I found this old post from 2014 from Oliver, where he described how to carve a violin bridge to alter the tone.
I do not intend to overwhelm you with references but some of these are really great.
This is about giving a violin more of a bass "presence" . I think I have to try some of this
Back to the bridge:
Try filing the following parts iteratively but roughly in this order:
1) File the arc between the bridge feet but file more under the A/E strings. (Listen)
2) Increase the size of the (big) hole in the ear under the E string. The channel between the heart A side and the E side is thinned but file the hole to keep the hole pleasant to look at. Most important again:listen to changes in tone color.
3) If needed file the heart under the A string to balance (increase) the D string volume compared to the other strings. File the heart under the D string to adjust the A string volume. Warning: If you make the heart to big the sound becomes "nasal" and unpleasant.
4) If the bass side gets too nice and round and uninteresting then file the G side ear side and opening which adds "some sting" to the bass. If you over do it the bass gets dry.
Go back to step 1 and start a new round.
It is usually a good idea to do one round and then play the instrument for one or two weeks before the next round to allow the bridge response to be stable. You can hear that the filed bridge to some extent goes back to the state before filing (which is fortunate!).
The key is to do only small steps and to learn to listen. As a general rule you get more volume by filing the openings in the arc, the ears and the heart. Overdoing it gives you an unpleasant nasal sound so you have to experiment and you have to learn to listen."
Can anyone offer me more information about this? I've been experimenting, and may have ruined a bridge by carving too much. I'm trying to get more projection on a particular violin - specifically out of the E - and haven't had much luck. I've gotten more projection on the G, D, and A, but the E is still pretty weak.