Stereo Pan - Reduces Track Volume?

Audacity 2.1.2, Windows 7
Six piece jazz group studio recording session, originally recorded with Pro Tools

With other software, if I pan a stereo track all the way to the left, well, the way this works is usually to turn the right channel all the way down. I think the result then is to reduce the overall volume of the music.

With Audacity I’m working with mixing something like 9 tracks, all mono. If I pan a mono track to the left does this reduce the overall volume of the track? What is Audacity doing with ‘Pan’? Does Pan just move where the track is in an eventual stereo mix? Or does panning a mono track in Audacity also reduce the overall volume of the music on that track? Would that track be LOUDER if it was left in the middle?

If I do lose some volume by panning tracks it would seem that I should set all the Pan locations first, then proceed to adjust levels for the mix.

Thanks for any info,
pete in oakland, california

I can’t answer your question but yes, it’s best to set your pan locations first, although it can be an interactive process. Some people recommend mixing in mono, but if you want to do that I’d still recommend panning first, then set-up your system to for monitoring.

There is something called a [u]Pan Law[/u], but I don’t know what pan law Pro Tools or Audacity uses… Some DAWs will allow you to choose the pan law.

As long as you are not moving sounds across the soundstage during the performance, it’s not that critical because you can adjust each track individually for the best overall mix/sound. If you are “actively” moving sounds around, you’ll want a -3dB “constant power” pan law.

Note - If you are using compression, that will tend to push everything that’s not hard-panned toward the center as the compression tends to even-out the levels. Be especially aware of this if you are doing an additional mastering step, because the compression during mastering can narrow your stereo image compared to what you heard during mixing.

[u]Moulton Labs[/u] has an interesting article about panning… I learned that there’s no point in trying to perfectly-position everything across the soundstage.

Funnily enough this came up on the developer’s mailing list just the other day.

How panning works in Audacity:
Panning, whether mono or stereo is on a scale of +/- 1.0 where 0.0 is centre panned,

  1. Stereo tracks:
    Pan at zero plays both left and right channels without modification (“unity gain”)
    Panning to the right (positive value of pan) keeps the right channel unmodified, and reduces the left channel proportionally to the amount of pan. When panned all the way to the right, the left channel is silent.
    Panning to the left (negative value of pan) keeps the left channel unmodified and reduces the right channel proportionally to the amount of pan. When panned all the way to the left, the right channel is silent.

  2. Mono tracks:
    Basically the same as for stereo track, though it’s (obviously) the one mono track that plays through left and right. The level in left and right channels follows the same rules as described above.

Thanks much to DVDdoug and Steve for some input.

I think maybe both may agree that there may be some drop in volume when panning. I’m not sure I have got an answer to how MUCH of a drop in db there is with, say, a 20% pan to the left or right. I can try and just make a test with a single track and measure the results.

I was just hoping SOMEBODY may have done this already. I have some vague memory of 1 divided by the square root of 2 (=.707) might be what theory says with extreme pan to left or right. Don’t know why that number is stuck in my craw but perhaps that’s close to the -3db in the Pan Law sited by DVDdoug. From what Steve says, perhaps this is correct?

So less panning would be proportionally less.

Bottom line: I’d better Pan first before adjusting the mix!

Related to this, suppose I duplicate my sax track, apply reverb to that and then mix the two. First, does reverb increase volume? How much increase is there from mixing the two tracks in equal proportion?

pete in oakland, ca.

What exactly do you mean by “volume”? Are you talking about peak level, RMS level, subjective loudness, or something else?

The Audacity Reverb effect will generally increase the peak level, if “Wet only” is not selected. Exactly how much increase depends on the settings and the audio that the effect is applied to. For example, applying reverb to silence makes no change to the amplitude - it remains silent.

Thanks so much, Steve, for this.That’s an interesting question. Maybe all of the above?

Please follow me on this, I know I’m repeating myself here, but I’m new to Audacity and to mixing tracks:

In Audacity each track has a “volume control”, what I guess could be called the track’s “Fader”, a slider control that has “+/-” That’s what I use to adjust track levels. If I raise a track’s volume with that Fader I would say ALL of the above rise: peak level, RMS and “what my ear tells me.”

Anyway, this control is measured in decibels though I also think in terms of percent, e.g. “20% louder.”

Whether it’s db or percent, I’m wondering if there is a number or formula for how much louder an instrumental source is if I duplicate that track and mix it in (equally)? This would come in to play if I duplicate my sax track and apply reverb. I’ll leave out the issue of reverb. I’d have two copies of the same track where before there had been one. Isn’t there a formula for how much louder that instrument now sounds? I’m pretty sure it’s not double (2x, 200%). If I wanted to preserve the mix level of this instrument relative to the rest of the band wouldn’t I want to reduce the Fader on each copy of that track? How much in decibels? I can do this by ear but it would be nice to have a starting number to use.

This is sort of like the issue of Panning. If I’m playing a mono source on my stereo (through both speakers), how much of a drop in “loudness” is there if turn the balance control all the way to the left, meaning turning down the right channel all the way?


If the duplicate is exact, so that there is no destructive interference, the peak value and the average RMS value of the mix double in volume, which means they go up by 6 dB.


Thank you, Gale. Very helpful. I’ll test this out.

Can you apply this to Panning? If a track is panned all the way left in Audacity does this reduce the volume (RMS and peak) of that track by half or ~6db? What about a 50% pan to the left?


See here: