Quilted maple for the back?

[Paul F]

My first post. I am having a mandolin built for me, and need to choose the back material. I love the appearance of quilted maple for the back, but wonder what the impact will be on the sound; I'd rather have a good, balanced sound and sacrifice the aesthetics. How much difference does the back material make? Is it less critical for the neck?
Many thanks for any advice.

[Tom C]

I would let the builder decide.

[Bill Van Liere]

Paul...the figure of the back wood should only be part of the equation in creating a good sounding instrument. The type of wood, Maple vs. other, would have a greater effect. There are many great sounding mandolins out there with non-figured backs and sides.

A side note without mando content; My wife desired to have a small guitar. We went to Elderly Instruments where she was able to try out four or five different Larrivee' parlor guitars. Most of these were curly maple but one was quilted. My wife had narrowed it down two guitars; one curly, one quilted. I listened as she said "I really like the sound of this one (the quilted guitar), but the wood on it seems so gaudy to me." Me, just dying to have a nice piece of quilted in the house, had to talk her into it, saying that it sounded the best and she could not see the back wood as she was playing it anyway, and neither can anyone else for that matter.

[sunburst]

Whether quilted or not, the density and stiffness of the back wood are the things that affect the sound most.
In other words, a piece of Bigleaf Maple that is fairly light and of medium stiffness (likely with quilted maple) will sound similar if carved similarly by the same builder, whether the figure is curly, quilted, or plain.

As to how much the back affects the sound, there's no accurate answer, and I think different builders use the back differently, so that the contribution of the back to the sound can vary from one instrument to the next, and between different builders.

If your builder is experienced enough, he/she can tell you whether he/she can confidently build your mandolin with a sound like you want with the materials of your choice.

[buddyellis]

Quilted maple should not sound much, if, any different than flamed. The difference between the two, really, is the manner in which they were cut up and the species (quilted is usually bigleaf, which can be a 'softer' maple but again that varies from tree to tree, also).

It really depends on the chunk of wood and its density, and in that regard is dependent on the builder using those qualities to get what you want in the instrument out of the chunk of wood. I'd go with what I like best, visually, as sonically, I doubt there's going to be a whole heck of alot of difference.

IMO of course.

-b

[Paul F]

Thank you all for your comments. #I came to the right place. Of course, what I take away is, "It depends...," #and it is just this sort of ambiguity that fuels my quarrel with reality. #My builder suggested that quilted may be darker, and recommended offsetting it with bridge material that would be brighter, but I can see that there may be room to choose the quilted on appearance alone, without an obvious and immediate risk of heavily coloring the tone. #I'll be curious to see what other comments come in.

- Paul

[Rick Turner]

One thought: flame maple will tend to be quarter sawn; quilt will tend to be slab sawn. The quarter sawn wood (or vertical grain, if you're there Bruce) will be a little bit more stable than slab sawn. If that doesn't matter to you, then that's fine. I'd defer to your builder on those issues.

[buddyellis]

It's possible that it could be darker, because bigleaf isnt 'generally' as hard -- it depends on the board, though, and again we are speaking generally, and IMO, in small effects, many of which (in my limited building experience) can be adjusted in the plate building process.

Just as a general guideline, though, the harder the back plate, the brighter the sound, TO SOME EXTENT. Bigleaf is softer than sugar maple. Frankly, I think your choice of strings (and plectrum) has a much larger impact than your choice of backwood (Presuming you aren't using basswood or pine, and even that is relative, because I have some 100 year old yellow pine that sat in the attic of a church in Florida that is some darn hard stuff!). Bigleaf is a PITA to work with, from what I've read, but it looks pretty nice!

Again IMO :-D

-b

[jaco]

When I had mine built I wanted one of those bee-u-ti-ful quilts for the back. Skip (Kelley) had a one piece back on big leaf maple he swore by. I'm glad I let him do his thing. This mandolin is loud and I mean LOUD!!!.

[Jim Hilburn]

Has anyone ever seen a back "warp" from being flatsawn, to the point of causing structural problems?

[Spruce]

Good question.....

[Rick Turner]

There is an interesting point of view of the "why" behind guitar neck resets these days, and that's that the back flattens out as the neck block rotates slightly from the tension of the strings. It is possible that this happens to mandolins, too. Pure conjecture here, by the way, but something to just look at with regard to older instruments and changing geometry. You could have the tops collapsing inward from the down presure of the bridge and the backs flattening, thus allowing the neck block to move. These are slight changes, but enough to change action over the years. Hard to measure without some sort of very precise jig into which you could put an instrument and then make careful measurements over the years.

