Official Luthiers Forum!

Thanks again to everyone who was able to join this month's roundtable meeting. We had a nice group today and a good discussion about achieving the desired top thickness.

In the meeting we looked at a spectrum analyzer tool specific to luthiers called Luthiers Spectrum Analyzer. Here is a link it - https://alainlambert.wixsite.com/luther ... m-analyser

If you would like to submit anonymous feedback on topics, experience, etc... please fill out the form here - https://forms.office.com/r/HHEni87fAP

Recording:
Direct Link - https://youtu.be/Jpux0fZEDj8
Meeting Archive Playlist - https://www.youtube.com/playlist?list=P ... d2qUiezNGN

Attendees:
Brent Tobin
Jay DeRocher
Kent Fishburn
Don Parker
Bob Gramman
Michael Colbert
Steve Smith
Ken Nagy
James "Wud" Linsley
Brad Combs

See you next month!

Brad

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FWIW, the FFT I use is iAnalyzer on an iPhone. It used to be 10$ but it’s been bought out by profiteers and is now stupid expensive, however, the free demo version still gives 10 seconds of recording time which is ample. Easy peasy and no need for complex mic/computer setups. I tested it in the appropriate freq ranges with my DynAudios and a tone generator and found it accurate to within a cent. YMMV

Can’t wait to watch this one. I had family pictures. :-/


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By ear I checked the tops I have. They all have a high tap around the high e string, and a low tap around the low E string. Interesting. One, the longer skinny Sitka for a baroque has a low C sound. It will only go to A.

Sometimes I hear lower tone, but not until they get thinner. Audacity didn't pick any up.

But those are only tones on a free plate. They will be different when they are glued on. They are also too thick; some more thick than others. They do give an idea of what the stiffness is though. Overtones are what is going to make the big difference. You can't really hear them until the braces are on, and the edges are clamped/glued.

The Hemlock piece is E to e, but it is .160" not .130" or so. I forgot that I had set it aside when I was retrieving the plates, and the guy was loading them into the sander. It missed the last 1 or 2 passes. It should feel 86% stiffer! It is just as stiff lengthwise.

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Why be normal?

Thanks for the tip!

I was playing with it this morning wishing it had an image hold function. Other than that, it’s really handy to have a simple analyzer app while carving braces etc…

Best,M

Trevor Gore used Visual Analyzer 32 on his class on Robbie's site. Its now a legacy version- sorry I don't remember what he specified in the course. The version I downloaded is Visual Analyzer v.20221 r1

I signed up for this episode but a family gathering superseded it. REally sorry I missed it too.....

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Measure Twice,

Karl Borum

Visual analyzer - that’s the one I was trying to think of! It’s super powerful but has a lot we don’t need I think. Seemed like there was a fair amount of knob turning needed to get it going. I like the Luthier Spectrum Analyzer. So easy even I can do it.


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