tap tuning

[carleshicks]

I know this is a worn out subject, But I went to siminoff's web sight and he has a new article "What was Loar hearing?" That goes into depth on how The Loar era instruments Where tuned In the '20's. It talks about Tuning to A 431Hz as a reference as opposed to A440hz of today. It is a very interesting article That could spark some very exciting discusion on this board. So first off Is tap tuning the best way to achieve optimum tone and volume? Second would you tune to reference A 431 or 440?
And third what tool would Loar have used to tune The master model instuments In the 20's? I hope this turns into an insightive discusion that some of us new builders can learn from. Maybey Mr. Siminoff can even chime in.

[sunburst]

Sorry, but http://www.mandolincafe.net/iB_html/non-cgi/emoticons/sleepy.gif

Let me add:
After about 20 years of building mandolins, reading, talking, and studying about tap tuning, I'd rather be trying to build better mandolins and trying to learn how to make them sound better than spending my time trying to tune pieces of wood to arbitrarily selected pitches.

[carleshicks]

That is exactly what I want to know. I have no prior expierence building Mando's so tuning each piesce seems to make logical sense to achive good tone because it is measurable. but I don't know so I thought a deep discusion could save me from having to buy a $500 Strobe tuner. but I am curious how did Loar do it? The label says Each piece is tuned. Was It a marketing gimic Or did he do it And If he did what would he have used?

[sunburst]

I don't know what Lloyd did. It would be interesting to know.
I've suspected for years that the tuning stuff was mostly marketing.
I think weight and deflection are better gauges of top and back suitability than pitches. They too are measurable, and I suspect less susceptible to being "fooled" by variables of hardness, density, and so forth in different species of wood, different trees, etc.

Having learned a small amount of what is known about plate modes and the effects of bracing, I don't see where tap tuning is very useful to me. Gaining a "feel" for what a good piece of wood feels and sounds like while it is worked, through experience, can be valuable to a luthier, but personally, my early attempts at tuning pieces to specific pitches, and recording them, never exposed any correlation to the final sound of the mandolins.

[carleshicks]

Would that explain the noticable diference in tone from one loar to the next?

[sunburst]

I think there are more variables then I, or anyone else, know that can make one mandolin sound different than another.

[Stephanie Reiser]

I wonder which Antonio Stradivarius was tuning to?
Point being, I tend to wonder if that tuning is all that important.
I carve to thickness, and that is it.

[Chris Baird]

I read that Siminoff article and it brang my understanding of his point of view to a new all time low. From what I know of musical instrument acoustics that article makes little sense.

[Darren Kern]

Some guy I once knew had an opportunity to talk with a rock star guitarist once, and he asked the rock star all kinds of questions about his amps, setup, what pedals he used, etc etc etc. The rock star asked him "have you played 500 gigs yet?" Of course the guy said "Uh, no." The rock star answered "Then just plug in, and turn up the volume. Come back when you've played 500 gigs and we'll talk." I figured I'll worry about such things as tap tuning once I've built 500 mandolins http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[carleshicks]

I sense a lot of hostility towards Siminoff's method of tap tuning. I didn't meen to open a can of worms. I guess I was intriguid by the fact that it seems like a very cut and dry method for obtaining a desirable (Loar) tone. I know a lot of arch top guitar builders claim to tap tune to achieve a particular voice, even Lynn Dudenbodtel sayes He listens for a certain note when carving his plates. I am just curious what method I should use to obtain the classic mandolin sound I am looking for without building 500 bad mandolins to get there. I look foward to experimenting but I was just wondering if this was the method that Loar used.

[Jan Ellefsen]

Maybe it makes sense to tap tune in 431 when you tune the instrument to 440. At least you will not get an instrument that amplifies one or a few notes more than others.

