D200 not very good sounding at low volume

[Dr Tone]

And there is a loudness feature which you can set up in the configurator, and assign a button to. The contour boosts some frequencies, compensating in part for the way ears hear at different sound pressure levels.

Are you talking ICM?  Not really the same thing as a stereotypical loudness button.

After someone else asked me about the loudness function, I went back to the configurator to try and find it. I could not. I do believe I remember having such a function assigned to a button on the remote, but it seems I was mistaken. I have not actually been into the configurator in many months, probably six or eight, so I've clearly made up the loudness function on my own. My mistake; apologies to all.

It would be a nice option.  Even the ability to toggle the tone controls on and off would be cool.