Gore Gilet Design and Build books

[Rienk Ayers]

I was taking a few lessons from Brian Burns, after you had blown through town; his story went that he had another student in the shop, and you took your guitar out and he played it and paid you $xxxx dollars right there on the spot, saying it was the best steel string he'd ever heard. Brian said it was also.

I have a question: the use of cf rods between the headblock and some sideblocks. I'll attach a picture. theory being that you can do away with the utb, freeing up the upper bout, especially with a cantilevered neck,

Is there upper bout sound that can be/should be gotten?

Structurally or acoustically, I don't understand the gap between the side blocks and the top kerfing. I find it hard to believe it will dampen the sound any more than the kerfing already joined to the sides; and structurally, tying into the kerfing makes a lot of sense.

I also wonder about the need for so much CF tubing. the neck joint attachment is under tension on the bottom/back of the guitar, and the top part of the neck block is under compression... wouldn't one pair of CF tubes with the size of block used easily transfer the loads?

I use CF almost everyday at work, and I just don't see the need in this application. I haven't run any analysis on the system, but I would think that a nice wooden rod (or laminate) would do the job just as well, be more aesthetically appealing (it's "wood", like the rest of the guitar) and any weight issues could be mitigated by fine tuning the side blocks.

Personally, I'm fascinated with cantilevered necks and offset sound holes, so I'm not sure how to aesthetically incorporate such compression members... but I'll try to work my way through the books before I bang my head against the wall too much.

[Trevor Gore]

I was taking a few lessons from Brian Burns, after you had blown through town; his story went that he had another student in the shop, and you took your guitar out and he played it and paid you $xxxx dollars right there on the spot, saying it was the best steel string he'd ever heard. Brian said it was also.

Yep, that's pretty much how it was, but he had to check with his wife before he put the $$$ down! It was a WRC/EIR guitar, just like the one shown in many of the construction pics in the book.

The course I ran at Brian's place (the two there were the first two) I've run many times subsequently. On average, I sell ~1 guitar to a student every time I run the course with typically ~6-8 people per course. These guys (well, they're mostly guys) have usually built a number of guitars prior to attending the course (and some are pro luthiers), so it's interesting to think why they might want to buy a guitar when they can build one themselves. Here's some of the answers:

1) I want a "reference" guitar to know when I'm getting close.
2) I don't hear guitars like this very often and I've learnt not to let them "escape".
3) Now I know what it takes to build nice guitars, I know I'll never be able to invest the time and effort, therefore better to buy. (This guy, a one time pro player, actually bought two guitars, a classical and a steel string)
4) My superannuation fund needs a guitar. (i.e. a collector/investor)

Is there upper bout sound that can be/should be gotten?

There's not much goes on acoustically in the upper bout. Smallman pretty well proved that on his classicals, where the upper bout is 3/4" marine ply beneath the top veneer. However, numerous builders tunnel through their transverse bracing to take their longitudinals into the top of the upper bout, so there are plenty of ways of doing things. But think about this:

The sound radiation you get from a guitar is proportional to a/m, where a is the effective area of the top and m its effect mass. It was Prof. Jurgen Meyer, iirc, who came up with that one. m rises faster than a as you increase area because you have to put in more material to keep the deflections under control (deflections increase as the cube of the span). So what you find is that most guitars are too big for their own good. You're better off getting larger excursions from a smaller, lower mass area that is easier to drive and that will give you more volume. If you're after tone, there are many ways of addressing that before I'd go seeking things in the upper bout.

[Trevor Gore]

....especially with a cantilevered neck....

Pretty well all necks are cantilevered, so Dave, are you referring to an adjustable neck (what I often call a tilt neck) or something else? I know Rick does his "gapped hardware" neck joint. Are you referring to that?

[Dave Bagwill]

I should have used a more generic term - any system that keeps the fretboard off the top. I'm not concerned right now about the string angle to the bridge, just the upper bout concept.
I just happened across Turner's picture doing a web search.

[John Link]

Thanks Trevor for your input that your books reflect what you build and what you know relative to the basics. As I said before, they are worth the money. They, along with the Somogyi books, are the ones I re-read the most often.

[Trevor Gore]

I should have used a more generic term - any system that keeps the fretboard off the top.

Ah, OK. You mean the fretboard extension is cantilevered. There's lots of permutations on that theme, from the Stauffer tilt-neck to the Humphrey Millennium. My tilt neck, pic above, is a permutation on the Stauffer theme. Doolin does an interesting adjustable neck, too.

Thanks Trevor for your input that your books reflect what you build and what you know relative to the basics. As I said before, they are worth the money.

No worries, John. I'm pleased you're enjoying them and thanks for the write-up.

[John Link]

As long as this topic has become active again, I thought I would post a tidbit from the "design" volume every now and then. The math can get tedious even to one who likes math (such as myself), but it shows that the authors did a great deal of work to draw relevant studies from a range of well established sources into what affects guitar design. It is way better, in my view, than appealing to vague theories, of which there are many in the endeavor we all love so much.

Tidbit: They cite basic facts about how we hear that affect strategies for designing guitars with appealing sounds. Hearing borders on an illusion when comparing it to the results empirical measurement yields, they say and I believe them. I have known for a long time that (up to a point) loudness makes sounds otherwise the same as softer versions more appealing as long as it is within a certain range of decibels. The book delves into the phenomenon of loudness as it pertains to guitars and finds that the initial attack of a note, coupled with the existence of multiple harmonics above a certain order, leads to the aural impression of satisfying loudness. They suggest lower mass soundboards with adequate flex - but not excessive - are a way to achieve this. Such a soundboard moves a reasonable amount of air and starts up quickly. BINGO. This makes sense whether one follows the math and physics or not, and is noted in plain English. It is also backed up with an analysis of what happens when a single note from a plucked string is recorded and then played backwards, that is, without the initial attack that our brains use to form the impression of loudness. Even though that initial attack is eventually heard, because it comes at the wrong end of the sensation, the note is not perceived as loud. This despite the fact an equal amount of air has been moved during playback of both versions of the sound. I have not done it yet, but intend to follow up with a recording from one of my instruments to experience this for myself. I am not doing this out of doubt, rather just because I want the actual experience. I doubt I ever would have thought to try this without the stimulus from the book.

And so, there is practical info in the design section. If you want appealing loudness, work on getting a faster response to the plucked note. Use their suggestions or develop your own. There is more to it than just decibels.

When Rienk said earlier his brain hurts when reading the design volume I understand. Yet there are a lot of summaries of the nature I detailed above that wrap it all up in a way that I have not seen before. I might post a few others as I re-read the design volume.