What's the reason why a 1M volume pot sound "brighter" and a 250K pot sound "darker"?

[vat]

Hi All,
i read that a 1M volume pot sounded brighter and a 250K pot sounded darker.

Does it mean that the 250K pot rolls off quicker while the 1M pot rolls off higher up the frequency spectrum?

If that's the case, is it better for me to use 1M pot so more of the higher frequencies could pass through and i could trim them off using the preamp section of gain stage?/ or even at power output stage?

(The combo amp i used has a preamp stage for gain, bass & treble controls. Then there's also another set of bass, treble, mid & master vol controls.)

Thanks

[Stealth]

It's been explained visually and verbally in this thread:
Passive basses and the volume control, an explanation (science warning)

Wonder why it hasn't been made into a sticky.

[vat]

Thank you very much. It's very technical so i'm taking a lot of time to digest. Interesting read.