[PaulD]

I sense a lot of hostility towards Siminoff's method of tap tuning. I didn't meen to open a can of worms. I guess I was intriguid by the fact that it seems like a very cut and dry method for obtaining a desirable (Loar) tone. I know a lot of arch top guitar builders claim to tap tune to achieve a particular voice, even Lynn Dudenbodtel sayes He listens for a certain note when carving his plates. I am just curious what method I should use to obtain the classic mandolin sound I am looking for without building 500 bad mandolins to get there. I look foward to experimenting but I was just wondering if this was the method that Loar used.
I suggest you only plan on building 10 or 20 bad mandos and make the rest of them good! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif Seriously, in following this thread I could tell that you were just looking for some direction. I bought Siminoff's concept of tap tuning when I first read his book, but the more I read the more I think there are other things that will get you farther faster. Keep in mind... I'm still trying to get my life in order to build my first instruments so I'm speaking from research rather than experience.

I suggest that you read more on "tap tuning" from other sources and it may help you get your bearings. Here is a writeup from Cumpiano (http://www.cumpiano.com/Home/Newsletters/Issues/newsletter10.html) that says "Tap-tuning" has been oversold." There used to be an interesting article called "Voicing the Steel String Guitar" by Dana Bourgeois kicking around the Web, but you may have to buy a back issue from GAL (http://www.luth.org) because I'm not seeing it now. Search folks' opinions in the archives here and on MIMF.com.

I think the general opinion is that Siminoff is using the term differently and at a different stage of building than most folks. I get the impression that very few builders actually try to tune the top to a specific note using a Stroboscope, but rather try to get it to "sound musical" as they shave braces and do final graduations. That might be an oversimplification.

That's not to say that Siminoff is lying, or doesn't get good results with his technique, or that he's getting kickbacks from Peterson for selling Stroboscopes. It just seems that most builders don't buy into Siminoff's theory and definition of tap tuning.

Frankly, as I read this stuff I'm more sold on deflection tuning, and it's something I can set up to do economically. I won't know for sure until I put tools to wood... my woodworking experience tells me experience is the better teacher. I'm sure I'll make some bad to mediocre instruments when I get started; I just don't plan on making 500 bad ones! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Paul Doubek

[Chris Baird]

I think that most builders listen for the tap quality when tapping on parts. Tap quality meaning clarity, sustain, and just an overall musical sound. Besides Siminoff's assertions I've never heard from any builder a system for tap tuning. It is either a secret or non-existant.
#My main problems with the Siminoff article are as follows:

#"Loar specified that the backboard of the F5 mandolins were to be tuned to C256, the treble tone bar to A#228, the bass bar to Ab203, and the air chamber to D143"

There is no way that these frequencies could ever be produced by a fully constructed mandolin. #An air chamber resonance of 143hz! I don't think so.

# "I placed Loar’s F5 in an instrument stand, set up the sweep frequency oscillator and speaker, and asked her to place her hand on the backboard, close her eyes, and nod when she felt it vibrate more than at any other time. I ran the sweep slowly, beginning at about 50Hz. As the sweep approached 250Hz, I saw her tip her head. When she nodded her head assertively, I stopped and asked her to open her eyes. The frequency counter was at exactly 256Hz! (While I was amazed that it was exactly 256Hz, the precise frequency for 4thoctave C when A=431Hz, I wasn’t surprised.) We did the test again, this time sweeping down from the higher frequencies. We got the same result, but missed it by 2Hz (which is still great)."

#The above example illustrates to me that Siminoff has only a limited grasp of vibrational modes and also that a completed instrument functions as a system where as you would feel the back vibrate at the A0 mode, which I would guess is what his wife is feeling at 256(although rather low from what I'd expect.) #
#The article is just full of holes and calls into question everything he ever wrote on the subject. I don't mean to come off as harsh or to mean any ill will toward Mr. Siminoff but I don't like it when someone aggresively propagates false physics for all the new builders to pick up.

Siminoff Article (http://72.14.203.104/search?q=cache:_xk-_CZ-SdcJ:www.siminoff.net/Media/download_Loar%2520hearing.pdf+what+was+loar+hearin g&hl=en&gl=us&ct=clnk&cd=1)

[testore]

I couldn't agree with John more.
Gary Vessel

[sunburst]

Well put, Chris.

