Back and side woods vs top wood…what does the back sound like?

[RussellHawaii]

Hi All,
If the top wood is 80% of the sound (as far as wood contributes to it), how would we ever know what a mahogany or rosewood back really sounds like? Wouldn’t the effect of the topwood hide any noticeable effect from the back?
I thought I knew that rosewood has certain qualities, and mahogany different ones. My latest guitar is mahogany back and sides, and I would never have guessed that from hearing it. It is deep, glossy and shimmery, and has a natural reverb to it. One of my koa backed guitars is similar. (I do have a mahogany dread that ‘sounds like mahogany.’) So all preconceptions are challenged. This is a new builder for me, so of course it’s not apples to apples. But still…
I realize the luthier has the biggest effect on any guitar, so I don’t need to be told that.
What does a back wood sound like? How would (wood?) we ever know?

[dnf777]

I think you hit on a very good point. There are general agreements on how certain woods are expected to influence tone, and they may be true to various degrees....but Ive heard so many stark exceptions (some good, some bad, some stellar) that I put more emphasis on the builder, their voicing abilities, and somewhere down the line...wood species. IOW, I judge guitars like I judge people...on individual merit.

[kmtyb]

I been searching for my "tone" this year and found it on most Martins with forward shifted scalloped x bracing. I learned builders are more important than woods. Try many guitars as possible till you find the "one".

[merlin666]

There is general agreement among guitar marketers, review authors, and many members of AGF that there are systematic and reproducible contributions of body wood type to the sound. I have to admit that I was never able to hear any of that in person though.

[Bushleague]

Originally Posted by kmtyb

I been searching for my "tone" this year and found it on most Martins with forward shifted scalloped x bracing. I learned builders are more important than woods.

I'd deffinately agree with that, but woods for sure play a big part. And I dont know that I neccessarily agree with the 80% top wood part. For instance, while wasting time in some guitar shops on my last trip to the city, to my ear the tonal difference between a Rosewood and Mahogany backed Larivee (both sitka spruce tops) seemed at least as drastic as the difference between spruce and cedar topped Godin guitars, with identical B/S woods.

I dont know if thats an apples to apples comparison, but as far as I'm concerned it did demonstrate that B/S tonewoods can lend a fair bit to the sound of a guitar.

[fartamis]

Originally Posted by Bushleague

I'd deffinately agree with that, but woods for sure play a big part. And I dont know that I neccessarily agree with the 80% top wood part. For instance, while wasting time in some guitar shops on my last trip to the city, to my ear the tonal difference between a Rosewood and Mahogany backed Larivee (both sitka spruce tops) seemed at least as drastic as the difference between spruce and cedar topped Godin guitars, with identical B/S woods.

I dont know if thats an apples to apples comparison, but as far as I'm concerned it did demonstrate that B/S tonewoods can lend a fair bit to the sound of a guitar.

+1

There is such a difference in sound between a mahogany back and sides compared to rosewood that I too doubt that this is only 20% of the sound. And the same goes for the sound difference between solid wood versus laminate that I doubt the top alone makes 80% of the sound.

[Misifus]

This stuff doesn’t happen in a vacuum. It all works together. The only way to get a handle on the tone of hog, or rosewood, or Maple, Koa, what have you, is to build guitars with those b/s woods. If you build them in a number of different sizes, and with different top woods (think cedar) gradually you will develop a sense of the effect of the various b/s woods.

For the consumer, I guess the best approach would be to play a lot of guitars with different woods, different styles of construction, different sizes and you will gradually develop your sense of the effects of the various factors.

As I said, none of this can really be heard in isolation. You can’t really “hear” mahogany, or maple, etc. by themselves. They can only be heard in combination with all the other factors.

[FingahPickah]

Originally Posted by RussellHawaii

Hi All,
If the top wood is 80% of the sound (as far as wood contributes to it), how would we ever know what a mahogany or rosewood back really sounds like? Wouldn’t the effect of the topwood hide any noticeable effect from the back?
I thought I knew that rosewood has certain qualities, and mahogany different ones. My latest guitar is mahogany back and sides, and I would never have guessed that from hearing it. It is deep, glossy and shimmery, and has a natural reverb to it. One of my koa backed guitars is similar. (I do have a mahogany dread that ‘sounds like mahogany.’) So all preconceptions are challenged. This is a new builder for me, so of course it’s not apples to apples. But still…
I realize the luthier has the biggest effect on any guitar, so I don’t need to be told that.
What does a back wood sound like? How would (wood?) we ever know?

I believe it's true that the top wood makes a big difference, i.e., - play an Eastman E1D (Sitka) vs an E2D (Cedar) ...

Re: back & sides - To my ear, what matters is that there is also a noticeable difference. I'm less interested in a percentage of tone or a measurable set of frequencies, etc. that back & sides contribute.

Many times I've A/B'd a standard D18 vs a standard D28 of the same year and noticed a significant difference.

I love how Larrivee offers variants of the same Sitka top model - i.e., OM-03 (mahogany), OM-03R (rosewood), OM-03W (walnut) - not just for esthetics - but because to many players they sound different enough to offer real choices of the same design.

