Can you tell how good a ukulele is in part by tapping on it?

I have a very nice ukulele that I am in process of reviewing for my YouTube channel...the Flight Spirit Concert. It is a stunning ukulele in just about every way, and the closest ukuleles that I own to it are KoAlohas...in particular an Acacia concert Opio and a full-fledged Koa model from 2004.

I don't know what it is about the Koa model...certainly age has something to do with it...but its sound is transcendent.

The acacia is pretty wonderful, too...but it lacks something that the Koa has.

I also have a solid Acacia Bruce Wei that is still in great condition after a couple of years (no horror stories) with a smaller body and overall less sound. It is pretty and has a pretty tone, but it doesn't compete with the KoAloha or the Flight.

What i'm noticing is that the KoAlohas have a much bigger sound with a longer sustain than the Flight Spirit. The Spirit has recently been reworked to have a thinner top and more delicate bracing. The KoAlohas mainly have the unibrace. I realize that KoAlohas are cannons and that not everyone likes their sound, either. But I have to admit...I'm pretty partial to the sound of a KoAloha.

But what I found on accident today is that the KoAlohas (I also have a spruce/acacia concert Opio), when tap, all seem to have the same pitches on the tops and on the back. i haven't tested the actual frequency yet...I want to get some feedback before doing so. The Flight creates a higher frequency when tapped, and the Bruce Wei even higher yet.

I seem to remember that Kamaka hires blind workers to sort wood, by tapping and hearing the sound.

I'm wondering if there is a potential "ideal" frequency that could be created by tapping, that would result in ukuleles with the best sound, resonance, and sustain?

Maybe that's crazy...and I certainly don't have a wide enough collection to test my theory on other quality solid wood instruments (I don't have a Pono at this time, nor do I have a Kamaka). But I wonder if ukulele bodies could be tuned to a tapped pitch which would result in a better sound?

Thoughts?

I read that Kala hand tunes the ukulele tops in their Elite line by tapping. I have no idea what that means or if I've even reported it accurately, but I've had three, and currently have two Elite models and they all sound wonderful so you could very well be onto something.

I tend to tap any one I pick up - less so checking for frequency, more just a general feel on resonance. Frequency would surely change depending on body size.

Saying that, Banjo players (an area I have no expertise in!) do 'tune' their heads.

But then, a wooden uke is not tuneable, so I wouldn't personally get bogged down in frequency. If you tap it and it sounds lively like a drum, I then tend to expect the played sound will be lively with good sustain.

Kamaka hired deaf workers. While Chris Kamaka tapped and listened for the qualities he was looking for, the workers relied on the vibration to determine the wood possessed those qualities. Worked out well because they were unaffected by the noise in the workshop.

kookoolele said:

Kamaka hired deaf workers. While Chris Kamaka tapped and listened for the qualities he was looking for, the workers relied on the vibration to determine the wood possessed those qualities. Worked out well because they were unaffected by the noise in the workshop.

Click to expand...

That's it. I had them reversed...blind vs. deaf. My initial thought is the same...what aspect of that vibration (still ultimately sound) makes it "good" wood?

bazmaz said:

I tend to tap any one I pick up - less so checking for frequency, more just a general feel on resonance. Frequency would surely change depending on body size.

Saying that, Banjo players (an area I have no expertise in!) do 'tune' their heads.

But then, a wooden uke is not tuneable, so I wouldn't personally get bogged down in frequency. If you tap it and it sounds lively like a drum, I then tend to expect the played sound will be lively with good sustain.

Click to expand...

Thanks, Barry. I totally agree. At the same time, I'm curious and may investigate this further. I'll have to think about how I could test for the actual frequency. I'm not going to put loads of effort into this.

Choirguy said:

That's it. I had them reversed...blind vs. deaf. My initial thought is the same...what aspect of that vibration (still ultimately sound) makes it "good" wood?

Click to expand...

For years, Crayola had a man who was color-blind designing their colors. https://apnews.com/1611674d29abf010230350f264ed3003

I'm sure there's some science behind tapping on the top of the uke, but it seems like dowsing for water or alchemy.

You can find a lot of info online about luthiers who "tap tune" their instruments, looking for certain resonance or frequencies. Some focus on Chladni patterns. You can kill a few hours reading about it in different places. It is pretty interesting stuff

http://tommillerguitars.com/voicing/

EDW said:

You can find a lot of info online about luthiers who "tap tune" their instruments, looking for certain resonance or frequencies. Some focus on Chladni patterns. You can kill a few hours reading about it in different places. It is pretty interesting stuff

http://tommillerguitars.com/voicing/

Click to expand...

Thanks, EDW.

I'm pretty sure I'm not crazy--at least about this--and I'm betting that for the frequency range of the ukulele, there is an ideal pitch (or set of pitches) for the instrument...or set of pitches. I'm also guessing that some of the best ukuleles in the world approach this frequency range through trial and error (or sheer luck). That all said, while it would be lovely to buy and visit the best ukuleles in the world for an extended test and data collection, I certainly don't have the means to undertake that. It might also change with the type of wood used, but the frequencies should remain in the same ballpark.

But if that data were known, any luthier or company could work to match those frequencies (lots of trial and error) in their builds and produce consistent, amazing sounding instruments. As we all know, even the best companies and luthiers have specific instruments that don't work to plan. It might be interesting to study the frequency response of those instruments, too.

Again, more work for me than I can ever consider--but maybe a promising study for others.

Yes, It could be an interesting study. I would not doubt that the best instruments may have certain qualities that would relate, whether by design or chance.

