RD/Man made this comment on the HC forum MTS thread awhile back:
"I wanted everyone to know of a recent modification that we're making to the RM100 Density control. Currently this pot is a linear taper meaning that is comes on very fast so at about a 10 or 11 o'clock setting you are increasing the bass a ton. We just started changing the Density control pot this month to an audio taper pot which increases the bass much more evenly when you turn the pot up.
For all of you currently using the RM100 and finding it has to much low end for you, I would suggest you try turning the Density control all the way down to start, then bring it up slowly until you find the right spot. You may only need to turn the Density knob up to 9 or 10 o'clock, but this is fine because again the pot is coming on and boosting the low end very fast.
Thought this might help everyone to control the lows better."
I'm not sure if I have the old or new pot in my RM50B, but I'm currently running density at 11:00 and presence at 10:30.