I have no hostility toward Siminoff's methods of building, tap tuning, or anything else. Any builder can use whatever methods he/she wants, and many approaches can be successful.

The perceived hostility among builders is mostly frustration, IMHO, from struggling, in their early years, to understand tap tuning as put forth in the Siminoff book, struggling with the process, and ultimately dismissing it, but only after considerable time expenditure, only to have the subject keep coming up because so much has been written that leads the student to believe it is the one true way.

[ellisppi]

One way that you could possibly use tap tuning to some advantage is suppose hypothetically your free carved top taps where the fundamental seems to be somewhere around
B. After you add and carve the tone bars (which by the way were tuned to 332.8476hz @ 286.8477Hz respectively oh PLUEEEEEZE!) the top now taps sort of at C (bars stiffen so highr note) Then when you attach the top to the rims, it now taps at D (stiffer again). This would likely not be a desireable situation. D wolf note. You could use this knowledge to try to end up at C# or D# instead of D. This is not necessarily what I do, but I would be suprised if anyone is carving a top that is not going to tune somewhere around C to D# or so. Deflection is the key.

[Dave Cohen]

I did pretty thorough modal analysis on a '24 Loar back in Feb & March of 2004, and presented the result, along with those of several other vintage mandolins, at the ASA meeting in NYC in May, 2004. The lowest air mode frequency was 300 Hz (measured w/ the body immobilized), which is on the high side of typical for f-hole mandolins. The (0,0) modes were a doublet at 278 and 345 Hz, which is not at all untypical. The rest was very typical as well. Kinda makes you wonder what Siminoff was doing.

The compelling reason for not bothering with some kind of involved "free plate tuning" was provided independently by Schleske and Attwood in the mid '90s. In essence, they tried to follow the modal frequencies of "tuned" plates and untuned plates into assembled violins, and found that they couldn't do it. The body mode frequencies of the assembled violins were pretty much the same whether they were "tuned" or not.

Peter Coombe has posted before about the different frequencies for the different "tonebars", and I have posted on that several times as well. No matter where you tap on a plate, you are exciting its' same normal mode frequencies, unless you happen to strike it at the location of a node for a particular mode. In that case, the particular mode is weak or absent, but all of the rest of the modes are present as usual, and at their usual frequencies. I have tapped on the different bars numerous times, and I always hear the same note. Of late, I have been tapping some uncarved plates into an fft program on my pc. I have been carving plates in the last week or so. When I get 'em graduated and braced, I will tap them into the fft program and post the raw data in a new thread here (if can I remember!). I'm pretty darn confident that the frequencies will not be different.

[peter.coombe]

I am of the firm belief that tuning to specific frequences is a complete waste of time, whether you use tap tuning or any other method. #Think relative and you might make some headway. #Tap tuning is mostly useful to improve consistency, but you need to make a lot of mandolins before you get to that stage. #For those interested, read my article (http://www.petercoombe.com/jaamim7.html) published about a year ago.

[sunburst]

Dave, often, I can't hear, or detect with strobe tuner, any pitch difference between tone bars, but right now, I have a top with two distinct and easilly distinguishable notes. (C + 25 cents, and C# + 25 cents.) I didn't try to tune them, I just checked them and that's what they were. Cathy could easilly hear the difference over the phone.
What's going on there? Am I somehow exciting different modes to a higher degree with each bar?

[Darren Kern]

Tap tuning is mostly useful to improve consistency, but you need to make a lot of mandolins before you get to that stage. #
Peter, this is exactly what I was getting at with my post. I think newbies like me are better served spending their time learning how to carve to some decent specs, learning how to properly fit the tone bars, learning how to form a recurve, learning how to get a good neck angle, etc.

[arbarnhart]

One of my primary "e-mentors" tunes tops and backs, but he just makes sure they are different. He says he gets more wolf tones if they are the same. He mostly adjusts the braces to get the optimum sound, whatever that might be, and then checks to make sure the back is at least a note different. I am probably oversimplfying. But he also told me not to get hung up on it, especially with the first few.

[Dale Ludewig]

Dare I wade in here? This topic has been talked about many times before. And it should be talked about more, I think, as more people investigate this. I still agree with those that tune, if that's the word, by intuition. That may sound simplistic, but I think it is what most builders actually do, although if you measured their results afterwards, their tap tones might be very similar, whether to each of their own instruments, or all the good instruments. I frankly don't know because I haven't measured.

I think a primary question is "how does a new builder approach this? How does the builder know without a number of instruments behind him/her know if he/she is going to get good results?" I don't know the answer to that question. After a time of building, you can just hear it, hopefully. Then comes the more difficult- I have a good sound, but I want "this". How do I get that? I think that is also more experience and intuition and occasionally a failure. More reason to string up in the white. Maybe before any binding goes on, to lessen the load. I certainly have no answer, nor do I claim to know how to make the best sounding mandolins. That is extremely subjective.

Gotta go make supper. Hope I don't burn pork chops while I think about this....... http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[Dave Cohen]

John, just speculation here, but it may be that one of your "tone bars" passes through a node for one of the lowest free plate modes. It is not likely that all of the tone bar is coincident with the node, so you may get a different result if you tap at a different location on the "tone bar". Try tapping the braces at different locations along their lengths. The Fletcher & Rossing text has a good discussion of rectangular free plate modes, with some pictures of Chladni patterns, on pp 81-83. That will give you an idea of where the nodes could be.

[sunburst]

OK.
I already tried tapping up and down the length of the bars, but I haven't looked at the suggested paper.
Interestingly, the one I mentioned is an F, and the A that I'm building along with it has bars with notes of C + 25, and C# + 15. Not as distinct, but still audible. Only 10 cents difference on one bar despite one being a sitka top and the other being a red spruce top; one being F and the other A.

These are both glued to the rim, BTW. Does that still make them free plates?

[Chris Baird]

I've often found that I can get a differentiation between tonebars when the top is glued to the rim but not as a free plate.

[carleshicks]

This discusion is going exactly where I hoped it would. Peter Coombe and Paul D. Those where great articles Cumpiano does a very good job or debunking Tap Tuning as a quick easy method of achieving consistunt tone. Peter your article was exactly what I was looking for.

[Dennis Russell]

Hello: I am a new builder,, been at it since 1994, the first instrument I built was a f5 mandolin in 1994, I used the Siminoff book for instructions. I didnt have a strob-o- tuner as he was referring to it. I took the almost finished mandolin to a luthier freind in the other side of town. I had finished the mandolin where the onlything need left was putting on the back plate. This luthier had a strobtuner and asked me why do you need this thing tuned that way, like he was mystified that I would attempt such a foolish thing. I left the book with him and came back several days later. he said I shaved the tone bars down a bit but no significant change in the tone, he said glue it up and put the strings on and play it.
He said he only uses the strobe tuner to accurately tune guitars and other string instruments, said in all his years as a luthier he never heard of any such thing. He said I am not a builder , I just do repairs and this is all new to me, he said he knows violin makers that can tap the wood and listen to it and determine if this resonates correctly or will be a good piece of tone wood. He also said this is a lost art tapping the wood and listening, he said I could never do that, something that has to be practiced.
Since then I have built several mandolins and several guitars and two violins, but never used tap tuning except the last one I built. I bought a Peterson strobetuner, but the instructions were vague on how to use it, and there isnt anyone around this one horse town that knows how to operate one except the music department at the local high schoool. They use it on their wind instruments when tunning up for band practice, but not on string instruments. There was a old timer that I befreinded a few years back that gave me a nice peice of quilted maple to use for a violin or mandolin. I told him about two years ago about this Strobetuner I bought to tune sound plates, he looked at me in wonderment and opened his mouth and yelled like a giant fog horn, some awful cuss words I never heard before.. young fella he said you dont know squat about tap tunning and you had better leave it alone to the experts, and throw that electronic #### you have in the garbage. I tried to show him this siminoff book, he said interesting with a smile but he said let me take it back with me to my summeer home in Washington and I will hang it in the privy to use for toilet paper. he comes from the old mould, he picks wood up taps it with his small pocket knife and holds it close to his ear on either side and listens,, he said with a smile you have to learn this way, trusted and true, I could never learn how they do that, he said listen to it if it sounds different at different areas on the wood ,, he went into a long disertation of how to. Well anyways I have this Strobotuner just sitting here collecting dust going to sell it some day.
This old fellow passed away last year, he was 93 years old used to work in a saw mill, he had access to a lot of good wood used to bring me some when he came here for the winter, even brought some Eulin wood for making violin bows, He manufactured over 48 violins in his life time, very beautiful instruments, had a sweet sound to them, he played his instruments sitting down with vilon on his lap where he could look down on it and running his bow across the the strings. He was very meticulate about building, he will be sorely missed. Dennis In Yuma Arizona

[arbarnhart]

Rather than just posting my (probably off a bit) summary, here is an excerpt of the email I got from a stringed instrument builder when I was looking for tips on carving braces on the flat top:

If you look around at some of the guitar sites and see all the bracing they put
under some of the top, the initial impression is that all that wood should kill
the tone.
A few years back I had a set of spruce boards for a Mt. Dulcimer. The wood
was very light weight and weak feeling, just gave the impression it had been cut
from an old standing dead tree. #I cut out a section for a stick, two piece top.
I tapped on the wood and it was like tapping on a piece of corrugated card board.
flat, dull no ring at all. Considered throwing it away, but decided to give it a try on
a more or less experimental instrument. #Joined the two bookmatched halves, it
had a little tone but dull, #added the confidence strip over the seam, now it had
a little more tone. #Added the "V" type bracing I use for my sticks. the top now
came alive. I shaped the ends and it improved more, #I carved the braces to a
sharp top edge, (removed about 1/3 total bulk of braces) it now had a very nice
ring. I went on to build a nice instrument out of it.

There is a bit of an art form, #and seat of the pants feel for getting the desired
tone from a top. I have over tuned tops past the peak of "best" sound, and have
popped off braces and put on new ones for a fresh start, (not my favorite thing
to do) #My main objective is to bring the top to a good ring and insure it is not
the same tone as the case. I go for at least #1 1/2 note difference. This seems
to lessen the chance of getting wolf tones and dead spots that occur when
the vibration of the box tries to kill the vibration of the string.

Like I said I do this mostly by the seat of my pants, but when building a custom
instrument I use a audio spectrum analyzer to obtain the frequencies of top and
bottom.

[Dave Cohen]

Dale's post and Dennis's post highlight what for me is an important issue. It is not the physics of the mandolin, but rather the perception of what is involved in making a mandolin. Dennis's beloved crafstman was the stereotype of craftsmen, embodying one of the keywords used by Dale. That word is intuition. You are supposed to build numerous instruments for numerous years, and the intuition will gradually, gloriously, and almost magically come to you. And when you have it, you will somehow know what to do in each step of instrument making. Wayne Henderson was reputed to have said something to the effect that to make a mandolin, you just carve away everything that isn't a mandolin. Sounds cute, but it's actually pretty glib, albeit common among "intuitive" makers. Also, I think that it implies that some fortunate few, "have it", while most others don't, and further, they most likely won't be able to aquire "it", whatever it is.

