Official Luthiers Forum!

Yeah, Hesh, but your post was at 16:46, and Dave's was at 16:45. Naaa, naa, na naaa, naa!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

DAVE!!!! Is this true??????

Kevin: There is no need to refrain from naming the person whose opinions or guitars you are critiquing. Many internet fora seem obsessed with a "no negativity" policy which IMO is based on a lack of understanding of the difference between criticizing a person and criticizing an opinion or an object (which in turn, I think, originated from a period in elementary education which stressed building self-esteem over building excellence, but that's probably a story for another forum). This unfortunately leads to a kind of bland happy-face pablum in which every post and every object discussed is great, and no one is able to learn anything or improve her work or change a faulty opinion. If you are indeed talking about Bill Cumpiano, I'd like to know what you think about the sound of his guitars. I doubt that his ego is so fragile that he would be offended by an honest negative review.

Speaking of names, I'd like to know whose opinions and experiences I'm reading about here. So if you use a handle (e.g., "Sharp Custom"), could you sign your name so we know who you are?

Bruce, I'm trying as hard as I can to stay in denial about taxes, and your post has disturbed my fragile mental balance. I'm planning to get back in denial and build guitars today. It's February for Pete's sake, and you guys who do your taxes early and then get smug about it should at least have the decency to wait until March.

"Dana tries to avoid ghost or false harmonics for the plates, meaning getting clear notes at different places, and intuitively that makes a lot of sense to me."

Laurent, I don't know what you mean by ghost or false harmonics. Please explain.

I have a hypothesis about intuitive voicing. It's that people will voice a guitar so that it's voice resembles their own. More field work is needed to confirm or refute this hypothesis.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Guys....I love these very informative debates..........But JJs little dog is freakin' me out...Hope that little sucker is not as mean as he looks.....

Larry - I looked at that avatar of JJ's many times before I realized it wasn't a cat...

(SORRY JJ!)

Anywho...someone asked to see the original post that this discussion originated from, so that context could be preserved and all opinions could be seen...

here it is:

http://www.luthierforum.com/index.php?showtopic=3576

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Mitch

[quote="Howard Klepper"I have a hypothesis about intuitive voicing. It's that people will voice a guitar so that it's voice resembles their own. More field work is needed to confirm or refute this hypothesis.[/quote]

I am in Deep Doody then!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

you have heard my guitars.... do they have a southern accent??

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Reguards,

Ken H

That avatar was given to me by someone who himself is a cross between a junkyard dog and Lassie. They're both really loveable little fuzzballs whose barks are bigger than their bites!

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JJ
Napa, CA
http://www.DonohueGuitars.com

[quote="Howard Klepper"]
Speaking of names, I'd like to know whose opinions and experiences I'm reading about here. So if you use a handle (e.g., "Sharp Custom"), could you sign your name so we know who you are? quote]

My name is DON!! Didn't even think about signing my name it used to be there on the old forum. So here it is for anyone who cares.

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Don Sharp
Got Brazilian?
http://www.sharpguitars.com

Cumpiano has written about his "thicknessing criteria" over on Luthierforum. I hope quoting from the thread in question can be considered "fair use" of the material and that is is OK to post it here, if not feel free to remove it (the text from Luthierforum is in italics).

The question he got was:

Do you use a specific thickness for tops, backs, and sides, or do your thicknesses depend on the wood species used. I've been reading some conflicting
information on this topic and would love to hear your thoughts.


To which he answered:

I select all my soundboards for a certain familiar stiffness and springiness, and then reduce them to a specific thickness according to dimensions that have given me good results in the past. These dimension "standards" vary only regarding to the instrument size and the wood specie in question, not according the "tap tones" or "feel" of a particular piece as its being reduced--as some builders claim to do.

Admittedly, this is different claim from what I wrote in my book, which said that I tapped the top as I thinned it, and stopped at a certain ring. That was in 1985 when i wrote the book. Not 20 years later, because my approach has evolved since then.

As to the sides, they are strictly thicknessed in consideration with the bending requirements of the specie involved. And the back is thicknessed, again, according to species and soundbox size, the dimensions that have produced the best results in the past.

Early instrument luthiers call the thickness specs for the plates of their instruments the "scantlings". My scantlings follow.

Summing up, for 16-inch steel string guitars:
Tops: .115 to .120
Backs, hard: .095 to .110
Backs, soft: ..110 to .115

15 to 15.5-inch steel string guitars:
Tops: .100 to .115
Backs, hard: .095 to .100
Backs, soft: .100 to .110

14 to 14.5 steel string guitars
Tops: .095 to .100
Backs, hard: .090 to .095
Backs, soft: .095 to .100

Sides for all guitars (dictated primarily by bending requirements):
hard: .080 to .085 (extremely hard, like cocobolo,etc.: .078)
soft: .085 to .090
(Thorough wetting only, no long soaking or boiling.)

Classic:
Thicknesses are all over the place, depending on whose scheme I'm following. Some schemes have heavy scantlings, some have feather-light scantlings.
But an average would be:

Tops: .080 to .095
Backs, hard. 085 to .090
Backs, soft, .090 to .095



Here’s my take on it:

Of course Cumpiano has gained a whole lot of experience over the years, and the methods he uses now are based on that experience. I’m sure they are quite refined, even though it sounds pretty straight forward when he says: “I select all my soundboards for a certain familiar stiffness and springiness, and then reduce them to a specific thickness according to dimensions that have given me good results in the past” . That sounds easy enough, but what if you have not made those instruments in the past?

As a hobby builder making just a few instruments per year there is no way I believe I can single out the sonic contribution of every little detail in each one; for starters I will usually change several things from one instrument to the next so who knows what made the difference? As one reference point (or "constant" I guess) I use a similar, traditional X-brace layout on all my guitars, but I build with many different woods and body shapes, and I adjust the bracing position according to bridge location, and the braces' dimensions and profiles according to the size of the box, and I graduate the tops. Already there are enough differences that the picture of the effects of each one of them is quite obscure. Also added to the mix is the fact that each piece of wood is different... I do keep notes of everything I can though; all the thicknesses, brace dimensions and positions, the perceived stiffness of all the parts (though no hard numbers, I just go by feel), and of course wood species, characteristics, grain, density… Oh yeah, I also weigh some parts, I have a little nifty gram scale. I also note my impressions of how the instrument sounds once finished. Hopefully in the long run I can make some sense of it all and gain a deeper understanding of what is going on, now I am mostly guessing, albeit slightly more informed with each instrument.

Building the way I do, after a while you do get a general sense of the effect that each of the constructions elements has on the overall sound, but it's hard to pinpoint exactly what does what. As has been said, the easiest person to fool is yourself… Anyways, for me this is a more fun way of building, I like to try a bit of everything and I'm too lazy for research other than actually building them and keeping records and learning as I go!

I also learn a lot from inspecting and playing as many good instruments as I can get my hands on, and working on many different types of guitars. Simply seeing how they are made and listening to how they sound is a pretty good education too.

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Rian Gitar og Mandolin

Good info, Arnt! This seems to clarify and explain his position.

Whether perceptions are derived through the ears (tone) or the hand (stiffness) he's making judgements on what he selects for and feels that the results will be predictable. And presumably, his customers agree with the results of his methods. As Howard mentioned...it all comes down to how his guitars sound.

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JJ
Napa, CA
http://www.DonohueGuitars.com

Yes, Arnt, great info.

scantlings -- used in boatbuilding too.

Cumpiano makes a distinction between tapping a top to get information while voicing and tuning to a specific frequency. In his newsletters he does talk about how he uses de-tuning, to get an indistinct tone from tapping, as opposed to a bell-like tone with a certain frequency. So, in our vernacular, he does voice, but doesn't tune.

http://www.cumpiano.com/Home/Newsletters/Issues/newsletter16.html

To qualify, though, this article is dated 1999.

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now known around here as Pat Foster
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http://www.patfosterguitars.com

As a complete newbie, I recently studyied all the writings (and watched all the DVD's) that I could find on the subject of tap tuning. As a result, I felt that I did indeed need to introduce a scientific tap tuning method into my building process in order to acheive guitar greatness. I purchased a Peterson 490 strobe tuner, a Roland Boss compressor/sustain unit, and various hard/soft felt hammers and set to it.

