Rants, Breakdowns and Miscellaneous Ramblings
In the quest for a superb instrument, expectations often play an unfortunate role in affecting the perceived sound. The recent blind listening (and blind playing) tests in France compared Stradivarius and other early violins with some from modern luthiers. All of the professionals involved were very surprised to find that they preferred the newer instruments. I believe that the results would be the same if guitars were used for a similar test. This is not to say that pre-war guitars are not wonderful, but rather that there are modern instruments that would do just as well in an objective test, in my opinion.

In the steel-string guitar world, most builders use the x-braced pre-war Martins as their model of a tonally superb instrument, and strive to equal or perhaps even surpass those Martins. Because all of these makers (including the Martin company, several other large and mid-size businesses, and many individual luthiers) are using the exact same approaches, the sound differences between the many thousands of well built instruments are very small, though very real and important. The result is an inevitable obsession with all of details of the instrument’s construction, no matter how small, as both builders and players struggle to understand what methods will consistently result in a superb guitar. The difference between a very good tone and a superb tone is extremely subjective, and a result of a fortuitous blend of technique, wood quality, and some other factors that each luthier tries to discern and proclaim. As a result, many luthiers promote this or that detail of their construction as essential to the creation of superior guitars.

As a builder and vendor of handmade guitars, I frequently hear fervent discussions about various brands and luthiers, and combining that with some minimal reading of the online discussion forums where obsession seems to be the norm, I would like to offer some thoughts about a few myths and red herrings that are frequently mentionned.

The acoustic affects of a finish are due to two issues, mass and hardness, and both of these issues have been researched enough to have fact-based opinions. The heavier the film that is placed on the soundboard, the greater its detrimental effect on the response. The softer the finish, the greater its detrimental effect on the response. All finishes will continue hardening for years, and in my opinion, that is one of the reasons that age tends to improve tonal quality.

All finishes can be applied thinly, so no one type has the advantage here, except for French polishing as described below.

Nitrocellulose lacquer seems to have a mystique, due primarily to its use on desirable older instruments. It is a beautiful finish when new, and many builders love it because it is so easy to touch up. However, it is very toxic (for the builder) and extremely slow to harden fully. It is brittle, prone to checking, and does not offer nearly the protection of more modern finishes, and protection is the primary purpose of a finish. For best results, it needs a month of drying before buffing, and will take a year or more to get hard enough to resist a fingernail. I grew up using it, but I do not use lacquer any more.

Varnish comes in so many different formulations that it is difficult to make general statements. It is not as brittle as lacquer, and is less durable than modern catalyzed finishes. Violin makers apply it very thinly, which is acoustically beneficial, as they are not subjected to the same requirements for a “perfect” finish as in the high-end guitar world. I offer a varnish that dries harder and faster than most, buffs to a lovely gloss, and has the silky hand feel of most varnishes.

Catalyzed polyurethane and polyester are used by most of the larger companies, and increasingly by individual luthiers. They are extremely durable, highly glossy, and fast to dry. The larger companies’ automated machines and need for fast production resulted in finishes with a thickness that a quality luthier would consider excessive, though Taylor has now invested a lot of effort in learning to apply a thinner film. My standard finish is an industrial catalyzed urethane, with a final average film thickness in the range of 2.5 to 3.5 thousandths of an inch.

Shellac, when applied as a French polish by a skilled luthier, offers the chance of the thinnest and lightest finish, as it does not require building up enough thickness to level sand and then buff. Unfortunately, It is the least resistant to damage from water and other liquids, but it does age into a very hard film. With its very low mass, French polished shellac is a superior finish for high-end nylon string guitars. I do not offer a shellac finish.

Some luthiers and players attribute nearly magic qualities to the use of hot hide glue. Many well known builders do not use it at all. Most will use several different glues on each guitar, depending on the parts being assembled. My opinion is that hide glue offers no acoustic advantage over other properly selected adhesives. However, its great advantage is its repairability; if a hide glue joint comes apart it can be reglued without stripping the joint back down to bare wood. In the only test that I have heard of, 2 otherwise identical guitars were built, one with hide glue and one without. In a blind test, listeners weren’t able to discern any difference.

More than one well respected luthier has said that weight is the enemy, and that lighter guitars are superior to heavier ones. I am afraid I have to disagree with that opinion, as I believe that additional mass in the right places will enhance the tone and power of a guitar. In fact, the only part of a guitar that directly benefits from light weight is the soundboard. Imagine a large bodied guitar built from a heavy dense wood like cocobolo. Now add double sides, solid linings, a rigid neck block assembly, and a neck with a truss rod and internal carbon fiber rods. Put a well designed lightweight doubletop on that body and you will have a very heavy guitar that sings with power and beauty, exploding with sound.

There is a strong tendency, encouraged by many companies and luthiers, to assign absolute tonal qualities to each species of wood. Though obviously there are characteristics of each species that tend to provide expectations of certain responses, the variation within the same species is so large that you are better off ignoring the type of wood used and just listen to the instrument. Due to these variations, I am convinced that in a blind test, most listeners could not reliably differentiate what wood the back and sides of a guitar was built from. If you are ordering a custom guitar, then the best approach is to convey to the luther the type of tone that appeals to you, and show your style of playing, and let the builder go from there.

For example, I can listen to the tap tone of 10 pieces of the same species of spruce, and each will be different, with some extreme variation. These variations can easily overlap with the characteristics of other species.

I also urge you to forget about so called “good combinations” of top and back woods. In the confusing world of infinite possibilities, I know it is comforting to say that adirondack-and-mahogany or redwood-and-walnut or german spruce-and-rosewood will give you what you want, but that is the wrong end to start from. Start with a luthier whose guitar amazed you with its sound. (Buy that guitar if you can!) Then describe to that builder what you like about their “amazing sound” and perhaps suggest how you would modify that sound to get your ideal. Then describe and hopefully demonstrate your playing style. Then you can ask about the woods that you find visually appealing, or that you have heard offer certain tonal qualities. If two luthiers built a guitar of similar body size, using the same wood combinations, the results would probably be more noticeably different than two similar guitars from the same builder that used different woods.

Dovetailed versus bolted neck attachment:
Proponents of dovetailed necks make claims of sonic superiority. Proponents of bolt-on necks claim to be sonically equal to the dovetailed ones, with superior repairability and adjustment. Obviously my adjustable necks are a bolt-on varient, and I encourage one-on-one comparisons between my guitars and any others. With their strong projection and rich tonality, listening to my guitars will cure any dovetail envy. Not to mention the large number of older dovetailed neck guitars that have had the saddle shaved down to the bridge, because it is expensive to reset the necks.