Bridge Height Matters?

September 9, 2016 at 03:22 AM · The only things that affect string tension are the vibrating length of the string, the string brand, and the tuning basis (i.e., A=440Hz or whatever).

What the height of the bridge affects is the force on the instrument top from those strings.

Some instruments do better with greater force on the bridge, some don't. It is one reason why different strings do better on different instruments. The critical measurements for height height and curvature are the height of the different strings above the fingerboard along its length. But you can't count on the maker to have angled the fingerboard optimally for the particular instrument under it - but you can hope! I've seen a 15 mm difference in the height of cello bridges (one student bought an ebay cello that required a 100 mm bridge blank to fit the fingerboard angle - that is a lot!).

September 9, 2016 at 12:40 PM · The bridge and nut height, as well as the scoop contribute to the distance of the strings from the fingerboard, which affects the amount of force needed to press the strings, or apparent tension to the player. Differences in string heights of 1/2 to 1 mm at the end of the fingerboard may be felt by the player. Search for discussion on string heights for more information.

September 9, 2016 at 12:55 PM · Bridge height can also affect string response and quality of sound. See this vintage thread, recently reactivated:

Trouble with high notes on G String

Read OP’s initial post; then scroll down to his follow-up comment on 10-3-2008 that “the G string was 7 mm above the fingerboard at the point closest to the bridge. The correct distance is 6 mm. They [the professionals at the violin shop] adjusted the bridge and it really helped.”

September 9, 2016 at 07:30 PM · I have a sort of "jack": a plastic bridge with a screw to change its height.

It is used behind the real bridge to raise the strings enough to remove the bridge (for modification or replacement) without touching the tuning pegs. I found that raising the jack by 1 or 2 mm, the strings sounded about a semitone higher. I was surprised that the effective vibrating string length was that much increased, enough to cause a 9% increase in string tension.

September 9, 2016 at 11:19 PM · Adrian, that's because you stretched the string when you raised it, but if you then tune it, as you would if that were your normal bridge, then it would be a semitone lower - but because of the more acute angle of the string bend, the downward force on the bridge will be increased. Also, most of these bridge jacks are rather flat across the top, changing things some more (I've got one I use for vln & vla and another one for cello). Very handy things to have.

September 9, 2016 at 11:38 PM · Yep.