I was recently talking with one of our students about my mandolin bridge experiments, and thought that others might like to see some examples of how I found out which bridge woods sounded the best. Here's a detailed experiment in which I compared mandolin bridges made from ten different woods other than maple, and some of the woods were rather exotic (each bridge is about 4 inches long):
Here are the 10 woods, with the weights when the bridges were finished and tried:
In the left column:
Bridge #83. Ebony, 10.5 grams
Bridge #85. East Indian rosewood, 7.5 g.
Bridge #84. Brazilian rosewood, 8.9 g.
Bridge #67. Bloodwood, 10.4 g.
Bridge #66. African Blackwood, 8.7 g.
In the right column:
Bridge #89. Extra-heavy maple, 7.1 g.
Bridge #90. Teak, 7.6 g.
Bridge #88. Satinwood, 10.1 g.
Bridge #91. Persimmon (American Ebony), 8.7 g.
Bridge #92. Honduras mahogany, 6.4 g.
...and here were the results:
83. Ebony: Good volume and sustain, but not exceptional. Bass quite solid, but not as deep as with the best maple bridges. Overall tone very clear, but somewhat restrained. Good "chunk" in the lower positions, but the chunk gets a little harsher up the neck. Treble volume and richness somewhat muted.
84. Brazilian rosewood: Good volume but a slightly tubby sound. Low end good, but high end is rather thin. Up-the-neck chunk has good volume but is a bit sharp-sounding.
85. East Indian rosewood: Fair volume. Pretty good bass, but midrange and highs pretty weak. Definition not good even on bass notes. Up-the-neck chunk harsh. Sound flabby overall. (Cut about 45 degrees to the quarter.)
67. Bloodwood: Good volume. Bass solid, but lacks a little in richness. Midrange good, but highs a bit thin.
66. African Blackwood: Fairly good volume, but low end a little dull. More body in the high end. Better up the neck than either of the rosewood bridges.
89. Extra-heavy maple: An extremely satisfying bridge. Rich highs and lows, plenty of volume, evenness, and sustain. A great sense of "immediate response" from the mandolin. There seems to be only a small difference in response between this bridge and my very best maple bridges, but perhaps it is due to the fact that due to the grain in the block, I had to cut this bridge about 40 degrees from the quarter.
90. Teak: This wood was quite heavy and had the general appearance of mahogany, except that it was darker. The bridge gave plenty of bass but without as much definition and richness on the low notes as with the maple bridges. The mids and highs were fairly well balanced but a little weaker than with maple. Still, this was a pretty satisfying bridge.
88. Satinwood: A really good bridge! Rich bass, good low-end chunk, and smooth highs with plenty of body up the neck. This is all a nice surprise, especially since the bridge had to be almost slab-cut from the small block I have. More experiments with satinwood are indicated, especially if I can get some of it thick enough to cut a quarter-sawn bridge.
91. Persimmon (American Ebony): Not as much "body" to the sound as maple or silkwood, and highs a bit thin. Still, better than average in this group.
92. Honduras mahogany: A surprisingly good bridge! This bridge and #88 (silkwood) were the only two in this test which were really comparable with maple. This mahogany bridge had resonant lows, well-defined highs, and good sustain. I plan to do some follow-up work using this wood.
. . . . .
--as you can see, most of the woods sounded okay but only a few really sounded good. This was what I had to find out. None of these bridge woods sounded better than maple, and only a few came close. I've probably tried about 30 different woods now, and haven't found any wood as good-sounding as maple for mandolin bridges!