question about back graduations

[Ken McKay]

Well, since the meastro spoke, I might take a turn.

Regarding the players responses to the listening test being contradictory and variable. Browns summary on the subject:

• It can be seen that the opinions of bassists on the subject a spectrum of bassists contains bassists that believe the difference is clear and important and others who believe there is no significant difference. Many of the responding bassists are somewhere in between, unsure if a real difference in sound between the two types exists.

And then Brown goes on to show that there is an acoustic difference and measures it and publishes it. Interesting that players have variable views but it makes perfect sense since both types are seen in modern orchestras almost interchangably.

Martin Schleske a modern violinmaker who is alive today makes "tonal copies" of some of the finest stradivari and del Gesu violins. He charges a small percentage of what it would cost for an original. As a physicist and violinmaker he has developed some techniques to test and replicate violins. Schleske was quoted by Brown in the dissertation on page 47 to say:

• "To make an acoustal copy of a Guadagnini bass, it would cost almost as much as the original instrument. The ratio between the cost of an original violin (DM 1,000,000) and an acoustal copy (DM 40,000) is much more attractive than as with a bass (DM 150,000 and DM 75,000)"

And an interesting comment on page 48 (with and illustration by J Bollbach) regarding the static pressures on the bass.

• "The back plate of the double bass is subjected to strong forces. The back serves as the anchor for upper and lower blocks, as a platform for the ribs, and supports downward string pressure on the top plate through the soundpost. Each of these areas must be strong enough to support the static forces as well as dynamic forces during playing and transport. About 2/3rds of the downwardstring pressure is supported by the soundpost, whichmay be calculated to about 353 N. (79 lbs) According to Guth."

Seems like a perfectly good place to put a spring if you are looking to recoup some free green energy. And here is also where the graduated plate, thick in the center and thin at the recurve, works to a similar advantage. Or a sprung X brace.