The other pot is for the midpanels, no wonder it sounds lean! Turn em down to about 12:30 and tweak from there in 1-click increments. When you turn them to the proper range you might need to turn up the tweeters slightly. I won't bring up the putty.
Fred has offered the best advice and the first thing to try.
Depending on how old the speakers are they could have differing handoff from the woofers to the Midrange Panels.
His may be 166Hz (newer models are 220 - 280)
Your friend should also read the "set up" stickie here on the VMPS CIRCLE.
The L-pads (pots) adjust the volume of the tweeter and Midrange panels in relation to each other and in relation to the woofer.
Turning them down, is the same as boosting the woofers and vice versa.
Chances are the previous owner only "pinched" putty. If it were me, I'd start by adding a good amount, like say the size of a marble (make sure and listen to a familiar bass heavy reference cut.
Heavier mass will slow the PR, and cause it to reactively produce the lower bass frequencies. Lower bass will add a "richness" to the whole sound and might also be just what you need.
You are listening for "bass tone, richness, detail, and balance". If you hear wooliness, fuzziness, or one note bass you need to then start pinching part of that marble you added.
DO NOT USE MULTIPLE CUTS trying to get the same detail on each. It has to be done on a single cut. Due to recording differences, trying to get a bad recording to match a good recording is not possible.
My favorite reference cut is by
Bela Fleck and the Flectones, and is off their double CD LIVE album and is called
Amazing Grace.
It has
bassist Victor Wooten playing LIVE, and his playing is all over from midrange to deep bass. You should hear incredible detail in the midrange and upper bass in this cut, and that will likely give you the balance you want.
As a second option; If your room is such that it "plays" with the frequencies at the listening position, you might also try "raising" the speaker 6" - 8" off the ground. This reduces slightly the room gain from the floor coupling of the woofer/PR, and places the Neopanels more at ear level.
My guess is you have "spiral ribbon" tweeters, so your ear should be at the top of the highest NeoPanel, just below the tweeter.
A similar effect, but not as good is to tilt the RM2 back slightly, so that it fires more directly to the listening position.
Take your time and don't do everything at once, so you can hear the differences the adjustments make.