Lightweight Bridge

scot

Here is a small photo of a recently made bridge. I started with a large block of wood, then I cut the vertical and horizontal slots with a Bridgeport. Then I cut and shaped the bridge with hand tools. The hollows in the feet were cut with a Dremel tool. The top did break off very cleanly and I had to glue it back, so if you try this at home be careful. I put this bridge on my '84 J-P Favino and it made a big change in the sound. This bridge is very light. Hollowing the feet makes it a lot easier to properly fit the bridge to the top, too.

I originally thought that the large cut across the bridge might make the top surface bow under pressure but that has not happened. All in all I call this an improvement, at least for me.

Larger images at:

http://photos.yahoo.com/scot232001

Best
Scot

Ando

Interesting, Scot. You know violin and contrabass bridges are cut in a way that looks like it's supposed to encourage greater vibration. There's a page here:

http://hyperphysics.phy-astr.gsu.edu/Hb ... in.html#c4

Can you characterize the tonal results?

Cheers,
Ando

Al Watsky

I've weighed all the bridges I've come in contact with .
Sometimes a heavier bridge will sound better than a light one.
Not louder but better.
At least in one glaring example I've found that a heavier bridge can sound much more balanced.
Generally even on the vintage stuff I've handled it between 9-11 grams. The replacement bridges are heavier.
If your making your own. I would use rosewood.
It rings well and its light enough to get the numbers down.
I would not use ebony if I was looking for light.
The data is still coming in !
:-h random emoticon .

Jazzaferri

Interesting...I am about to start my Aria beach selmac's 22gm block on a diet. I will post my observations as the stages progress. First is to get the weight halved. :!!

Al Watsky

I think I have the weights logged in my bench book. If I find them I'll post the various weights of some vintage guitars and some recent hand made instruments from , Favino , Barault,Di Mauro and Dupont.
Also will weigh some Dupont replacement bridges,which increase in weight as the increase in height, no surprise there.
Its a good idea to keep in mind that the modification of the bridge will only slightly change the guitars character , it will not transform the instrument unless the bridge was totally glaringly wrong ,over weight or misshaped . So don't hope for miracles but look for improvements. You will not turn a sow's ear into a silk purse.
Thats a fact known from history. Its the sum of the parts. The character of the instrument is the character of the instrument.

Al Watsky

So here are some weights.
Mystery Guitar(hand made USA) 6.9g
Dupont #3 12g
Dupont #2 11g
Dupont #2 12g
Bauralt 9.2
Guy Theaud, from a Favino 13g a very tall bridge
MDC 60 Dupont 11g

A random sampling, more to come.
Interesting to see that an two identical bridges have a full gram difference.
The Mystery guitar sounded better with an 11g stock bridge , too many overtones in the low frequencies with the lighter bridge .
The hugely tall bridge on the Favino from the guy named Guy was a "professionally" made replacement bridge. Its a very overworked piece of goods , obsessively hollowed out. The guitar was not great, all the bridge tinkering didn't make "the difference". IMO
One thing to note about the Dupont bridges is that they are well crafted and all have plenty of material to work with . Any of them could be 3 grams lighter.
Have a few more to weigh but I think as I have always thought , which is the bridge is one component of a larger system.
The Bauralt guitar has a bridge of an average weight , its not overworked to be lighter. The guitar sounds fine with this weight bridge. So one might conclude or surmise that a guitar with a thin top and light bracing may benefit from a substantial bridge and that a less sensitive instrument with a heavier top and bracing "may" benefit from a lighter bridge.

:question: Random emoticon !

noodlenot

good info Al, thanks a lot.

Jazzaferri

I suspect that bridges are best matched to the rest of the guitar. :peace: by someone who knows what they are doing

bluetrain

One friend bought a used GJ guitar from France and his guitar had a cool bridge. I have no idea how light it was but it looked very light. Carved very hollow, drilled holes and not as wide as the moustaches. Here's a picture of the bridge to inspire.

Al Watsky

That would work. How's it sound on that guitar ?

Jazzaferri

Hmmmm......very interesting...I was wondering about drilling.....if done properly it doesn't weaken race car parts....so it shouldn't weaken the bridge.

Anyone know how much the internal vibration of the bridge is changed and how much that internal vibration matters if at all to the sound. Looking at violin family instruments,the bridges are certainly shaped and opened up.