Mysterious 3dB difference in signal levels

I’m seeing a -3.0dB level difference that I cannot figure out where it is coming from.

I have a mono input (mic) that is the source for 2 Audio Tracks - one mono and one stereo. All 3 have their faders set to 0, panned center. When I test the mic the level is in the -20dB range. If I reset the meters and then test the mic, the Input and Stereo Audio Track always show exactly the same peak level while on the Mono Track the level is always -3.0dB lower. Exactly 3.0dB - never 2.8 or 3.1, always 3.0.

I’m trying to understand where that level difference is being introduce. Initially I thought maybe the Pre had some gain reduction - but no. I’ve bypassed the Pre, Inserts, EQ, Strip and Sends sections on both Audio Tracks - so there is basically no processing going on between the Input and each Track’s fader. Still the 3.0db difference remains.

I have my Pan Law set to Equal Power. But it doesn’t seem like the stereo/mono difference should be causing this. If it were related to stereo vs. mono I’d expect the mono Input and mono Audio Track to match with the Stereo being different - but it is the other way with the Input matching the stereo Track.

I figure there must be someplace else along the signal path where the gain can be adjusted, but no idea where that might be.

I dont get it? You sum two mono channels to center on a stereo track and compare that to the mono? I probably don’t get it, what did you expect it to be? The stereo signal is a sum of two identical copies.

Your meters are probably set to “post panner”?! Then the meter reading is indeed due to Pan law.

Hmm that’s interesting mystery. I think you could restate this without mentioning the stereo track, right? In other words, just say: the mono track is 3db lower than the input. I would wonder about two things: does a pre fader meter plugin show the same thing? And is the audio file 3 dB lower than you expect?


Most probably!

This seems to be the culprit. Changing it to “post fader” showed the levels being the same. I’d never changed this so I assume “post panner” is the default.

However I’m not really clear about what is occurring. Why would the meter position change the level on the Mono Track but NOT have any effect on the Stereo Track? Also while in “post panner” meter position if I bypass the panners on both Audio Tracks the level discrepancy still exists.

Exactly, the Stereo Track can really be ignored. The level difference is between mono input and mono Track. I put meters on inserts both pre & post fader and they both matched the input’s level - but that would still be pre-panner, so… I guess this implies the recorded audio will be recorded correctly and the level issue is only related to playback.

Curious to how other folks have their meter position and pan laws set and why. I’ve always left them on their defaults (well, I think that’s true).

Equal Power, simply because it sounds the best to me.

Because pan law is disabled for stereo files on a stereo track.

Pan doesn’t sound anything - it is purely volume level.

Because pan law applies to mono tracks routed to a stereo source. And bypassing the panner means the same as setting it to center.

If you raise the volume it will *SOUND louder and i might even change how your mix *SOUNDS.