Predictably, I take quite a different view. I think that if you are doing some activity that results in a tangible product, you should ultimately be able to come up with a tangible explanation of whatever it is that you are doing. You may very well call it "intuition", but that doesn't explain to others what "it" is. Intuition is not unique to artists, artisans, poets, & other practitioners of so-called "right-brained" activities. Scientists and mathematicians use intuition a lot, and they readily admit to it. Ultimately, though, they have to describe the process in order for their works to get through the peer review process. So what exactly is intuition? It is not too controversial to say that intuition is actually the sum of experience. I was talking about that to some undergraduates once, and a girl boldly stated that the first time she sat behind the wheel of a car, she was able to drive, and that she knew how to do it intuitively. I countered with "But, had you been watching other people drive before that moment?" She had to admit that yes, she had been watching. Here is another example. When I was an undergraduate at UC Berkeley in the mid-1960's, I was struggling with a particular DE problem for several days, staying up until the wee hours banging my head against it. My father was supportive, noting that I was "hanging on like grim death" and would surely solve the problem eventually. The next Saturday morning, I woke up and knew instantly how to solve the problem. What had enabled it? The pieces had simply come into focus together, and I saw their interrelationship in that waking moment. Intuitive types would call it intuition, but in the analytical disciplines, we ultimately describe it as the "motivation" for pursuing a sequence of steps in solving a problem. Once we put all of the steps together, we can describe the whole process analytically, and the motivation is the recognition that leads us from one step to the next.

My ultimate p[oint is that the "intuitive" process can be described such that it can be repeated by others, regardless of whether it is described in artistic terms or analytical terms. Iirc, someone mentioned the Dana Bourgeous article on tap tuning. That was an excellent example of describing an "intuitive" process such that others could follow and ultimately repeat the process. But if you just chalk your process up to the single word "intuition", you are condemning your readers to a state of confusion until such time as the "intuition" somehow comes to them, if it ever does.

[sunburst]

Well put Dave.
I see nothing wrong with building with "intuition", or calling it "intuition", but I think the word gets used as a "cop out" for not being able to easilly explain ones process, learned, as you say, from the sum of experience.

[carleshicks]

were do I find the Dana Bourgeous article.

[PaulD]

Dave, In defense of Roger Siminoff's publications, I think he is attempting to "demystify" and "quantify" a process that would be described by some as "intuitive" or experience based. In other words, I think it's an attempt to do exactly what you say he should be doing. I think he's very convinced that he's on the right track, and his "What Did Loar Hear" seems like an attempt to validate what he's already been preaching. Granted, having someone close their eyes and feel the instrument vibrate is not as objective as measuring the vibration at various frequencies, and a sample size of one instrument and two tests is not statistically significant. I'm not qualified to say that he's wrong and I do believe he's well intentioned. All I know is that in my quest to gather information you have all convinced me that his process and numbers are probably skewed and that there are measures that are more likely to lead me to building a "better" instrument (I know... "better" is subjective! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif ). I'm very grateful to all of you who are willing to share their experience and to Al Gore for inventing the Internet so we have a place to share this information! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif

Edit: Carles, you were typing while I was. As I stated in my previous post, the Dana B. article used to be out on the 'Net, but I couldn't find it yesterday. All the links appear to be broken. I believe it's published in one of the GAL back issues or one of the Big Red Books that they sell (www.luth.org). I have a copy I printed a couple years ago stashed in one of my binders. If I have time to find it I'll p-mail it to you.

Paul Doubek

[carleshicks]

Thanks Paul D. I was just wondering what isue of GAL it was in. I will do a search and see what I come up with.

This discusion is doing exactly what i was hoping it would do.
does anyone know what proccess Lloyd Loar used To "tune" the master models. I know it was stated that it was probably just hype but there is something about those instruments that just stand out. Do you think that he just tapped and listened and went on intuition or did he have some measurable way of tuning the "top, back, tone bars, and air chamber".

[Dale Ludewig]

Dave, I agree that that was well put. Better than I said it. And you're right- that what I referred to as "intuition" is largely experience. And I would suppose that the experience of those that have come before, such as Loar, have given us our basic dimensions and graduations. I guess that's where a first time builder starts- it's where I did. I do still think that there are some aspects to the final graduations and such that contribute to the sound that are difficult to quantify. I certainly did not mean to imply that "some have it and some don't". If that is what you thought I meant or anyone else did, then I regret using the words I did.

