Hi Riis, ditto what slinkp said, I don't use the RNC for bass anmore.
And for that exact reason, because it has way too much low frequency distortion, and the only way to get rid of it is to set it up for unacceptably fast dynamics. In other words, I've had the exact same experience with mine, as you're having with yours.
IMO the RNC is a great little compressor for vocals and high frequency stuff, but it pretty much sucks the big weenie for bass players, especially people who play 5- and 6-strings (or let's say, "extended range instruments").
For bass players, the DBX-type compressors are pretty much the industry standard, they have nice dynamics for bass work and they're okay for live too (as long as you don't squish too much). In the studio I prefer the old Urei's (like the LA-4 in particular has a wonderful bass sound).
I have a little EBS stompbox ("MultiComp") that's not bad, it has three different "styles" of compression that are switch-selectable, and they all sound pretty good. They're more or less in the same ballpark as the RNC's price-wise, maybe a little more, but they're probably worth the extra few bucks if you depend on your compressor for live gigging. If you're only using your compressor in the studio, then I'd say nix that whole idea, and just rent yourself an LA-4 on an as-needed basis (you can get them through the rental places for maybe ten bucks a day, or twenty five bucks a week).
