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

[Primary perception]

Hi everybody,

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

[Primary perception]

Forgot to mention. I did the check with mono kickdrum in a mono channel send it to the master.

[Wonks]

Have you tried this on different channels? It may be that it’s the pan control on that channel and other channels will give different results. The two carbon tracks on the balance pot will have some tolerance on their values, and for an analogue circuit, 0.4dB difference is pretty good!

[Primary perception]

Thanks a lot for your reply!

I only tested it in one channel, I will do the test on Monday.

Yeah I would be pretty good for analog because to my ears the difference were not audible and in VU meter was ok.

[ef37a]

Mr Sweetbeats is our resident TOTAL expert on Studer mixers but in the meantime you will have to put up with my meagre knowings...

You need a SINE signal source and any DAW can generate them including Audacity. I would choose a frequency of 300Hz, less piercing than the standard 1kHz and since I suggest you use a Digital Multi-Meter to measured the levels that is low enough to be in its accurate range. Much over 1kHz will not be.

Once you have the voltage differences there are several online calculators that can turn them into "dBV" or "dBu".

If you don't know how to test this, come back to me and I can walk you through it. I will however need an attached user manual/better service manual. These will also surely give you the specification including channel match?

Jusfort! The desk might have a built in line up sine generator of its own!
Dave.

[Wonks]

Earth to Dave, Earth calling Dave.

This isn’t about aligning the VU meters. The OP has taken the mixer outputs into his DAW to compare the signal levels on the L and R outputs and noticed a very slight discrepancy in levels.

0.2dB RMS level and 0.4dB peak. That’s probably under the threshold for the human ear to tell a difference, and you’ll get far bigger differences between drivers in speaker and headphone response, so it’s not a value to be concerned about.

A sine wave is an easier wave to measure accurately, so the OP may want to try again with a sine generated by the DAW and fed from the audio interface back into the mixer. They can then try the sine at different frequencies to check that the frequency response is the same on both channels.

[ef37a]

Saturn (see Holst) to Wonks. Gotcha. You did not however spot that I mentioned a contributor that is not actually part of this forum!

Sweetbeats is the expert on all things whirly and analogue over at HR.com

Bleary and not had me Alpen yet. MUST put lappy away.

Dave.

[Hugh Robjohns]

This highlights the dangers of looking at the numbers and ignoring your ears!

0.2dB difference between channels is perfectly fine for a vintage analogue mixer and not something I'd get even slightly bothered about.

[ef37a]

This highlights the dangers of looking at the numbers and ignoring your ears!

0.2dB difference between channels is perfectly fine for a vintage analogue mixer and not something I'd get even slightly bothered about.

True Hugh true but that is what the OP asked. Also I hope it never happens to you but I can no longer trust my ears. Not only are they very mutton but I also have a left/right discrepancy.

Dave.

[Hugh Robjohns]

It would be rather silly to invest in a Studer 928 if you couldn't trust your ears...

But I should have been clearer. A level discrepancy of 0.2dB is definitely inaudible and virtually unnoticeable on analogue meters -- even the lovely twin-PPM.

But on a DAW with digital readouts, different numbers take on a much greater apparent significance than they deserve.

Hence it being better to use metering to confirm and quantify what your ears are telling you, not the other way around.

[ef37a]

"It would be rather silly to invest in a Studer 928 if you couldn't trust your ears..."

?? Never said I woz Doc?

Dave.

[Primary perception]

Thanks a lot everyone for all the info!

It has been really helpful

I thought that was nothing important because to my ears was good but I wanted to be sure about it. ( Always the fear that something is broken)

[ef37a]

Thanks a lot everyone for all the info!

It has been really helpful

I thought that was nothing important because to my ears was good but I wanted to be sure about it. ( Always the fear that something is broken)

"Something" will always break eventually! Especially with old analogue gear, that is why the 'professionals' tend to have their systems backed up as much as possible.

Can I suggest you introduce yourself over at HomeRecording.com An American site but they are quite civilized (mostly!) Sweetbeats is a proper gent and his life is spent sourcing old tape recorders and allied gear and restoring it to full factory specification.