[Dave Cohen]

Dale, I wasn't reacting to anything in your post that I saw as negative or wrong; just venting about a long standing issue. Your post just seemed to remind me of the issue somehow.

Paul D., I have posted numerous times before that I don't want to sound like I am being too hard on Siminoff. After all, he has attempted to use some measurement. It is just that at times, he says some stuff that is SO fictitious with SUCH certainty.

Luthiers. like scientists, are empiricists. They try things, and when they find something that works, they hold on to it. When they find something doesn't work, they discard it. And they are pretty good at being empiricists, or at least good luthiers are good at being empiricists. The problems I have seen often come when they attempt to explain their observations without bothering to check on whether their explanations are in violation of Newton, Hamilton, LaGrange, etc. That isn't to say that something can't be wrong w/ classical physics, but if you do find something that seems to violate long established laws, you really should do your homework and have some defensible reasons and mechanisms for the apparent violation.

There is no rule that says a luthier must come up with his/her own explanation for everything. Bob Benedetto, in his archtop book, reminded us that if we don't know something, we shouldn't make up something or try to come up with some science fiction. There is absolutely no harm in telling a customer that you don't know something. In fact, I think that customers appreciate the honesty and candor.

[otterly2k]

speaking as a customer, I'll support that statement.
I'd rather have someone tell me "I don't know why it works, it just does" than have them make up some pseudo-scientific or magical or nonsensical answer that is intended to impress me. If that person has sufficient experience to back up the "it just does" statement...I'm ok with that.

[PaulD]

Dave, I do agree with your assessment, and when someone publishes some "fact" it's always a good thing when they back up their conclusions by citing sources, studies, test methodologies... something. If you read the forward (or maybe it's the back cover) of Siminoff's mando building book you assume he is a recognized authority, but then you learn that he's knowledgable but his "facts" should be taken with a grain of salt. As I said, I think his intentions are good but he could do some work on his credibility.

As far as being honest when you don't know something, or stating that "this is a guess", or coming out and admitting when you find out you were wrong all go a long way toward building credibility. It doesn't matter if it's luthery or politics or computer network engineering.

This discussion reminds me of a Nagyvary thread I started some time back. I had read his "theories" years ago but then hadn't heard anything about him or his theories for 15 or 20 years. I brought up the idea of soaking wood in salt water and generated a firestorm of folks saying the guy's full of ____! After doing some more research I can see where he's spouting his "discoveries" as factual but hasn't been able to back it up with actual results. He was recently in town lecturing and the local paper did a good job of recognizing that not most luthiers don't take him seriously. In fact they closed with a statement from a respected violinist that played one of his fiddles during the lecture; she said essentially that it was nice but nothing spectacular.

pd

[sunburst]

There is absolutely no harm in telling a customer that you don't know something. In fact, I think that customers appreciate the honesty and candor.
I got a funny look about an hour ago. A customer was looking at his mandolin-in-progress. The top is glued to the rim, the neck and back arent glued on yet. He looked at the "tone bars" and said "what do they do?".
I thought of all the stuff that I know about them, some of the things that Dave has observed in his experiments,...and said "I don't know".

[Jim Rowland]

I think,as has been implied,that we ought to give Roger S. credit for making a solid contribution to the mandolin world. He wrote and published a fairly well illustrated guide which gave many the confidence to dive into a carved mandolin project. While a number of "facts" may be questioned,the value of his book in that regard cannot. Irving Sloane was another such author,and I believe that he made a major contribution to guitar luthiery,even though some of ideas he presented as fact are conjecture or lore. Getting something together that looks like an F 5 is quite an accomplishment,that little fellow being one of the toughest instruments to build.
Interesting account of your experience dealing with a tough problem,Dave. I have had
a few similar experiences which I chalked up to "Gestalt",which implies a product more than the sum of its parts. Your explanation is more logical.
Jim

[Bill Snyder]

does anyone know what proccess Lloyd Loar used To "tune" the master models.... Do you think that he just tapped and listened and went on intuition or did he have some measurable way of tuning the "top, back, tone bars, and air chamber".
No. I doubt that he tap tuned anything, He was management. He had luthiers working for him. I think he had final approval of the Master Models, but I don't think he did much of the hands on work on the mandolins.

