This is going to be tough to describe in writing, but I'll do my best. My questions concern the proper slope or curvature of the bridge top, to give the right amount of bowing space for each string. It's hard for me to bow the D string cleanly, because its "height" in the bowing area is very close to the height of the G and A strings on either side of it. Particularly when I'm up in thumb position on the D string, it's nearly impossible to get a clean bow stroke without also hitting the G or A strings. This doesn't occur with any of the other strings. I did some measuring to try to quantify this. Again, this may defy written description but I'll try. With my bass standing up in a stand, I laid a ruler flat on the bridge, up against the undersides of the strings. I drew a straight line from the underside of the A the string to the underside of the G string. Then I found that the underside of the D string is about 3 mm above that A-G line. Then I drew a similar straight line from the underside of the E string to the underside of D string, and found that the A string is about 5 mm above that line. So, in other words, the A is more "separated" in height from its neighbor strings, while the D has less separation in height from its neighbor strings (again I'm talking "height" at the bridge and in the bowing area, not on the fingerboard). It may not seem like much of a difference in mm, but it really seems to make the D much harder for me to get a clean bow-stroke. Would it be worthwhile to get a new bridge, or get my bridge re-cut somehow? Or do people think this wouldn't make much of a difference? I'd appreciate any thoughts on this.