@Noel;

Thank you smile

Great detail smile

Blending the 6dB and 3dB slope from your measurements would explain the 4.5dB slope I am seeing in the plugins I use. I guess it may have been chosen as a rough average between the two. It certainly fits the math of it.

I am still not sure which brightness people would prefer though, if a single linear slope is to be used.

I suppose the ideal would be if the spectrum-display could weigh the signal according to the equal-loudness curve, such that a signal that fits that curve would appear as flat across the spectrum-display.

But of course that would only work for one single sound-level, and since people listen to music sometimes loud sometimes quiet we need to find some middle-ground that covers both situations. A slope that sounds good (not too dark, not too bright) both when played loud and not so loud.

According to the equal-loudness curves, music played at lower volumes should have a darker curve than music played at louder volumes. That might indeed explain why modern pop is using +3dB while jazz is using +6dB (people who listen to pop (kids and young people, crude generalization) play louder than people who listen to jazz (people with a bit more 'life experience' wink Again; crude generalization))

Thanks again Noel. Reading your post gave me some more perspective on this smile
It would appear there is no 'single-slope-fits-all' solution out there smile

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