[Bill Halsey]

Phenominal thread - I love this stuff...
But, we're not looking beyond Lloyd here; i.e., what about Hermann von Helmholtz?

[Michael Lewis]

http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif

[peter.coombe]

All I can add to this discussion is
(1) Any one here who is tapping plates or tonebars should read my article. Then at least you will understand (hopefully) what you are hearing because then you can see what the eigenmode patterns (what you hear when you tap) look like.
(2) One day I will get around to publishing an article about eigenmodes in mandolins with the ribs attached and how they relate to free plates.
(3) I am very well aware of the lack of evidence of any correlation between free plate eigenmodes and the modes of a competed violin. In fact the papers sited by Dave are also mentioned in my article. However, I have done my own, addmittedly crude, experiments that have utterly convinced me that is it worth measuring tap tones (or Chladni patterns) in free plates. I have made 2 pairs of mandolins (one pair of ovel hole mandolins, one pair of F hole mandolins) from identical woods that have been tuned as close to identical as I can manage. Result - they sound near enough to identical. My wife could not pick them if she can't see them. I have difficulty telling them apart when playing, and have been caught out at least once with the wrong mandolin in my hands. I have also made one pair of mandolins from identical woods, but tuned completely differently. Result was they sound utterly completely different. No problem at all in picking which one was which, and everyone I showed these instrunents picked the same one as the best sounding instrument. This type of experiment is incredibly time consuming, and I really need to make more pairs of mandolins to prove repeatability, but it utterly convinced me of the worth of using the technique to improve consistency. One day I will get around to publishing this experiment as well.

Unfortunately I really don't want to make any more like that mandolin that nobody liked in the comparison! It was greatly praised when on it's own, so it was still a good sounding mandolin, but the story changed when I pulled out the "twin".

[sunburst]

I, too, have built twin mandolins. Same wood for every part, cut as closely as possible from the stock, carved to the same "numbers", tuned as closely as I could to the same notes, even stained and finished together and strung up on the same day.
Mine sounded identical too.
I have since done the "experiment", but changed one variable. One top was red spruce and the other was sitka. Otherwise the two were again identical. That time, they sounded very slightly different. I took them to a festival and had lots of players play the two, without telling them what the difference was, and found a split in which was the preferred one. Slightly more people preferred the one with the sitka top.

I've thought for years that I might continue the "experiment", changing one variable at a time, but it seems that I'm building to order these days, and don't know when I'll be able to spec two more mnandolins.

[Dave Cohen]

John, it would be a more convincing experiment if you used one Sitka plate and one Adirondak plate, tuned them the same, built the instruments, then made the comparison. Of course, it would also be interesting to see what the body mode frequencies of your completed "identical" mandolins are. The lower body mode frequencies of an assembled instrument can actually be gotten from accelerance spectra, obviating the need for holography.

[sunburst]

Dave, in fact the sitka and red spruce were tuned the same, throughout the process, from free plates to assembled instruments. They actually ended up tuned "samer" than the earlier twins, which were a few cents different at some stages.

I don't know where the twins are these days. I'd never heard of accelerance spectra when I made them.

[Dale Ludewig]

I just got back from a weekend bluegrass festival. Brought a laptop but never turned it on. Too much fun or too tired. Then had a music job this afternoon. In any case, this is the first I've been back to this thread since I last posted.

Dave, thanks.

I haven't had a chance to read Peter's writings. Is the accelerance spectra mentioned in there, of if not, where? I've never heard of it.

This is a good thread. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif