Genelec GLM in the living room

Update 1.4.2021:

Having used this setup for some time I a had came across some issues. For one, USB over IP client looses the connection every now and then. Simple restart helps but it’s annoying. Maybe running it as a service would help? Another one is that I couldn’t get calibration to finish with this setup. So I had to run calibration with a laptop, export the profile and then use it. Annoying as well, especially since I’m new with these speakers and found myself trying little changes and calibrating again couple of times.

So after all I gave it up and purchased one more Intel NUC. That allows similar install than with the previous one but with a local USB connection between the GLM and the OS.

I’m a Finnish engineer and simply cannot help being a huge fan of Genelec speakers. That said I understand those are mainly targeted to audio professionals, which I’m not. That fact didn’t stop me of buying a pair of those to my living room.

So I purchased a pair of “the Ones“, second hand 8351A to be exact. I like the looks. I like the combination of active speaker with digital input. I also like the point source design based on the coaxial elements. These combined results as a speaker that allows quite minimalistic setup with a sleek looks. And I’m now free to choose the listening position as close to the speakers as I want to go.

“The Ones”

Perhaps the most appealing factor to an engineer (remember my heading “engineer view to the world”) is the DSP capability built in. That means the speaker can adapt to the listening environment and more specifically to the listening position. Genelec has the “Genelec Loudspeaker Manager” (GLM) solution. It consists of a GLM network adapter and a calibration microphone. The network adapter is connected to the speakers in a daisy chain way with additional cat5 cables. According to Genelec this allows you to do the following (amongst other stuff):

  • “Automatically adjust in-room frequency response, distance delay and listening level”
  • “Switch between listening locations, including individual monitor time offsets”
GLM with Raspberry Pi 4

When you’re ready with the room calibration you can save the profile to the speakers. If this is the only thing you wanted, you can then unplug the GLM network and enjoy you’re setup. But if you’re like me, you have multiple reasons the keep the GLM connected all the time:

  • Volume adjustment at the speakers with the wireless remote
  • Switching between the profiles, for me mainly to the change listening location
Genelec GLM remote

Having the GLM connected is a small price for these possibilities. What makes the problem, is that changing the profile requires also active connection to the computer running the GLM software. I don’t have computer set up in my living room and I’m not planning to have one. So there must be some way of getting around this requirement?

My solution is running the computer elsewhere (in my case as virtual) and connecting the GLM adapter there wirelessly. The connection from the GLM adapter is only USB so that means running USB over the network. There are some commercial solutions available like the one from Digi (which I haven’t tested for this purpose). I decided to give a try for an open source solution, this time usbip running on a Raspberry Pi 4. This way I have wireless USB over IP connection between my GLM adapter and the virtual computer running the GLM software.

As an addition to that setup I realized that I have a TV that has a RDP client. So now I can both use the remote with full functionality and also see the GLM screen. Seeing the GLM screen helps mainly knowing which profile is currently active. I have no need to control the software on a daily basis, so there is no need for a mouse or a keyboard. When I need to do some changes, I can easily connect my laptop to the RDP session to be able to control the software.

My setup does what I need perfectly. Even so, it includes external software and additional setup. It makes me wonder if it would be possible for Genelec to store at least some number of profiles in the GLM adapter to allow changing between those without computer being attached? This kind of lightweight solution would be good enough for me even without a screen to display any information.