Tone wood Backs

[speacock]

I've always been curious why tone woods are not also used for the back in higher end instruments. We all know what a difference it makes to hold your mando away from your body or use a tone guard. Would this principle not also be enhanced by the use of spruce or cedar for the back?

Just thinking out loud.

[multidon]

First of all, the woods that are usually used for the backs and sides of instruments are tonewoods too. Clearly, they resonate. You can feel the vibrations all over every part of your instrument. Or at least you should. The only difference is that they are hardwoods rather than softwoods. The combination of softwood on the top and hardwood everywhere else is tried and true. The formula goes back to Golden Age Italian violins and even further back than that. The softwood of the top acts as a soundboard, similar to the cone of a speaker as it drives sound forward. The hardwood back and sides act as the speaker enclosure, helping to reflect and direct the sound as well as vibrating sympathetically and adding a bit of its own character to the overall sound. Also, the hardwood back is harder and more durable than softwood would be, and the back is generally subject to more wear and tear than the top. Just look at how many instruments are “mint” except for the “buckle rash” on the back.

[Marty Jacobson]

Two words:

Tradition

Appearance.

I'm personally jonesing for a nice mandola with curly redwood top and back, with curly maple sides and neck. It's gonna happen.

[Bill McCall]

It’s not uncommon to have all koa or all mahogany instruments. They sound fine.

Spruce for the back may be a little too soft for durability and may need to be too thick for good sound.

[Marty Jacobson]

Spruce for the back may be a little too soft for durability and may need to be too thick for good sound.

Brian Dean's Labraid Grand Concert models have a carved spruce back which is about 1.3mm thick.
Kermans have an internal back, spruce as well I believe, which is 2mm thick or so.
Both of those handle durability and tension by having a secondary back made of hardwood outside of the "real" spruce back.

[fscotte]

Softwoods have been used for backs on many types of instruments.

It's more about durability rather than tone.

[speacock]

Kermans have an internal back, spruce as well I believe, which is 2mm thick or so.
Both of those handle durability and tension by having a secondary back made of hardwood outside of the "real" spruce back.

I was curious about that as well. Seems like a more elegant solution than a tone guard, but also a more complicated build.

[j. condino]

2005 Condino mandolin

Douglas fir top, back, sides, blocks, & neck.

99% recycled materials and parts; approx. $34 total cost to build....