Fletcher Munson 'Loudness Control' Video

I don’t miss tone controls much, but I think the loudness button might be fun to have back.

Ideally it wouldn’t be a button. It should be a potentiometer so you can adjust the amount of compensation according to the volume control setting. But maybe you were speaking euphemistically.

Hello Lewm,  For $100 you can do that on a Schitt EQ. Just adjust the 1st and last controls up slightly or a bit more. Or, per Gdaddy1, adjust the middle controls down slightly or a bit more. 80% of the time I have it out of circuit. 20% of the time the improvement is much better than the slight degradation. It makes some rock and classical listenable.  -JAS in Phila. 

Ideally, you want it to be automatically and progressively implemented as you lower the volume below your ’normal’.

That is how the Yamaha and some others work.

Even better: remote volume control.

The Chase RLC-1 works like that, however it only progressively boosts the bass, no treble involvement. Raise the volume, the boost is progressively reduced, raise it above normal, no boost at all.

We old dogs are not hearing ’real’ highs at normal volumes, as they say, most people adjust the bass.

How can a receiver, particularly a vintage one, sense the SPLs in your room across the audio spectrum and then compare the responses at key frequencies, in order to introduce the proper loudness compensation? Answers: it can’t. You have to do it by ear which is why ideally you want a potentiometer in order to adjust by ear or by in room measurement.