PAFL question

[BracumbaParticipant]

I setup the SigGen with a 1.00kHz Sine. Input 1 , in source select I chose Signal Generator.
Brought fader input 1 to exactly 0, and LR to +4dB, exactly the end of the ‘dotted’area on the SQ mixer surface.
Input 1 is assigned to LR. Nothing els is happening in the mixer.
Now when I PAFL input 1 I read a True Peak of -18.0 dbTP, and when I PAFL LR it reads also exactly -18.0 dBTP.

When the LR fader is positioned at exactly 0 and PAFL LR, I get a reading of -22.0 dBTP. The reading is 4dB lower, as can be expected by lowering the fader from a +4 position (the end of the ‘dotted’ area) to 0 (the ‘middle’ of the dotted area), and PAFL here is ‘after fader’

Am I doing something wrong, or understanding something not fully ? I would have expected the same reading with both faders (The input 1 fader and the LR fader) at the zero position. And there must be a good reason why A&H ‘dotted’ a 4 dB area around 0 on the control surface of the SQ. But what is it ?

Can anyone enlighten me on this subject please ?
Thank you so much (just want to learn 🤓)

[KeithJ A&HModerator]

Hi Johan!

Sorry to disappoint but the dotted area around the 0dB point does not have any particular meaning other than to say “hey look, here’s 0dB!”, so there is a good reason but it’s a ‘visual aid’ rather that representing anything internal.

The 4dB difference will be due to the pan law used (https://en.wikipedia.org/wiki/Pan_law), you can try routing the same signal at the same level to a mono mix and should see there is no change 🙂

Hope this helps!
Keith.

[BracumbaParticipant]

And, as always, this helps. Thanks, once again. I wrongly assumed the pan law always used 3dB compensation.Thanks for the Wikipedia Link to correct that.
Is it correct to conclude that the SQ uses 4dB to compensate in the pan law, and that the dotted area not only says “hey look, here’s 0dB!”, but is also a little indicator of this fact ?
By the way, even after more then three years the A&H SQ, never dissapoints 😊.

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