Koa vs. Mahogany

beatbird · #1 08-31-2023, 08:23 AM

I am probably going to commission a custom guitar at some point in the future and I thought I would start a thread in the custom shop where there are some very knowledgeable builders and connoisseurs of fine acoustics.

I have been wondering about Koa as it relates to the tone of Mahogany. I have heard everything from Koa has a tone very close to Mahogany or that it is closely related to Maple tone wise. I really enjoy mahogany, but feel that if I do go custom I would like to maybe branch out.

Obviously the builder, bracing and top wood make as much a difference as anything, but I am looking for a more general response. What does Koa typically bring to a guitar all other things being equal? For instance lets say you have to identical Gibson style slope shoulders, one with Mahogany, one with Koa. What would the differences?similarities be?

I wonder what the builders and high end custom owners in the custom shop think about Koa as a tone wood? How does it sound on larger (000 and above) guitars, when paired with spruce tops?

If someone is looking for a warm sounding guitar is koa the way to go or is there somewhere else to look?

Thanks

SprintBob · #2 08-31-2023, 06:41 PM

I have a Jason Kostal OMC that is built with master grade Koa on the back and sides and German Spruce for the top.

If you had three German Spruce topped guitars (with the spruce from the same tree), and you built one with EIR back and sides, one with Koa, and one with Mahogany, I believe the Koa guitar would fit somewhere between the other two tonally. Its low end would tend to be less bassy and smoother than the EIR guitar but would have more sustain/reverb than the mahogany guitar. All three would have pretty bright trebles. My real world experience is living currently with my Kostal and a superb Froggy Bottom H-12 with Adi top and EIR B/S and formerly a Collings 0001A that had mahogany B/S and Sitka top.

Cocobolo paired with spruce would also be similar to the Koa/spruce but swayed more towards the spruce/EIR combo IME.

Your final choice could also be greatly influenced by what type of playing you do.
With the right builder, any of the combos above can do anything for you so it could come down to aesthetics.

Hope this helps.

The Bard Rocks · #3 08-31-2023, 08:03 PM

I don't have enough experience with Koa to properly answer - except I have read a lot about it and my takeaway is that it tends to be on the Rosewood side of Mahogany - AND that it has a greater amount of variance than most tonewoods. It's one where you want the builder to be pretty experienced with it to get an instrument that realizes Koa's potential.

K20C · #4 08-31-2023, 08:46 PM

I’ve previously owned a K20c which sounded thin and had no volume and a Martin 00-37ksm which sounded dull and dead. I currently have a K65c which sounds glorious. I’ve played many koa guitars over the years and was not impressed by any of them. They remind me of maple guitars in the way they sound. I would not buy a koa guitar unless I had the opportunity to first play it.

justonwo · #5 09-01-2023, 12:19 AM

Hard to say for sure. I’ve owned and played a fair number of koa and mahogany guitars. I don’t hear massive differences. A builder that has built with a lot of both probably has a better feel for the differences, but in my experience the differences are subtle.

Bob Womack · #6 09-01-2023, 03:54 AM

I'll bite. I've got two koa Taylors, a 1999 K14c koa/cedar and a 2000 "Legends of the Fall" 314kce koa/sitka. I've got several EIR/spruce guitars and a couple of sapele/sitka guitars. Sapele is a replacement for mahogany that has a slightly more pronounced mid and a little upper-mid kick when compared to mahogany.

Firstly, koa is quite variable. In my experience, lights sets tend towards a resonant and cheerful (bright) sound and heavier sets tend towards more of a fundamental focus.

Then to the basic nature of the wood. In my experience, koa isn't as round and bassy as EIR and isn't as brassy as mahogany. It has more fundamental than mahogany and isn't mid-scooped like EIR. For example, the K14c is extremely light and has a bright, clean bell-like tone. Its cedar top moderates the upper-mids so you have fundamental and a sweet far-upper-end that isn't strident at all. In fact, many people comment on that very characteristic. While resonant, it isn't very bassy. It has long sustain. The 314kce, on the other hand, is heavier and is more midrangy than the K14c and has the upper-mid twang you'd expect from sitka. It is less resonant and has less sustain.

Sorry for the frou-frou descriptions. Just trying to reach beyond the basics.

