#1: What is the reason for the usage of 'LAMINATED' body/top bracing in accoustic guitars
#2: Why is bone the prefered material for accoustic guitar saddles/nuts rather than brass,'German Silver', or stainless-steel?
#3Why are Resonator 'saddles' made from wood rather than bone,brass, 'German Silver' ?
#4 Why are 'pin-thru' bridges used almost exclusively on flat-top accoustics? ( I saw a 'pull-thru/top-loader' set-up on an older Taylor and I've never seen another. Does this set-up have an inside bridge plate and why doesn't anybody else do this?) Thanx!
My two cents.
#1. Laminated materials have strength, stability, consistency to ease production.
#2. Bone offered a nice balance of hardness to wear so it does a good job of transmitting vibration while not being too hard on the metal or plastic strings we use to produce that vibration. It is also easier to shape than metal and tends to blend with the color schemes of most bindings. As a personal note, I also don 't particularly like the sound of the brass nut/saddle combinations.
#3. Really don't know why resonator saddles are wooden. Maybe it helps soften the already very metallic sound of a resonator.
#4. In my personal opinion, pin bridges do a better job of transmitting vibration. They also link all of the mechanical support for the bridge into a cohesive unit and do a lot to eliminate the shear forces that come into effect as the strings pull towards the head. There are/have been other guitars designed using a "pull through" bridge design. Ovation has made a few of them plus I've seen lots of old Harmony guitars with them and, of course, almost every classical guitar I've ever seen has one. Yes, these bridges have an inside bridge plate to strengthen the top. I think, over all, steel string tensions almost demand a pin bridge or a tail piece to insure that the bridge doesn't pull off and destroy the top in the process. I've seen a lot of old Harmony guitars with bolts holding down the ends of the bridge because the glue can't/won't do it.
I was given an ovation mandolin that uses a "through bridge" which is bolted down to the top. It wouldn't even begin to hold the tension if it weren't.
On the other hand, I have worked on many many Goya and Levin 12-string guitars from around 1960 with classical bridge which seem to hold together without problems. I think this is mostly a matter of creating a good supporting bridgeplate underneath and of course doing a good glue job.
You also have Takamines and Lowdens as good examples that it works.
As to the transmitting of vibrations..., there are a lot of discussions on forums on the matter of which bridgepin material transmits vibrations best, not to mention the matter of bridgeslotting or not, or straight or conical pinholes. It seems to me the stringthrough bridge is one efficient way of getting rid of that part of the equation.
German Silver is....not silver at all.
It's an alloy of 18% Nickel and 82% copper.
As far as I know, on guitars it's only used for frets. I think a nut made of GS would wear very quickly. I'd bet the Martin you referenced has a replacement nut.
Hope that helps you Keith.
Have a great one (:
I'll take a stab at Keith's questions as well...
1) Strength and lower cost than exotic, traditional tone woods... However... there are exceptions to every rule - some of the finest and most expensive guitars on the planet have what could be called laminated sides. Some of us prefer to call them double sides where the maker is laminating two side woods together, they can also be the same wood, in and effort to get a super rigid, stable rim that does not move as much as traditional guitar construction methods from RH changes. Ervin Somogyi and his many former students/apprentices are known to employ double sides. The point is that although guitars with laminated construction are often considered cheap this is not always the case.
2) Bone lasts very long, is infinitely workable, readily available, inexpensive or cheap... and sonically neutral in so much as it does not "color" resulting tone like some materials such as metals may. For those of us who are wrapped too tight... bone polishes up beautifully with micro-mesh or a buffing set-up.
3) In the musical Fiddler On The Roof (the original... Broadway version) Zero Mostell sings the song that will answer your question - "Tradition!" ;) And no I am NOT that old - someone left that original LP "record" in my collection...
4) The decision to use pin less bridges (it is a pin less bridge that you speak of right) is difficult to understand in each instance what the maker had in mind. Or at least it is for me. I have restored old Harmony Sovereigns that had pin less bridges but for the life of me I can't know what Harmony had in mind or what many of today's makers have in mind when they use a pin less bridge. If I had to guess, and that is exactly what I am doing here... I would say that there is an effort toward and an appreciation for reducing the mass of top components so as to hopefully make the instrument more responsive. Again i am guessing.