[Alan Carruth]

As far as I can tell (and I've tried!) it seems to be impossible to make guitars with 'identical' wood that sound the same. From my experience small variations in the density and stiffness of the top from one place to another make most of the audible and measurable difference. It's really too bad that's the case, because if you could make identical guitars then it would be easy to isolate variables and we could actually settle some of these questions. As it is...

The 'Leonardo' project has been looking at the effect of different B&S woods, mostly comparing traditional IRW with local European substitutes, such as walnut, maple, beech and so on. What they find is that in blind tests people have no preference for IRW over the others, but when players or listeners can see the B&S they prefer IRW by about 3:1, iirc.

In terms of tone, I've used a lot of different B&S woods, and it seems to me that the most important variable is density, followed (maybe closely) by damping. Dense woods that 'ring' a long time when they're tapped, such as BRW and Pernambuco, are widely felt to be 'the best'. However, I note that African Blackwood and Morado, both dense woods with fairly high damping (short 'ring') also make excellent guitars. The woods that sound 'different' from the rosewoods are ones with (generally) lower density and/or higher damping, such as maple, mahogany and koa. Keep in mind that damping loss only happens when something is moving, and a heavy back is hard to move.

As always with the guitar, this is a complicated question, and, as I say, it may well be beyond resolution as long as you're talking about wood. Too many variables...

[TwangGang]

In the first line of the OPs post he asks - how would we ever know what a mahogany or rosewood back really sound like? In his last line he asks again - what does a back wood sound like?

Well no two guitars made of the same woods sound identical as there are many factors involved like bracing and finish etc. But my answer to his question is just play them and listen. Take for example two dreads with Sitka tops, one with mahogany b/s and one with rosewood. Play them and hear the difference. Since most other factors are the same the main variable is the b/s wood that is causing the difference in tone.

[mcduffnw]

Originally Posted by kmtyb

I been searching for my "tone" this year and found it on most Martins with forward shifted scalloped x bracing. I learned builders are more important than woods. Try many guitars as possible till you find the "one".

Yes! You are absolutely right...AND...also...the "Soundbox"...the body size and shape and widths and depths and the top and top bracing, sides, and back and back bracing, and how all those pieces go together and work as a cohesive unit to produce tone is ever so much more important than the type of woods used to build the soundbox.

This all becomes very clear to a person, if you ever have a chance to participate in a really well controlled blind listening test. All your pre-concieved notions fly right out the window...mine and everyone else's in attendance certainly did.

If you have never done so...check out the "Leonardo Guitar Research Project" on the web and listen to audio test, and then watch the video version of the same test. Also a REAL eye and ear opener!


duff
Be A Player...Not A Polisher

[LakewoodM32Fan]

Don't forget what our friends at Kinnaird Guitars in Nacogdoches, TX did in terms of making "as close to the same instrument" as they could with the differences being primarily in the back and sides: EIR, mahogany and maple.

https://www.acousticguitarforum.com/...d.php?t=594605

Don't skip to the end (the non-blind test part). Just like Duff said, it may break some (or a lot) of your preconceived notions of how stark a difference the back and sides make. They all sound remarkably close, which goes to show that the builder and their technique goes a long way in making the sound. And of course the topwood which most agree contributes way more to the tone than the b/s. I'm sure if they threw in a cedar topped guitar that one would have been easier to identify.

[mercy]

When I was young and ignorant I bought a martin dread with lamd back and sides, total disappointment. Some years later I bought a standard and total satisfaction.
Then there is the comparison of a x18 and x28, total difference in tone.
The point is the back and sides do make a difference. Ive read so many times that it doesnt, but it does to me and Im the one that counts.

[raysachs]

Originally Posted by kmtyb

I been searching for my "tone" this year and found it on most Martins with forward shifted scalloped x bracing. I learned builders are more important than woods. Try many guitars as possible till you find the "one".

I have two Martins described on the website as having X-bracing, so ostensibly the same in that regard. One is an 000, one is a slope shouldered 00, which is dimensionally closer to an 000 than an 00. One has rosewood back and sides, one mahogany. I’m sorry, but the rosewood B&S guitar sounds very different than the one with mahogany. And in ways I attribute to those materials. The mahogany B&S guitar is very fundamental and woody sounding. The rosewood B&S guitar is much more lush sounding, with lots more sustain, and generally brighter too, but still warm. The slightly smaller guitar is somewhat louder, which I attribute to having an Adirondack top vs Sitka on the 000. But with these two guitars, at least, they live up to all of my preconceptions about mahogany vs rosewood. I can almost always tell which I was using on my recordings, except in those rare instances when the acoustic guitar is really obscured by an electric track or something else…

-Ray

[Bax Burgess]

Lam back and sides make a consequential difference?

Spruce tops - Taylor 110e (mahogany) and 210e (rosewood), both with tusq saddles and ust removed, new hard plastic pins reamed to fit, bridge slot floors flattened, saddle underside flat with edges rounded. Elixir 80/20 Poly 11-52 on the 110, Martin Lifespan PB 11-52 on the 210.

Both have the same Taylor zing in the mids and trebles, the 110's bass, firm otherwise, is hidden in strums, the 210's bass is always present.