Wednesday, February 26, 2014

String angles, Please tell me if I'm wrong

I forgot to put this in, so I'm scrambling.

String angles are like a holy grail to some. I've read people who swear by 159 degrees for violins; certainly not less than 158 degrees. But in drawing out violins with higher arches, especially if they are shorter besides, even 157 degrees is a bit of a stretch. It is purely a geometric impossibility. I've tried to draw out 159 degrees, and it never works out. The overstand is too high, or the saddle is too high, or the bridge is too short. The point is, I don't even know why the angle is important.

I've read people talking about bows, and how as the angle is increased, so does the pressure. That just isn't the case on a violin string. The pressure is the same for a given string diameter and pitch, regardless if the string angle was 159 degrees, or 152 degrees. It is purely a physical function; tension times diameter at a set length, equals pitch. So what is it that they are after? I don't know. If you know, please tell us.

Neck angles I can see will make a difference in the way they feel when played. If one violin has a neck set at 8 degrees, and another is set at 4 degrees, a player would notice the difference. But what would it be? The left arm might have to be held higher, or lower, the instrument tilted differently, but they both could be played. After a while on either instrument, playing the other would seem strange, until you got used to that one.

Or is there a holy grail there too?

How about bridge heights? If you use 26mm as an average fingerboard projection, a bridge will be about 31mm or so tall. With a higher arch that may even be too high. But something is even more important there. I drew the Strad up with a 32mm bridge and a 16mm arch; a 2:1 ratio. That is the leverage that is forced on the body by the strings. If the arch was only 14mm, the leverage goes up 14% to 2.28:1. If the arch is 18.25mm the leverage goes down 14% to 1.75:1. I'm guessing that would have more effect on the sound and the way the instrument plays than the string angle. Would the higher leverage make the instrument louder? Easy to get moving, but hard to play softer? Am I wrong? Please tell me.

So on to the way I have the string angles figured out for these two:



The problem I see is that when you make the neck flatter, and increase the overstand, it makes it possible to even out the string angles at the bridge. But you can only go so high. It is easier to lower the saddle to even things out, but that makes the included angel tighter. Doesn't it? It seems like everything is conspiring to make the angle more acute, not flatter. Please tell me if I'm wrong.

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