Interestingly, sometime back I recall hearing of someone who advocated humming into the sound hole to find the resonance frequency of an instrument and tuning to that fundamental pitch. It may have been Joel Eckhaus of Earnest instruments, but I am not sure.

A local luthier, Brian Griffin, has made a number of shakers, each identical except for the tonewood. The variation in sound is quite surprising between them.

The concept of tap tuning has been around for some time now, the most famous examples are the Lloyd Loar mandolins and arch top guitars made by Gibson during the mid 1920’s. Roger Siminoff is a modern day proponent of the process and has written a book and several articles on the subject. I have had a number of conversations with Roger on the subject and he makes a good case for tap tuning as a method for duplicating superior instruments, much like top deflection measurements are used. With smart phone apps like IStroboSoft available, it is very easy to measure the resonant frequency of various parts and assemblies. I have been measuring the resonant frequency of my assembled bodies for many years now and have amassed enough data to be useful to me.
Brad

Interesting thread. It reminds me of discussions here on UU about dead notes on ukulele. The theory was that dead notes are caused when the resonant frequency of the uke body is the same as the note you are playing. Does that mean when you are tuning a top- you need to avoid common frequencies?

The short answer is, for me, is yes. As it happens, the body resonance of my Martin style sopranos is usually close to middle C, the same frequency as the C string. On a couple of occasions, the body resonance has been within 2 cents of that note, which in my opinion is too close and to avoid any wolf note issues I have tweaked the top to get at least a 10 cent difference. A story from Roger Siminoff; the Loar mandolins parts were tap tuned to notes of the C major scale. The top and back were a C and G, and the tone bars individually tuned. At the time, these mandos were quite expensive and not a big financial success. Also at the time, concert A was 432 Hz. These mandos became highly desirable after concert pitch was sweetened to A 440! Draw your own conclusions on that.
Brad

That's so cool that you do this, Brad.

Kurt at Southcoast strings had a lot of info on his site about relative frequencies,, particularly in regard to body size.

BuzzBD said:

The short answer is, for me, is yes. As it happens, the body resonance of my Martin style sopranos is usually close to middle C, the same frequency as the C string. On a couple of occasions, the body resonance has been within 2 cents of that note, which in my opinion is too close and to avoid any wolf note issues I have tweaked the top to get at least a 10 cent difference. A story from Roger Siminoff; the Loar mandolins parts were tap tuned to notes of the C major scale. The top and back were a C and G, and the tone bars individually tuned. At the time, these mandos were quite expensive and not a big financial success. Also at the time, concert A was 432 Hz. These mandos became highly desirable after concert pitch was sweetened to A 440! Draw your own conclusions on that.
Brad

Click to expand...

I'm a tap dancer and when one talks about tapping, that's what I think, even if someone is talking about something else. I was just thinking about it and taping on a uke just doesn't seem good. But to get serious, lots of tap dancers have their favorite woods to tap on. Studios are notorious for using plain old plywood and there is endless debate about what wood tap floor gives the "best" sound. People carry around their own folding portable dance floors. Anyway, when you test a dance floor you tap it with a fifty cent piece.

Rllink said:

I'm a tap dancer and when one talks about tapping, that's what I think, even if someone is talking about something else. I was just thinking about it and taping on a uke just doesn't seem good. But to get serious, lots of tap dancers have their favorite woods to tap on. Studios are notorious for using plain old plywood and there is endless debate about what wood tap floor gives the "best" sound. People carry around their own folding portable dance floors. Anyway, when you test a dance floor you tap it with a fifty cent piece.

Click to expand...

Do you tap it with a modern, post 1965, fifty cent piece? Or use an older solid silver half dollar? I'll bet you could start a whole new subset discussion within the tap dance community regarding which gave the most accurate results.

Tapping Ukes

I often tap the top and back of a new or prospect ukulele.

I think it gives a slight indication of its resonance. I've tapped some inexpensive ukes that sounded like a muffled box when I tapped it.

Some laminates that sounded dead and others that sounded echo-y and excellent. And they played pretty much the same.

Those with the thinner tops and/or back seemed to produce a louder sound when tapped. Almost all of those had a more open resonance and longer sustain.

You get a lot of sound from the vibrating back as well as the top.

I bought a Limited Edition Pono MTSH-C-MS Master tenor with a Mahogany body and Cedar top. The description stated: Noa then hand selected the 16 western red cedar tops for this model, going through piles
of instrument grade sets, feeling for stiffness, weight, and resonance (tap tone).

I don't have a contemporary Pono PC Cedar/Mahogany to compare it to. So, I can't say if the tap tone process made a difference in sound or not.

I have read that luthiers who hand-scrape their tops, especially if the tops have a varying thickness to them, use tapping to make sure the sound produced is consistent and without quieter areas. (I'm not saying this exactly correct, but I think you get the idea.)

I have read of owners returning a high-end uke because it didn't sound quite right and the luthier removing the top to re-tune the top. Resulting in an instrument that better met the owner's liking.

Kenn2018 said:

Do you tap it with a modern, post 1965, fifty cent piece? Or use an older solid silver half dollar? I'll bet you could start a whole new subset discussion within the tap dance community regarding which gave the most accurate results.

Click to expand...

Actually, In all honesty I've been told that, I've not actually tapped one with a fifty cent piece. Even if I did I wouldn't know what to listen for. However, I have tap danced on several different surfaces and I know that I don't sound any better on an expensive floor than I do on a cheap particle board floor. Proving once again, you can't buy talent. Kind of like my ukuleles.