[Gail Hester]

I’ve used one-piece Big Leaf quilt on several instruments and I really like it. #As mentioned it is usually slab cut and also as mentioned I have found it to be more difficult to work with. #Bending sides on heavy quilt can be a real experience, namely little chunks of quilt figure tend to pop off like little bullets. #

Here’s a chunk of Big Leaf heavy quilt that I hope to get a couple backs from someday. #It is green, just harvested from a local tree that came down in the wind. #The extreme quilt is hard to see in this photo but hopefully you can see the slab cut orientation.

[John Bertotti]

Holy cow that is some serious quilt I love it.

[Dale Ludewig]

Rick- that's an interesting question. I don't know if any data is around to test it. Probably not. But it is an interesting question. I'm not talking about 5 years, but 50-60 or more. I wonder if anyone has any data that would pertain to this- Mr. B. do you have. Or the other F5 historical experts here, of which I am not? I would think that if there was any consistant problem we would have heard about it, but maybe not. I, personally, have not had any problem with slab sawn and aren't most older instruments, Gibson or not, slabsawn?

Bruce- good to see you back. You must have been out hunting wood for awhile?

My personal experience with quilted is that it does tend to be softer than sugar maple (duh), and tends toward a deeper toned back than other woods, but that can all be changed and mixed with the builder. IMHO, one must never forget that the mandolin is a system of combinations. There's a lot going on and I don't think any particular wood or other general characteristic can be accountable for all you see and hear. JMHO.

[sunburst]

I have seen some problems in old Gibsons with flat sawn backs, but not from warping.
The problems I've seen are from shrinking, and are usually at the sides of the head block or the upper body point on F2s/4s. A slab sawn back will move more with drastic humidity changes and put more sheer stress on those cross-grain glue joints than a vertical grain back. The back to block glue joint can fail.

[Michael Lewis]

I suppose each piece of wood is different from most others, but I have been of the mind that wood generally has the tendency to shrink more radially than tangentially. That would mean vertical grain (quarter sawn) would shrink more than flat sawn.

[sunburst]

It's the other way around, Michael. Red Maple has a T/R ratio of 2.0 and Sugar Maple has a T/R ratio of 2.1. That means Maple shrinks twice as much tangentially as it does radially.
That info comes from (where else?) Understanding Wood by R. Bruce Hoadley. There is no value given for other Maples.

I've done the math before, and a 10" wide mandolin back, flatsawn, has the potential to change width by about 3/16" if left for extended periods of time in both extremes of relative humidity that it might encounter. Quartered has only a 3/32" potential. Of coarse, being glued to the rim restrains the back from actually moving that much.

In fact, during a humid time last spring when I couldn't get the relative humidity (RH) low enough in my shop, I was getting ready to glue a back to a rim so I calculated the equilibrium moisture content of the back at the RH of the shop and measured the width of the back. I calculated the width the back would be at the desired moisture content, put the back under a heart lamp until I had that measurement, and glued it on.
That's a poor substitute for better humidity control, but it kept me working!

[Gail Hester]

There is an nifty wood shrinkage calculator online that allows you to select the wood type and how it's sawed. It's interesting to run some numbers and seems to follow John's comments.

http://www.woodweb.com/cgi-bin....rinkage

[Rick Turner]

Yep. That's the way it works, and that's kind of what I was getting at with regard to stability. Also note that wood hardly shrinks or expands at all longitudinally. Old slabby backs that I've seen often do shrink and pop and get weird, and of course it's most evident on unbound backs. But that is across the width. And funny enough, if the backs do flatten out with the blocks rotating, that could be made all the worse by the back shrinking across it's width and pulling the sides in. It's kind of two not-so-good things happening at once.

[sunburst]

Thanks for that link, Gail!
I guess if I thought about it, I could find stuff like that on line myself. That will probably save me some time eventually. It's a lot faster than reviewing those mathematical formulae, looking up the woods, and all that!

[Spruce]

"Bruce- good to see you back. You must have been out hunting wood for awhile?"

My back's been out from lifting too much quilted maple...

On the mend now....

[Dale Ludewig]

Bruce, I feel your pain. My back's been out since before Christmas. Also on the mend now. Not from lifting too much quilted maple.

[Spruce]

Bad blueprints....

[Michael Lewis]

John, thanks for setting me right. I guess I will have to break down and get that book. I am constantly amazed how misinformation is perpetuated by folks that don't really know what is going on, and now I find myself in that category. I don't want to get old, I'm already missing my mind.