Three Piece Backs

[Bo]

I recently purchased guitar with a three piece back.  It is made of Ovangkal of differing hues and it's pretty stunning visually.  I am curious if three piece backs are any different tonally, as compared to a standard two piece.  Are they as stable structurally?

I have read that three piece backs are primarily used as a way for manufacturers to maximize their use of expensive tonewoods.  I'm not sure if that's true, or if they are used primarily to create beautiful looking backs from woods with heavily layered grain.

Bo
       

[Jersey tuning]

The Martin company claims that a 3-piece back is stiffer than a two piece back and thus doesn't have to be braced as heavily; they point to the differences in tonal properties of their D-28(2 piece back) and D-35 (3-piece back).  Bob Taylor claims there is no tonal difference between the two and braces both options the same. 
The D-35 was originally introduced by Martin as a method to use smaller pieces from their diminishing stock (in the late 1960's) of Brazilian rosewood.    But Taylor offers a 3 piece back option purely for cosmetic reaons; I have a 3-piece back on my standard 614ce.

So the answer is, wiser heads than you and I can't agree on the tonal issue.

[timfitz63]

I recently purchased guitar with a three piece back.  It is made of Ovangkal of differing hues and it's pretty stunning visually.  I am curious if three piece backs are any different tonally, as compared to a standard two piece.  Are they as stable structurally?

I have read that three piece backs are primarily used as a way for manufacturers to maximize their use of expensive tonewoods.  I'm not sure if that's true, or if they are used primarily to create beautiful looking backs from woods with heavily layered grain.

Well, I've read the same thing about 3-piece backs (stretching wood supplies), and it makes sense to me.  Whatever the reason for 3-piece backs, I certainly can't distinguish a tonal difference between my 656ce (3-piece back) and a 'standard' (2-piece back) 656ce that I also played.  And in cases where the wood displays some figuring, I think the 3-piece backs can look much nicer and more interesting.

That being said, I've read opinions that some of the Liberty Tree Guitars with 3-piece backs are not as tonally 'pleasing' as the ones with 2-piece backs.  If true (and I've never had a chance to compare any such guitars back-to-back -- pardon the pun ), I would speculate that the effort to stretch the very limited wood supply in this particular case may have involved the use of some wood that was a bit more, well, rotten.  Although a lot of wood was acquired from that Tulip Poplar, much of it was probably of borderline suitability for guitar because of the condition of the tree when it was felled.

[Edward]

Gut instinct (and what I've read in the past from various builders) tells me whatever tonal difference exists between 2 and 3-pc backs are either imperceptible, or differences attributable to the build in its entirity and cannot be isloated to just that one difference.

The simplest reason is the answer: economics.  Multi-piece backs allow the builder, Martin, Taylor, and anyone else trying to procure the nicest cut and figuring, to utilize smaller pieces that would otherwise be relegated to the scrap heap.  If 1-piece or 7-piece backs were superior, we'd be seeing a bunch of em, particularly in the higher-end that could use it as tonal bragging rights. 

The simple fact is solid pieces of wood that have both tonal and aesthetic properties are hard to come by, particularly in large quantities for mass production.  Martin's claim is pure marketing, IMHO.  And while Taylor may "offer" the option for a wedge back, frankly many of their large bodies (witness GS, GO) have 3-pc backs by default; even moreso these days as opposed to Taylor decades back.  And no one had to "ask" for that to happen

Edward

[jjthenovice]

I've heard Bob Taylor speak on this issue: He said it makes no difference in sound. YMMV