My Analog mixer Studer 928 has left channel a bit louder than the right in the master bus

[Primary perception music]

Hi folks!

Some guy in Soundandsound recommend me to post this thread here on Homerecordings. Already that difference between left side and the right side of my master section is not a problem that its completely normal but I would gladly read your comment in order learn more about it. I copy the description of the post. Also I would like to know which is the audible difference between the both side for human ears in dbs.

The post I did, here is the copy of the description I put on Soundandsound;

Today doing some checking of my new analog mixer I realized that the left channel of master bus is louder right exactly 0.2 rms and 0.4 peak. I knew that when I did some checks on my daw with a meter plugin but for my ears the stereo was in the center.

Do you think this is normal in analog mixers or Do I have to bring it to the technician for a proper calibration?

Thanks

 

[sweetbeats]

Greetings.

We need more information to help.

Your post leaves a lot of questions not answered.

0.2 RMS and 0.4 peak…what…? Volts? Decibels?

What type of test signal? Sine wave? White or pink noise? If sine wave what frequency? And what is the source of your test signal? The oscillator onboard the Studer? Or an external source connected to the Studer? If an external source how did you connect it to the Studer?

And how did you measure the discrepancy? What meter are you using and did you measure at the outputs jacks of the Studer or are you saying you used some metering in your DAW to measure? If you used the DAW how do you know the Studer is at fault? You have cabling and an interface in between. It could very well be the Studer, but your post leaves all this to question. If you used the DAW to measure, did you swap cabling at the interface and then at the console to isolate and verify the source of the discrepancy?

Again, maybe you did all these things, but it’s not clear from your post, and before I start trying to answer your question I really need to know what exactly we’re talking about here, where the issue actually originates, what unit of measurement we are talking about, and how you measured.

 

[ethyrvalve]

Just to add to what Sweetbeats posted... assuming your measurements are accurate, these Studer desks have excellent service manuals and many adjustment points. If you're not comfortable doing the calibration yourself, this would likely be a very easy job for a competent tech.

 

[Primary perception music]

Hi guys,

Thanks a lot for your reply.

I did the metering with a meter plugin inside of my DAW using a kick from drum machine connect it to a mono of the mixing console and then meter the master bus. Actually the peak shows 0.3 and finally after reading your comments, some info internet I realize that 0.3 is so little to worry about, also because my ears tell me that the stereo was ok. The console was full recap and calibrated from good tech here in Berlin at the same moment we received after purchased. It was just checking if the console is in full spec.

Sorry for all the misunderstanding english is not my mother language and sometime I cant make myself clear.

Thanks for all the info

Best

 

[sweetbeats]

I really wish you would share the type of units of your measurement…the “0.3”. Is that dB? Volts?

To properly check a master module output you should use the onboard oscillator, and measure at the master output jacks at the console with an appropriate level meter. You have too many variables in your signal chain to judge the balance of the master outputs: the output from the mono input module through the motherboard to the input of the master module, your cabling from the master module to your interface, the input and signal path of your interface, etc.

 

[Primary perception music]

Sorry forgot to say the type of measurement, It was DB.

I would do the measurement with the onboard oscillator tomorrow when I will be back in the studio

 

[rob aylestone]

First point is that you never make measurements with a kick drum - impulse measurements will include the ballistics of the meters, even digital meters vs real moving meters. You need a continuous tone. 0.3 is as close to 0.0dB as you probably need to worry about, and most humans struggle to accurately detect changes of 2dB unless they are very abrupt and at a higher frequency. Often, you can see these things and then your brain convinces you that you can hear them. 0.3dB is tiny movement of the faders. Personally - I consider it close enough to not remotely worry.

 

[sweetbeats]

First point is that you never make measurements with a kick drum - impulse measurements will include the ballistics of the meters, even digital meters vs real moving meters. You need a continuous tone. 0.3 is as close to 0.0dB as you probably need to worry about, and most humans struggle to accurately detect changes of 2dB unless they are very abrupt and at a higher frequency. Often, you can see these things and then your brain convinces you that you can hear them. 0.3dB is tiny movement of the faders. Personally - I consider it close enough to not remotely worry.

+1 to every bit of that. @Primary perception music I realize you already came to that conclusion, but Rob’s point about impulse type signals and meter ballistics vs constant tone is something I meant to mention too, and he’s 100% correct.

 

[Primary perception music]

Thanks a lot for your reply!
Yes, I think I have not to worry about it.
I did a test with 1K sine wave tone generator that comes with the Studer. I attach a picture with the results.

 

[Primary perception music]

Some people in other said that in a full track 0.1 can be perceptive, for example in mastering. To be honest doing some test exercise with the app somo soundgym I cant barely notice a different of 0.5 between two tracks. I dont know if happen the same with L/R difference or maybe my ears are not trained enough yet.

 

[Primary perception music]

I will attach the comment right below. I would like to know your thoughs about it.

 

[rob aylestone]

Most people cannot detect 2dB! Analogue kit lineup was always a sort of art, looking for the best compromise between every factor that always seemed to fight with each other.

In practice, with any stereo, or psuedo stereo source like synths and complex layered samples - sum and difference creates far more repetitive difference between left and right. On old real meters with real ballistics, these were rarely visible but with LED meters and on screen meters we see the imbalance far easier. For interest I just tried the system here, which has near field meters and I can pan a tone a fair way before I can hear it move, but I can see it straight away. With your reel to reel, and I'm guessing the inputs coming up on two fares one left one right, without looking at the meters, how far do you go on the faders before you detect the shift. I seriously doubt that tiny difference could be heard before you see it?

 

[Primary perception music]

Honestly I cant hear the difference, I try with my monitor with a really good headphones and same I cant hear it. Dont know if anyone can but me not for sure and I doubt someone can as other people said like the story of Donald Fagen. I put the faders on 0 and master the same. I just commented what other people said in others forum.

 

[rob aylestone]

Joking aside, but I'm pretty certain the gain om my Midas M32 is a bit lopsided on the USB audio playback. the meters are never exactly the same. I can't hear it of course, but I can see it!

 

[sweetbeats]

At the end of the day, if you want the right and left outputs to match, just follow the output calibration instructions in the manual…page E 3/21 in the Alignment section. You can do it with the onboard test tone generator and any unbalanced RMS reading voltmeter that is accurate at 1kHz. You don’t need the extender boards (bus adapter) depending on where your master modules are loaded in their bucket of the frame, but usually the master modules have plenty of slots to the left in the bucket before the wall, so you just pull the modules to the left of the master modules out, enough that you can get your trimmer adjuster in there and follow the instructions. But also I would y be concerned about what you are seeing difference-wise between the two outputs. But like I mentioned before, to do it right you need to be measuring at the module, because it’s possible for cabling and the inputs of your DAW interface to introduce discrepancies.

 

[Primary perception music]

Some a bit scary to me. Im not a technician. Reading all your comments I should not worry about it. Im planning to use the mixer as summing and for routing all the outboard gear. In case you told me is not healthy to do mixes with that difference Im going to leave it like that, also because the tech who fix and do the all calibration of the console is expensive.