A quick google search will offer you perspectives on tone woods from manufacturers, boutique builders and wood suppliers. These comments are from my own perspective as a player and are purely subjective.
It’s been a privilege to be associated with C.F. Martin & Co Guitars (est.1833).
My signature Martin OM (Orchestra Model) guitars were conceived as modern performance instruments adapted from 1930’s vintage specs. Modifying string spacing, adding a cutaway and offering a selection of tonewoods, I’ve aimed at putting a custom, but value-added personal stamp to a classic design.
In the course of ten years, we’ve collaborated on editions in Mahogany, Brazilian Rosewood, Indian Rosewood, Madagascar Rosewood and Big Leaf Maple. All have Adirondack (Red) Spruce tops. They are built to the same basic specifications, so any differences in weight and sound are characteristic of the woods used in that specific instrument. I tour and record with these various incarnations.
The top itself is a significant component of the the tone of the guitar, along with the body dimensions.
Adirondack spruce (Picea rubens) has a ‘megaphonic’ quality, with a great deal of headroom and can easily handle a hard attack. The string gauge makes a difference – I’m using a ‘true medium’ set with .013″ on top and a .056″ on the bottom. The extra tension makes the top ‘work’ and allows for a wide dynamic range. I find Sitka Spruce typically has an ‘in your face’ kind of sound, with less of the fundamental. Cedar can be warm and rich, but with steel strings it tends to have fairly low headroom and can get ‘crunchy’ when attacked.
No doubt, an experienced luthier will say that one cannot visually tell the stiffness of the top. In my experience there seems to be a correlation between the grain width and the sonic signature. The wider grain Adi tops seem to have more ‘oomph’ in the sound. However, this is based on a ‘mere’ 10 years of use, so it may simply be that the wider grain ‘opens up’ faster.
Body woods exhibit a range of ‘velocity of sound’ which is the extent to which the body, specifically the back, reacts to the vibration within the sound chamber.
Brazilian rosewood (Dalbergia nigra) is the traditional wood for high-end guitars. In use since the 19th century, it offers a powerful combination of warmth, projection and treble presence. Paired with Red Spruce, forward-shifted X-bracing (characteristic of 1930’s Martins), 25.4″ scale length and a 1 3/4″ nut width, it represents a ‘holy grail’ combination that, along with age, makes the pre-WWII Martin guitars so desirable.
Since Brazilian was placed on the CITES http://www.cites.org/eng/app/index.shtml appendix I of endangered species, it has become increasingly expensive and reserved for special editions, custom and boutique guitars. There are luthiers that have some stunning examples of ‘stump wood’ with some amazing figuration, but the traditional straight-grained stuff is hard to find. In 2003 Martin did a limited edition of 50 (plus 4 prototypes) of my OM28B LJ. Very cool guitars – very 1930’s sounding, especially with a flatpick. Brazilian has a smooth compression and doesn’t overdrive. Much like Red spruce, it keeps giving back, the harder it gets pushed.
Madagascar rosewood (Dalbergia baronii) In the last decade, Madagascar rosewood has become recognized as a close relative of Brazilian, while still having its own character. It has a lush woody tone with less of the ‘ceramic’ tap tone of Brazilian. Although not yet on the CITES appendix I list, it has, like many Malagasy rainforest products, fallen victim to the political and ecological issues that exist on that island. I also have a 12- string version that is quite amazing. Typically 12’s come in larger body sizes, but the OM body is well balanced and the Adi top responds well to the extra string tension.
Indian rosewood (Dalbergia latifolia) sounds ‘denser’ than the other common Rosewoods – it’s a characteristic of having a higher ‘velocity of sound’. There is a warm, chocolate-y low mid-range that embraces the player. The back is working quite hard to contribute to accomplish this, and, to my ears and fingers, it does this at the expense of projection. Coupled with Sitka spruce, which contributes less deep bass than Red spruce, it offers the more-than-serviceable combination that is offered in many modern guitars. I like it also with cedar – the slightly ‘honky’ tone of a driven cedar top, blends nicely with the ‘wetness’ of the Indian. However, as I play with no right hand nails, just fingertips, I find Indian typically a little too dense for my technique.
Mahogany Martin build their mahogany (Sweitenia macrophylla) guitars to be quite light, which seems to contribute to the ‘airy’ sound and ‘woody’ clarity when fingerpicked. Played hard, ‘Hog’ has a quick compression with a characteristic overdriven ‘bark’, which gives it a cutting tone for flatpicking. It’s my favorite for writing and I have recorded more with this wood than any other. It’s also typically used for the neck, being quite stable with consistent sustain. There have been various types of mahogany family woods used in guitar-making including sapele and khaya Ivorensis, but macrophylla is a ‘genuine’ mahogany.
Maple I’ve been quite fond of characterizing the various body woods like wines, with Brazilian being the most Cabernet-like and mahogany perhaps being more of a Chardonnay…… However, I’ve had a harder time so categorizing Maple.
I chose Big Leaf Maple, as being less hard than the European varieties. Of all the woods I’ve discussed, it has the lowest ‘velocity’ and functions to project the tone without much coloration. From the playing perspective, it doesn’t ‘fold back’ to embrace the player, but rather enhances the articulation of the top with little color or compression. Playing without fingernails, I don’t need to work overcome the Rosewood ‘cushion’. The two-piece neck is made from North Eastern US Maple which provides a nice sustain and stability. My goal was to emulate the musicality of the orchestral string instruments, but in a small bodied flat-top guitar, rather than the archtops or jumbos that Maple is typically used for.
There’s a common expectation that a maple guitar is thin-sounding, but an Adirondack top has a full-frequency spectrum so that it is not an issue in these models. In respect of its transparency, I’m leaning toward spirits, perhaps Vodka, rather than wine……There’s an excellent string-to-string balance and the bass and trebles separate well within the musical texture. It also maintains a strong presence within an ensemble.
It makes a powerful stage guitar, tending to project what I put into it tonally, without coloration. I have used it unamplified in a small auditorium and while it doesn’t ‘feel’ like it has the low-end support that rosewood provides, it fills the room nicely across the frequency spectrum. Amplified, it puts out a clean precise tone.
Koa Finally, for a limited edition of 25 (in collaboration with Wildwood Guitars in Colorado), the Martin custom shop produced a koa version. Designated as an OMC-44K these are intended to be ‘presentation’-grade instruments. Style 44 designates Martin’s highest grade of wood. The only guitars in the series with all-hide glue construction and a specific intention to use light-weight woods. The Spanish cedar neck is a legacy of guitars Martin built prior to 1920 when mahogany became the principal neck wood. It brings an ‘airy’ quality to the sound that complements the smooth high-end that koa produces. Hide glue is an upgrade that Martin have only recently begun to offer and brings the extra resonance and touch sensitivity associated with their vintage instruments.
Koa seems to have the warmth of a rosewood, the woody-ness of mahogany, the clarity of maple and the sustain of a vintage Les Paul……Perhaps an aged single malt Scotch will serve as a respectable metaphor.
There may be a few of the earlier guitars in dealerships, but the Koa is the only one currently available.