Larsongs wrote: ↑Fri May 08, 2020 11:09 am
The OP isn't the only one reading this Thread.. Others may be in search of a better Acoustic.. Just think the information needs to be accurate & hopefully less confusing...
I agree that information needs to be accurate, but you seem to be either missing Larry's point and/or arguing something different entirely.
Larry said that
current-production D-18s and D-28s feature the same bracing, shape, neck, scale length and soundboard. The only differences are the wood of the back and sides, and cosmetics.
A J-45 has a different shape, scale length, bracing, and overall construction as Larry pointed out. That puts the tone-affecting commonalities between the current D-18 & up at "everything but the wood on the back", and the commonalities between the D18 & the J-45 at "they have the same woods."
Construction method is the primary determinant of the tone of an acoustic guitar. This is why any given spruce and mahogany Gibson, Martin, Taylor, Goodall, Olson and Ryan sound nothing alike. Of The woods, the soundboard is where about 95% of wood-based differences come from. Compare a cedar, mahogany, and Sitka spruce-topped guitar from the same builder using the same shape and bracing pattern, then compare three similar spruce-topped guitars but with maple, mahogany, and rosewood backs and sides. The sides are acoustically inert and the back is the only tonal contributer, but even then, construction method determines the degree of its impact because you have rigid-back designs that merely reflect, and vibrating-back designs where wood properties contribute more (Martins are the latter, Guilds are the former, which is why they often used laminated maple in an arched shape).
For an audio analogy, the construction is the source, the soundboard wood is the microphone, and the back wood is EQ. EQ makes a difference, but can't make one mic sound like another, and no mic selection can change what the source you're working with fundamentally sounds like. A ladder-braced parlor cannot be made to sound rich and reverberant by using Moon Spruce and Brazilian Rosewood. An X-braced Advanced Jumbo cannot be made to sound small and boxy by using all-mahogany.
Guitarists regularly fail blind A/B/X listening tests with recordings from same-model guitars where the back and side wood is the only difference, but can reliably tell the difference between a parlor, dread, and archtop.
The old D-28, HD-28 and D18 had different construction methods and sounded quite different. The new ones are built the same with a single material difference and some cosmetic ones. They're far more similar than they are different, and far more alike between them than any of them are to a J-45.
Auditory memory lasts seconds, so we are never truly comparing things if they are not directly in front of us, and vision affects hearing at the level of the brainstem up. Blind A/B and A/B/X comparisons are the only way to get remotely close to objective comparisons (and even then, are far from perfect). I've had the good fortune to have several experiences in my life where I could sit and compare 2-3 dozen guitars from the same builder with A/Bs that differed only in a single variable (scale length, body shape, top wood, back and side wood), and did it blind (in the visual sense, there's no way to blind yourself to the feeling of a medium jumbo in your lap compared to a 00).
Everything makes a difference, including random variation in wood density from board to board. Back and side wood makes the least. It's a consensus among luthiers and my experience bears that out.
The artist formerly known as mbene085.