I am sure there is a similar expert here in EU but I know not of them.

Dave.

[James Perrett]

Can I suggest you introduce yourself over at HomeRecording.com An American site but they are quite civilized (mostly!) Sweetbeats is a proper gent and his life is spent sourcing old tape recorders and allied gear and restoring it to full factory specification.

Having dipped my toe in the water over there over the years, I think you'll find that there is far more real expertise lurking here.

[Primary perception]

One question guys if you dont mind.

Anyone of you knows whats is the audible difference on both side for the human ears in dbs?

Just to know how much is it.

[ef37a]

Can I suggest you introduce yourself over at HomeRecording.com An American site but they are quite civilized (mostly!) Sweetbeats is a proper gent and his life is spent sourcing old tape recorders and allied gear and restoring it to full factory specification.

Having dipped my toe in the water over there over the years, I think you'll find that there is far more real expertise lurking here.

I can quite believe it James but where and who are they?

Dave.

[Primary perception]

Thanks a lot everyone for all the info!

It has been really helpful

I thought that was nothing important because to my ears was good but I wanted to be sure about it. ( Always the fear that something is broken)

"Something" will always break eventually! Especially with old analogue gear, that is why the 'professionals' tend to have their systems backed up as much as possible.

Can I suggest you introduce yourself over at HomeRecording.com An American site but they are quite civilized (mostly!) Sweetbeats is a proper gent and his life is spent sourcing old tape recorders and allied gear and restoring it to full factory specification.

I am sure there is a similar expert here in EU but I know not of them.

Dave.

Thanks Dave!

I will open a threat there.

[Wonks]

One question guys if you dont mind.

Anyone of you knows whats is the audible difference on both side for the human ears in dbs?

Just to know how much is it.

There is no single figure. It depends on both frequency and volume. You’ll often see a 3dB difference being quoted as the minimum level difference detectable by the ear, but that is very much a generality. I’m not able to look it up at the moment but at certain frequencies at certain dB SPL sound levels, it can come down to about a 0.5dB difference.

That is probably a conscious noticeable dB difference. The subconscious/brain is probably better than that when using sound levels and phase difference to determine where a sound is coming from.

The age of the listener will probably have a big part in the detectable volume difference value (the younger the better), plus ear training will come into it. If you are used to sitting listening to mixes, trying to hear any out-of-tune notes and balancing levels by very small amounts, you’ll probably be able to detect smaller differences in level than someone who doesn’t work with audio.

[Primary perception]

One question guys if you dont mind.

Anyone of you knows whats is the audible difference on both side for the human ears in dbs?

Just to know how much is it.

There is no single figure. It depends on both frequency and volume. You’ll often see a 3dB difference being quoted as the minimum level difference detectable by the ear, but that is very much a generality. I’m not able to look it up at the moment but at certain frequencies at certain dB SPL sound levels, it can come down to about a 0.5dB difference.

That is probably a conscious noticeable dB difference. The subconscious/brain is probably better than that when using sound levels and phase difference to determine where a sound is coming from.

The age of the listener will probably have a big part in the detectable volume difference value (the younger the better), plus ear training will come into it. If you are used to sitting listening to mixes, trying to hear any out-of-tune notes and balancing levels by very small amounts, you’ll probably be able to detect smaller differences in level than someone who doesn’t work with audio.

Thanks a lot for all the explanation!
I have now an idea about it

[RichardT]

Yes, that sounds about right. There is a difference, though, between how sensitive we are to absolute volume levels (for example, increasing the value of a whole musical piece by x dB) and relative volume changes (for example, changing the volume of one channel by y dB while leaving the other channels alone). In the latter case, we are more sensitive to changes as they affect the balance of the music, and 0.2 dB of change can sometimes be audible in that context, in my experience and that of other mixing engineers.

There’s a story of Donald Fagen taking some time to consider whether to apply a 0.1 dB EQ change during mastering and deciding in the end it had too many negative side effects.