active Monitors (SAM). The procedure is to connect the Genelec Network adapter hardware to the host computer via USB. The supplied measurement mic is connected to the network adapter via mini jack and all the SAM monitors in the system have to be connected to the network adapter via standard ethernet cables.

Once the connections are made the software needs the serial number from the measurement mic so it can retrieve the frequency response of that particular mic from the cloud. This is the first example of data being retrieved from the cloud but won’t be the last.

One of the great things about GLM is that it is very, very simple to use but it scales to the largest of Dolby Atmos monitoring environments and allows considerable user control. I’m using it in a very simple application, with two 8331A SAM monitors. However I’ll be using the Groups function to help with my particular setup.

The monitoring system is represented graphically on a grid of hexagons, allowing the physical arrangement of the monitors to be reflected in the UI. Something which initially confused me is that while discovery of all connected monitors is automatic, they all appear stacked in a single cell of the hexagon grid. I initially thought that the software had only found one monitor but I just had to move the top monitor out to another cell and the next monitor is revealed underneath!

After arranging the monitors, calibration couldn’t be simpler, Create and name a Group and select the measurement you wish to take, single point or multi-point. A single point measurement at the listening position improves things enormously over the uncalibrated sound but considering listening with two ears is a multi-point experience there seems little to be gained from not completing a multi point measurement.

In some systems a long multi-point measurement process has to be completed and I do question the advantages of taking measurements over a wide area, particularly from points in the room from which I will never listen critically. GLM allows you to choose the number and location of your multi-point measurements. I took 7 at multiple positions around where my head would be - the standard swept tone process you might have experienced with other systems.

After the measurement is taken the software accesses a database of measurements in the cloud to determine the best settings for you particular measurement. This is where the principal new feature of GLM 4.1 comes into play. The new AutoCal 2 algorithm delivers more precise results in less time. The reference to less time might surprise you if you haven’t used GLM before but in the previous version it was noticeable just how long the software took to compute the results. AutoCal 2 is noticeably faster.

Using Groups

I have been using a sit/stand desk for about a year and as a result have changed my priorities when it comes to monitoring, as a good monitor in the wrong place is no longer a good monitor! I have tried various monitors mounted on suitable stands on my desk rather than on my floor stands so that they move with me when I change from sitting to standing. I’d dusted off my old Genelec 1029a’s as they were ideal in terms of size and weight in this application, however 20+ years is a long time in monitor design and there are better sounding options out there.

The better sounding option I’m using here are the absolutely magical 8331A SAM monitors, the smallest of the Ones series from Genelec. These tiny three way coaxial monitors are a modern day equivalent of the 1029a and the jump in performance is startling to say the least. Straight out of the box these monitors sound great. Like really great. I’m not going to qualify this with “for their size”. These sound great, period.

Once calibrated, the difference is startling but elusive. Unfortunately there is no way to talk about this without falling back on the same old adjectives: “focused”, “together”, “tighter”, “revealed”. You get the idea. Like all of these things the difference is more noticeable when turning it off than turning it on, suddenly the stereo image becomes more vague, sounds which previously were absolutely planted in the stereo image suddenly lose their definition. And the bass is just “better”. It’s not subtle!

Sitting Or Standing

This was in the sitting position but at the push of a button I could raise my desk, monitors and rack. However by doing so my monitors and ears are in a completely different position. This is where the Groups in GLM come in. By taking measurements in both sitting and standing position and saving them as groups I can switch between the two calibrations making sure that my monitors stay correctly calibrated. It’s also a good opportunity to see which position is acoustically preferable.

The plots showing the measurement data and the filter settings are easily accessed from GLM by right-clicking on each speaker and selecting Acoustic Editor. In here you can manually adjust the filters if you choose to, though personally I’d leave it to Genelec, and the software offers several other features beyond just switching calibration on and off. If connected digitally you can set up calibrated monitor levels and because the UI is properly scaleable, if you resize the window to a tall, narrow window you can use GLM as a software monitor controller, with the grid of hexagons no longer displayed.

Be aware that when you power up your monitors are muted, just un-mute them in GLM, this caused me some head-scratching the first time it happened, and while I preferred to leave the monitors networked and the GLM Network adapter connected permanently you can of course store your Group preset to your loudspeakers for truly transparent operation.

So which position is the best according to the measurements? Here are the plots and you can see that the results between sitting and standing are dramatically different. Standing looks to be the best option and this suits me as I spend most of my time standing. My room is new to me and is about to undergo some quite serious alterations before acoustic treatment goes in so it is an ideal test for one of the target audiences for GLM - people working in less than ideal environments, often only temporarily. I would be very happy to take such a compact set of monitors to a temporary tracking space, something I’ve used my 1029a’s for many times in the past.

GLM 4.1 has taken an already great product and improved in in he most important way they could have. It’s more convenient to use and sounds better courtesy of AutoCal 2.

Pros

• I’ve not heard a better Speaker Calibration system

• Easy to use

• Offers deep control if you want it

• Can upload settings to SAM monitors or run via software

• Free software, though you need the SAM monitors and Network Adapter Kit

Cons

• Only available to users of SAM monitors - not really a criticism but I wish I could use this with my other monitors.