Hi baires0314,
I haven't checked the sound yet, but based on your description Multiband is NOT the way to solve this. Basically you want to change the behavior of mids vs. highs vs. lows. That is currently not really possible

because the relation is now hard coded (bass protection against loud highs etc., if you are folling the BETA development you know what I'm talking about).
The only thing you can do - and this does not work if you use FM output - is to use singleband compression or the singleband AGC in the Loudness window. That will reduce the entire volume when loud sounds - and normally that means loud lows - kick in. (The problem with FM output is that if that's enabled the volume gets lowered too much by highs, because they are very loud).
EDIT: I'm listening now, I think the trick is something different: Use VERY LITTLE multiband. Actually very little of everything. It's not so much that the bass drops the other sounds down, but that very little compression is taking place - the sound is close to the original. (And does indeed sound really good).
So:
- Keep Loudness below 2.00 (and probably lower)
- Make VERY limited use of Multiband. Make sure that the volume is almost not dropped, and set the 'up speed''s low.
- Keep Pre Amp low. (~ 2.00)
- I *think* you also need Bass Boost, but I'm not sure because so far I haven't heard any tracks that I know (they could be recorded this way).
To make 'S' sounds smoother, you can either use Clipping in Multiband (set the Clipping values for the high frequencies lower), or use the de-esser in Loudness (for that you'll have to turn Loudness on).