Using a simple mic -> compressor -> strobe tuner setup, I found I couldn't successfully measure the tap tone frequencies of the individual tone bars, so I investigated further. My Tectronix digital sampling oscilloscope with its built-in fast fourier transform (FFT) math function showed that the main (coupled system) ring tone completely swamps any individual brace's tone. I experimented with different microphones (cardiod vs. super directional, magnetic vs. condenser, etc.), pre-amps (to get the signal levels "just right"), and filters (high-pass, band-pass, variable Q, etc.) ahead of the strobe tuner. With careful setup, I found I was just about able to "tune-in" and isolate the individual tone bar frequencies electronically, however, on the strobe tuner, the measured tap frequencies produced by the individual tone bars varied too much to yeild any information that might be useful for brace shaping. The tap tone frequency seemed to depend on what I tapped with (how hard the hammer was), where I tapped the tone bars along their length/width, and how hard I tapped. Measuring the main coupled system tap tone frequency was easy and repeatable, so may be a useful metric - I've still not decided about that yet.

My conclusions:

1. Based on my admittedly limited experience, but fairly thorough scientific experiments and measurements over the past few weeks, I fail to see or understand how anyone can claim they can successfully isolate the individual tone bar tap tone frequencies accurately enough to provide any useful brace tuning information. Yet, I remain open to being shown the proof - just because I couldn't make it happen doesn't mean it doesn't work for someone else....

2. Tap tone tuning of individual tone bars is not gong to be a useful technique for me.

3. Measuring the fundamental tap tone frequency of the completed assembly (coupled system) may provide useful tuning information.

Regards,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Hesh:
Actually I am at least as concerned with structural issues than with tone production. Seems the second follows naturally the first, if everything falls into place, which it should. In other words I try to build the best sounding / non-self-destroying / long-lasting guitar I can.

Sam:
Personally I had to touch-up the top braces on a built guitar only once. It was a pain in the arse to get in there with a thumb plane and sandpaper. I am not even sure it even achieved anything: I will never know if the guitar sounded better after a while because of the extra-shaving, or because it settled in and was played. Better to learn how to properly "voice" a guitar with the free plates IMHO. I also revoiced a couple of Martins (from the 70's) with the back off (it needed to come off), which was easier than through the soundhole, but still not as good as with a free top.

Ken:
Your comment about burning guitars made me feel so good… I burned 4 so far, they sounded great though, but… humm… self-destroyed, sort of, each in a very personal way or I wasn't happy with the workmanship. Made me feel terrible though and some of my friends still think I am insane. Makes great kindling though.

Howard:
Perhaps my vernacular needs much refining… By ghost notes or false harmonics I mean wobbly tones, when you hear a not really defined note and those "out of tune" vibrations at the end of the sound. Not unlike playing two strings out of tune by a few cents. I know Dana wants to hear clear notes. So do I. I can't tell you what it achieves because that's the way I've always done it, even before working at Pantheon, so…
BTW I totally agree with you concerning disagreements. It totally OK to disagree, even educating. That's how we are introduced to foreign ideas, and to my mind that's the purpose of those forums. How do the other guys do things? What irks me though is gratuitous rudeness and phoney manly behavior. Unfortunately the anonymity of the internet allows plenty of that.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Howard,

It was obviously Bill Cumpiano whose statement I quoted. I've read his writings
as I have the writings of lot of other authors/builders whose approaches and opinions
I disagree with in some areas.

You cover a lot of ground in a single post. Regardless of forum rules or protocol,
I usually don't say negative about anyone or their guitars, but I can certainly offer
an honest opinion of the guitars I've played.

They sounded good, but nothing stuck with me to make the experience stand
out....which surprised me a little since I had just finished reading the Tradition &
Technology work that he had coauthored with John Natelson. I was still working at
Martin Guitar when they came into the North Street facility in the hands of a player
from Boston area while attending the ASIS Symposium in nearby Easton that year. I
guess I was expecting the kind of tone that we all expect when we get our first listen
to guitars built by people who have had a deep impact on the entire industry. I've had
similar experiences with guitars from other builders who are touted as the very best
in the world by the popular indstry specific publications, so its neither here or there
what I think.

To best describe their tone specifically, though, I'd have to say that they struck
me as being more dominated by the fundamental and pretty dry. They lacked the
kind of harmonic complexity that we're used to experiencing when we play many of
the guitars being built today in small and solo shops. Maybe they weren't the norm
in what is representative of Bill's work.

