Acoustic Guitar Construction

http://www.pacificrimtonewoods.com/Sitk ... Report.pdf

A commissioned report investigating the properties of coarse-grained Sitka - good reading

The summary on page iv., and sections 1-7 are very good, then you can skip to the last page to see an eye-opening (to me) pair of graphs.

Am I reading this wrong or does this report show that the wider the growth rings the greater the ability to resonate? Going over engineering calculations the past 2 days with in-house engineers relating to shear strength formulas of steel under wind loads so maybe my brain is just full.

Interesting. It seems a little counterintuitive to me. I'll look forward to reading the entire study.

Bobby M wrote:Am I reading this wrong or does this report show that the wider the growth rings the greater the ability to resonate?

That's the take-away for me, and what I found so surprising. Another interesting point was the very high ATR for Western Red Cedar - 428 if I remember correctly - though the MOE was fairly low.

I think others has stated that wider spaced grain line material is stiffer than the very tight grain stuff which conventional wisdom has lead us to believe is better. My take on the study is that "the science" will prove old growth whatever (tone-wood) is not necessarily better sounding than the stuff that the timber industry planted 60 or so years ago. BTW Sitka spruce grows extremely fast -- Douglas Fir too.

As a side bar --- anyone having the opportunity to visit the Martin factory museum likely would have notice that some of the $150,000+ guitars have very wide grain line and also some have the center joint at the wider grain -- as opposed to what is common today having the fine grain at the joint.

Dave Bagwill wrote: Another interesting point was the very high ATR for Western Red Cedar - 428 if I remember correctly - though the MOE was fairly low.

This is my experience using WRC. It is not as dense as spruce, my WRC tops are typically thicker than my spruce tops. They can be thicker without weighing more than a spruce top. They sound great as well so the very high ATR for WRC validates my experience.

Thanks Dave. I love reading studies like this.