What would you call these modes

[kiwigeo]

Two interesting Chladni patterns I snapped while doing tests on my falcate braced classical. At higher frequencies the nodes seem to follow the bracing more than at lower frequencies. Any idea what youd call the modes in the photos below?

[Trevor Gore]

Any idea what youd call the modes in the photos below?

Punch and Judy?

There are endless shape permutations as you go higher up the frequency range, many of which are difficult to categorise under the usual nomenclature systems, and some that you'll never see again. A generic name I've heard is multi-lobe modes.

[kiwigeo]

The top one reminds me of one of your equations.......therefore I shall call this mode "Trevor".

[Trevor Gore]

I feel honoured!

[kiwigeo]

The other mode is on the backside of the guitar so I shall name it.......Kim.

[Dominic]

Nice set up to get such clean lines at those high frequencies Marty. I wonder if there is a frequency that would outline all the braces?. You got a ubeaut analogue one from that guy didn't you? My sig gen works great but I only have a shitty little component amp and need something cleaner and more powerful.

Dom

[kiwigeo]

Nice set up to get such clean lines at those high frequencies Marty. I wonder if there is a frequency that would outline all the braces?. You got a ubeaut analogue one from that guy didn't you? My sig gen works great but I only have a shitty little component amp and need something cleaner and more powerful.

Dom

Hi Dom,

Yes there was one mode I got that pretty much outlined all the top bracing quite nicely. The signal generator is a Bradley I got from the US. Its got a 50 watt amp built in and Im using a fairly large speaker as well.

[ScottC.]

I came across this chart, I don't know if you have seen this
http://en.wikipedia.org/w/index.php?tit ... svg&page=1

[ozwood]

The top one reminds me of one of your equations.......therefore I shall call this mode "Trevor".

Love it !

[Trevor Gore]

I came across this chart, I don't know if you have seen this
http://en.wikipedia.org/w/index.php?tit ... svg&page=1

I hadn't, but it looks like free plate modes, which I've never found particularly useful, though some people do. There's lots of other such diagrams in Fletcher and Rossing and more pics here.

[ScottC.]

I don't know what they mean, maybe someday I'll make some sense of them?
Thanks, Scott C.

[charangohabsburg]

I came across this chart, I don't know if you have seen this
http://en.wikipedia.org/w/index.php?tit ... svg&page=1

I hadn't, but it looks like free plate modes, [...]

I agree, it looks like that, and I discovered that it actually was used to illustrate free plate modes (here, on German wikipedia).

[...] which I've never found particularly useful, though some people do.

I don't know what they mean, maybe someday I'll make some sense of them?

I think that mainly "violin people" find free plate modes useful, which makes sense because they can pop off tops or backs and reassemble the instrument without damaging it in the process, which allows to discover relationships between the free modes and the sound of the finished instrument. I believe that with a guitar, taking off the top and putting it on again involves too many steps that compromise the integrity of the involved parts (first of all the top itself, but also the linings, binding and purfling, where the latter ones may or may not have a perceivable impact to the final result).

[ScottC.]

I thought they would be useful to somebody!