AVID related question

Hi Guys, an editor friend of mine asked me a question and I promised to look into it, maybe some of you can help?

In AVID he uses 4 Mono-Channels of Audio. Ch 1 is Dialogue, Ch 2 is Atmo, Ch 3+4 are Music Left and Right.
All Channels are routed to two Mono Output Cannels 1+2 which add up to a stereo Output Channel panned left and right on an outboard mixer.

Ch1+3 (Dialogue+Music Left) are routed to Output Channel 1 (Left) and Channels 2+4 (Atmo+Music Right) are routed to Output Channel 2 (Right).

In this configuration he listens to the music in stereo but the Dialogue is hard left and the Atmo is hard right. When he pans the dialogue to the mid inside of AVID he loses 3db of Level. How can that be?

Obviously Audio Routing in AVID works a little different from Nuendo so I have no clue how to solve this problem for him. He needs to listen to the dialogue and the atmo from the mid and the music in stereo so he can do a mix of all channels that also works when he gives all four mono stems to the voice overdub studio, they work on pro tools.

Tell him to search the avid manual for stereo pan law

If you sum two mono signals (equal volume L and R), you get roughly 3db of percieved gain. Stereo pan law preference tells the mixer to lower the level of a center panned signal by 3db to compensate. I don’t know if this is adjustable in Avid, but theoretically, he should be able to work with the dialog and atmo centered and get accurate results.

Thanks for your reply! But the problem is that it’s the other way round, when he centers the Dialogue he “loses” 3db of Level - which I find rather strange.

But the problem is that it’s the other way round, when he centers the Dialogue he “loses” 3db of Level - which I find rather strange.

No, that is correct!
You have a test signal of -12dBfs panned to the very left. The level meter displays -12dBfs (just on the left).
When you now pan this signal into mid center position, the signal will be played by two speakers.
As Kid Dropper mentioned, when giving a mono signal to two speakers the signal is percieved with a higher gain of +3dB.
To compensate this perception, this signal is levelled down by the software: The meters will display -15dBfs (left and right).
But the perception of the signal will be with constant loudness of -12dB. So you’re not “loosing” level, you just beware getting more level…

To explain this correctly, the OP should be specific about the measurements.

x-dB higher/lower … on which meters?
The PT meters? The meters on the mixing board? Auditive?
And how are is the computer connected to the mixing board.
Channel by channel, or the outputs to two mono channels/ or 1 stereo channel, etc …

But the explenation about the Pan Law is correct, and it is what is happening.
The only unknow is to where in teh chain this happens.


To explain this correctly

Of course I’m aware of all the other detailed metering issues, but I just wanted to explain this as simple as possible. The question itself (which probably wouldn’t have come from a long-experienced sound engineer, I hope you don’t mind) let me guess that a simple explanation would be more helpful than a long dissertation about metering…


I am afraid you misunderstood me.
What I am saying is that what you said is indeed correct.
However, the OP hasn’t provided the neccesairy information to find out where the problem occurs.
The pan law setting can be set wrong in PT, or the routing to his console might cause problems, etc …
So it is important where (PT, console, listening) you test this.


Hey Fredo, I actually don’t know the setup because it’s not mine. There is a hardware meter in the audio chain but i don’t know if it’s before the hardware mixer for sure - but i guess so. On this meter you see the audio lever decrease by appr. 3db when panning the (mono) dialogue track from the left to the mid. And no I am by no means a sound engineer, I’m a composer :wink: