Official Luthiers Forum!

No real qualification here but I have always struggled with the validity of the process some now term as "Tap Tuning".

I really think that a terminology issue has crept into the language lately because despite what builders have been calling it for years, what most of us are actually doing when we say we are "tap tuning" could more accurately be described as "Tap Assessment"

To tap and assess your progress for a treble or bass response or maybe more sustain or what ever else it is that you as a builder may be listening for is one thing and indeed this would seem a perfectly valid and necessary part of a build.

In fact, the ability to make an accurate assessment of your progress from this process, as already mentioned in the posts above, can only really come from experience. This aspect of the craft coupled with the builders own understanding of material selection is probably one of the main factors pushing forward their own progress.

Also, I can understand the benefits of a skilled luthier such as Scott van Linge hot rodding an already completed instrument through the sound hole, taping, feeling and shaping their way using their knowledge and understanding to "assess" the instrument and obtain the most from it.

Where I have problems with the process now termed "Tap Tuning" is when I hear or read that the top and other individual components should be "tuned" to a particular key or pitch in the belief that once these components are combined together, they will compliment each other and achieve a superior outcome.

To me this simply has no logic, it just cannot work like that. Once you introduce one to the other with a layer of glue, they both change and loose the properties you originally tried to achieve.

As Al Peebles so quaintly put it "the joke goes on".

Myself, I feel that Mr C is pretty much on the money with his 4 points and taping to ACCESS the best response whilst staying within that formula is a tool that, according to his book, Mr C has used himself for a very long time....Ahh but that tap "TUNING", now that is the oil of a completely different animal if you sssssssssee what I mean.

Cheers all

Kim

I kind of like Bill C's practical bent and it's probably good to consider that
he knows the people coming to him for advise are less experienced,
amateur builders. Advising them to stop worrying about something that
they can't get any clear instruction on is probably wise. I looked at his
page the other day and iirc, he said he does tap the top and listen and
gets some sense of it by doing so. What he mostly scoffs at is the idea of
individual component tuning.

I know of no one who has heard one of his guitars, though.

There is a logic to Kevin's method. Those who are bothered by the word
'tuning' could think of it as being about stiffness, which relates directly to
pitch. What I hear from Kevin's method is that he will use stiffer braces
on a more flexible top, and vice versa. I agree that building well has a lot
to do with balancing the tonal tendencies of different parts of the
construction, so this makes sense to me, even though I don't work by
tapping braces. I try to get consistent, stiff brace stock and adjust the
brace size and shape to balance my perceptions of the top, fit the size
and intended tonal balance of the guitar, etc. I do this intuitively (which
certainly does not mean without thinking--just without patent formulae,
trusting the wetware to be calculating away while I work in ways that are
not transparent to me), but I don't see it as disconnected from what Kevin
does. I haven't read Siminoff's book, but I am skeptical about tuning
braces to pitches and then to chords, which is what I have heard he says
to do.

As for poor Natelson: I imagine that he and Cumpiano, young luthiers,
finally got their book done and ready to sent to the publisher, when it
occured to them that they needed to choose which name went first.
Perhaps they went alphabetical. Or perhaps Natelson graciously said,
"You go first, Bill." Little did he know that he would be dooming himself
to obscurity. In the future he will be the answer to a luth-trivia question.
No wonder he isn't building any more. Remember him if you ever co-
author a book.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Howard pretty much nails how I feel about a good deal of the "tuning" that some people advocate, the minute you join two pieces of wood a number of factors come into play. You increase the overall mass of both, you have now added more complex areas for vibrations to travel through and you have at some level introduced other external pieces (such as the glue used to bond the wood).
To make all this MORE complex it all changes when you apply the pressure of the strings across the top and even more when you add finish....

Now some of this could be considered non-impactive (especially the glue), however anyone who has spent time carving braces while tapping and listing the whole time can tell you that even the smallest amount of wood removed can be easily heard by the human ear.

I don't do any type of scientific measurements of my tops before I use them because in my *opinion* (just wanted to make that clear) everything changes sooooo much when you finally get it all glued up. That being said, I do think that the work of people like Mr Carruth and Brian Burns and others is invaluable to use as a tool to set yourself a base working standard. Like Al said he built two identical guitars and they both sounded different, so even if you measured everything to the gram, copied patterns etc etc it's still not assurance of a consistent sound.

I currently don't employ any scientific measurements to my tops today but it's on my to-do list going forward.

Cheers

-Paul-

_________________
-Paul-

Patriot Guitars

To throw in a historical perspective, tap tuning has been around for hundreds of years and always played a role in violin family building where the plates were not flat but carved.

For a violin it is not a matter of a specific thickness as the top and back are graduated. When thinning a violin it is part removing enough stock to increase resonance and sustain but also structural in that the top has to be able to support the downward pressure of the bridge.

Violin family makers would use a system in that by tapping on various parts of the luthiers head they could compare that tap tone to the corresponding overtone or fundamental heard while graduating. The goal is an evenly graduated top with no weak spots and without overtones that would work against the main resonant nodes of the instrument.

It is not as much a matter of snake oil as it is tuning the ear to hear the differences in the tap tone...no matter how good you do at it there is still a subjective difference in what you hear from day to day. That is why the use of chaldni "glitter pattern" tuning started with violin family builders and then made its way into guitar builders use...it is an attempt to able to measure in a finite way what otherwise is subjective.

Kevin's purposeful separating the tops and brace stock into like frequency types is a good way to compensate for the differences in wood by working on how to get the combination of pieces to work together harmoniously.

Alan Carruth's explanation of chaldni glitter patterns has changed the way my guitars sound when finished. I have always used tap tuning and still rate all of my wood subjectively (similar to what Kevin does) but by being able to visualize the focused pattern that the wood is resonating at by using glitter patterns helps me to know if what I am hearing is resulting in a more focused sound.

I only build classical guitars so for me building is much less about variations in thickness of materials as the range of woods used for a classical is much more limited. For a classical guitar it is all about good volume, a tone that is not predominately bass, treble or midrange, separation of notes per string and having a first string that sings. Voicing whether it be tap tuning or glitter patterns, it is all about being able to better understand the sound that is produced by the instrument as a whole and for each piece.

Just so you all can say that now you do know somebody. I have played a Cumpiano, well mostly just strummed it. There is in one on town that he built for Mario DaCosta but being that Mario owns it I will never see it. Bill explained that he is moving away from custom builds and is planning to just build what he wants and then offer them for sale. He does not do any extravagent work on his guitars, no inlays other than fret markers and sometimes not even them. He didn't even have a headstock logo on any of his guitars (8 or 10 of them) that I have seen. He does concentrate on paying attention to the details that make the guitars sound the way he wants them to. I can't honestly say I can remeber the sound properties of that guitar I played. I do remeber it felt quite nace and was very light.

As for Siminoff. I have read his book and have talked to him about his methods of tuning the pieces. I have strobe tuner that I bought through him and he is just about now to come out with a new book on using a tuner to test the frequencies of the parts. Ther is a misconception that he advocates that you "tune" every part to a particular frequency. He does not, if you did that then every guitar may sound just like the next (if it worked!). What he advocates is that you work towards making sure that each part and the then finished chamber all resonate at a frequency that falls in the A440Hz scale. He states that this is important because if you don't pay attenetion to this and the final chamber frequency is a few cents off of A440 then you get that "wobble" sound, just like when you are tuning using harmonics. This makes sence to me and is not so "out there" as most people think, IMHO. I too was underthe impression from his book that I should be looking for notes in each part of the instrument, until I talked to him. Anyway, he has promised me a copy of his new book as soon as he gets it from the publisher and that he will answer my questions on this method once I start to try it out, and I will. On another not, the frequecy of concernt pitch (right it is A440) tends to change over time. The 1920's Lloyd Loar mandos were appearantly built to C256 (C is presently 261.63hz, a full 1/4 tone higher) so Siminoff states that these mandos, played with newer instruments built to A440 will always sound a bit out of tune....probably OK for Bluegrass , well for my Bluegrass playin' anyways. Oh ya, ther is a group appearantly seaking to change concert pitch yet again, but I can't remeber what they are suggesting, or why . Memory like a steel trap I tell ya!

Shane

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Canada