Nothing bad about their tone, but nothing that made me want to own one either.
I was just about to embark on my journey to start my own business as a full time
builder and it actually boosted my confidence a little and gave me one of my more
memorable comparative moments.

On the other hand, that same player had with him a Santa Cruz and a McCollum
that just blew me away and have been standards for me since. He had two or three
other guitars and I couldn't even tell you who built them....so the impression they
made on me is obvious, too.

It's great to read as much literature as we can on our trade, but it's enlightening
to actually get to see guitars built by the authors as we choose who our influences
will be. That day, I picked two guys whose quality I've shot for ever since....Lance
McCollum and Richard Hoover.

Regards,
Kevin Gallagher/Omega Guitars

I think Chladni patterns, tapping, and bending/flexing are all ways of picking up the same information. They're all measuring vibration/stiffness/density characteristics of an object and those three are all connected (given two of them, the third will tend to fall in a certain range). The Chladni patterns, a deflection test, and a scale to weigh things sure make it easier to keep records that correlate well, but I could get an approximation of all readings (relative to my sensitivity) with just my hands and ears.

I learned from Al, and I've played some of his guitars. I buy his method partly because he presented it to me in a very scientific 'here's what's physically happening, here's what the data definitely tells us, and here's what we hope the data can tell us' way, and partly because the instruments of his I played sounded great and the one I built with him sound -exactly- like I'd asked (and he guided me toward that end with voicing it).

I also believe that construction quality is a huge and rarely spoken of determinant of guitar quality. Think about how small the construction differences between certain brands of automobiles must be, given that they both work at all, and then notice how certain cars are much, much more reliable than others. I think we sort of assume all professional builders have the same amount of woodworking chops, but I think the difference between a good, great, and phenomenal set of hands makes a difference.

(And I think tuning individual braces is silly, though I think the onus is to put forth a good argument for doing it rather than for me to waste breath explaining why there likely isn't one)

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I know that this is an ongoing debate that it will go on for ever.
All I want to do is share an experience instead of debating.
I built a guitar with a fat neck. I strung it up and it sounded ok. It wasn’t what I would have liked but “ok”. I decided to thin the neck down so it would be more comfortable for me and as I did the guitar started to get more low end. By the time I finished, it lost all of it brightness and gained allot of bottom end. What I have learned is that every aspect of the guitar has an affect on the overall sound. I have no doubt in my mind that guitars have to be built as a “whole” in regards to the voice of the instrument. Neck thinning had a vary dramatic affect.

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Rich S

"The inconvenience of poor quality will linger long after the thrill of a bargain has been forgotten"

Good discussion. I doubt there will be a definitive answer as somebody will always come up with an exception. Science or perhaps better termed, technology has been trying to explain and reproduce intstrument sound by trying to put the subjective into objective terms. Put a dozen experts in a room and have them listen to a series of guitars and you will get 12 opinions on which sounds best and why. Kind of like wine tasting. Actually like winemaking too, now that I think about it. I do believe there are those builders who can "feel" how their work is going to affect the final product. That touch is a gift. Alas, I am not one of those. My building history, short as it may be has been to try and make the subsequent guitar lighter braced than the one prior. I think I'll go until one collapses and then back off a bit and call that "my tone".
Keep up the discussion. It is fascinating.

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Greg
http://garibaldiinstruments.com/

Greg. I think that's a good approach. The whole idea of tuning is very subjective. Whatever sounds good to the builder is the right sound for their instruments. There's no right or wrong here. It's simply a matter of what sounds and works best for you. I think that's what defines a particular instrument's or luthier's sound. There's a lot of science behind how a guitar produces a noise but in the end that stuff doesn't matter as long as you're happy with the results.

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Don Sharp
Got Brazilian?
http://www.sharpguitars.com

Actually you'd be surprised how people can develop a consensus. The differences between excellent instruments are very subtle, but generally people tend to agree on which one sounds the "best", or has this tiny little something "more".

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

laurent,
I agree. Even though a group of experienced people with discerning ears may come up
with different things about each guitar in a batch of test subjects that make them unique
or special, it's been amazing to me on several occasions to see such a group actually pick
the same guitar as being the one they consider to be the "best" of the bunch.

Regards,
Kevin Gallagher/Omega Guitars