Bob

SprintBob · #7 09-01-2023, 05:23 AM

Regarding the variability of koa, Jason Kostal told me it’s about the age of the wood. Koa matures quite fast so it is a sustainable wood source which is harvested when the tree is young so most of the old growth koa that is left is hard to find since I believe it all still comes from Hawaii and has to be grown above 5,000 feet. Taylor will tell you that their koa guitars need to get played in because I think their koa source is that relatively young wood. Jason sources his koa from a company in England. You might note on many custom builder’s sites, the upcharge for getting the old koa is relatively expensive due to supply and demand.

Martin also has offered limited editions of 000-41’s and 000-28’s that were all koa construction that I heard were worth taking a look at. I’ve seen them listed at higher end shops and on Reverb.

Bill Kraus · #8 09-01-2023, 06:37 AM

Quote:

Originally Posted by SprintBob

I have a Jason Kostal OMC that is built with master grade Koa on the back and sides and German Spruce for the top.

If you had three German Spruce topped guitars (with the spruce from the same tree), and you built one with EIR back and sides, one with Koa, and one with Mahogany, I believe the Koa guitar would fit somewhere between the other two tonally. Its low end would tend to be less bassy and smoother than the EIR guitar but would have more sustain/reverb than the mahogany guitar. All three would have pretty bright trebles. My real world experience is living currently with my Kostal and a superb Froggy Bottom H-12 with Adi top and EIR B/S and formerly a Collings 0001A that had mahogany B/S and Sitka top.

Cocobolo paired with spruce would also be similar to the Koa/spruce but swayed more towards the spruce/EIR combo IME.

Your final choice could also be greatly influenced by what type of playing you do.
With the right builder, any of the combos above can do anything for you so it could come down to aesthetics.

Hope this helps.

I've built a fair amount with koa and I would have to agree with what SprintBob say's here. In regards to a koa comparison to maple, I tend to think of a koa guitar as having more overtones and a bit more in the bass end than maple.
Here is a link to a Youtube video of a OOOO size guitar of mine with Sitka spruce and koa back and sides that is at Carter Vintage Guitars. It is a good example of a Koa/Sitka sound in a bigger guitar.
https://youtu.be/-mzLu2MrRCE

beatbird · #9 09-01-2023, 08:12 AM

Quote:

Originally Posted by Bill Kraus

I've built a fair amount with koa and I would have to agree with what SprintBob say's here. In regards to a koa comparison to maple, I tend to think of a koa guitar as having more overtones and a bit more in the bass end than maple.
Here is a link to a Youtube video of a OOOO size guitar of mine with Sitka spruce and koa back and sides that is at Carter Vintage Guitars. It is a good example of a Koa/Sitka sound in a bigger guitar.
https://youtu.be/-mzLu2MrRCE

Thanks for your input. I actually came across that video yesterday and watched it while searching for koa guitars on YouTube. That is a beautiful and great sounding guitar!

All these responses have me thinking that maybe a basic wood like EIR or Mahogany might be what I should be going for. My only acoustic at this point is maple and while it is a fine guitar that I really enjoy, I don't want another guitar that overlaps that space tonally. I'm really looking for warmth like I am used to with mahogany but with a bit more bass.

iim7V7IM7 · #10 09-01-2023, 07:17 PM

I own two guitars with Koa back and sides (a smaller 00 and a larger J-185 size). I will caveat my comments that guitars sound like their maker’s signature timbre and are also dominated by the tone of their soundboards.

Koa sounds contributes neither like rosewood nor mahogany (sorry).

Compared to Mahogany: To my ear, Koa has more woody airiness and sparkle to its high end than mahogany, a flatter overall response with less predominant midrange and with playing time, a bit more bass response.

Compared to Rosewood: It adds less blooming bass response, overtone content and contributes to sustain a bit less than rosewoods do. It has a less scooped, flatter midrange, more like woods like maple and walnut.

jrdavies · #11 09-01-2023, 10:52 PM

At one point I had three guitars from the same maker. One with a Sitka top and Mahogany back and sides, one with a Sitka top and Maple back and sides and one with a Cedar top and Koa back and sides. The Mahogany and Koa guitars sounded similar but the Koa Cedar combo gave me more of what I liked about the Sitka Mahogany combo. I didn't think the Maple guitar sound similar to either. But that is more likely and expression of my preference than anything else.

I have never commissioned a guitar but I suspect a skilled luthier can figure out what you're after and get there with any wood combo you choose. I think the tricky part is describing sound.

I seem to remember reading an admission by a very good luthier that it took him several years to discover that he and a very knowledgeable store owner/performer were using the same words to describe different things.