Official Luthiers Forum!

+1. Much to be learned with this tool. T

Has Audacity provided a way to zoom the output display yet?

Bob, if this stuff is already bending your brain, I'd stick to VA, as there is more info around on how to use it for guitar work. There's plenty more stuff on the ANZLF site. Audacity is preferred by Mac users because VA is for Windows only. I've tried both and still prefer VA, which has things I use that Audacity doesn't have. You don't need a super-hi-fi sound card to do what's required. I'm using the built in sound card of my Toshiba Tecra laptop. Works fine.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Thanks Trevor, Having only recorded "music" I am of the mindset that a better sound card is a must but if you say a laptop sound card will work fine than I will go ahead and install VA on mine. I am sure I need the help so I will sign up on ANZLF and nose around a bit.

Thanks again for the help and suggestions.

Cheers,
Bob

When I read back to back posts above, by Trevor and Duh Padma, I definitely heard wolf notes in my brain.

Before my enlightment, Gore & Gillet books, I was trying to figure the tap tune, plate thickness thing out and started to look at Haitian voodoo for answers, and found the voodoo made more sense!!!!!

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MK5acoustics.com

I would love to get the G&G books but I can't put out that kind of money right now. I am trying to scratch the money up for a new band saw and it has to be done pretty quick. My 45 year old craftsman just started screaming on me and I pulled it apart to find the bearings are shot. I could replace them but that is a little like trimming a dead tree.

But I have the G&G books on my list along with a few others... That list keeps getting longer for some reason.

Bob

[quote="Trevor Gore"]Has Audacity provided a way to zoom the output display yet?

Yes, there is a zoom feature on the top right of the control panel. I am sure I can and should learn more about using Audacity and at times it seems far more sophisticated than what I am using it for. But it certainly helps me reference what has worked and not worked and it has given me a baseline. I have become a bit addicted to tapping and recording everything including a three ply spruce top I glued up in a heat press. Results are surprising. Tim

I have never used a spectrum analyzer for anything but I have been tapping on wood for a few years now. I actually started tapping on guitars a long time ago but it was mainly to find rattles and loose braces when I inspect a guitar. Now I tap on anything to hear what the tone sounds like.

I installed Visual Analyser last night and messed around with it but have ZERO clue what to do with it... Looks like I am going to have to do a lot of research to figure out how to use it and then how to use the data it puts out... Good thing I don't give up easily on trying to learn something... This one may give me a good run for my money though.

Bob

That works on the spectrum display?

I'll have to dig around some more and update to the latest version. Thanks.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I use the waveform display the most but the spectrogram does have a vertical scaling feature. I really do need to get your books by the way. Even without them I have learned from your posts here and elsewhere, and for that I thank you. T

It's a horizontal one (frequency) that's really required. I'll keep looking...

No worries. Thanks for the kind words, Tim.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I spent the afternoon with Audacity and I'm ready to try VA. I couldn't get the horizontal (x-axis) adjusted except to move to log-scale from linear, but I much prefer the way that Trevor plots the less than 1000 Hz frequencies (I'm back in Volume 1 today); also I couldn't figure out how to save the spectrum plot as a picture, only was offered a text extension. Anyway I'm going to give VA a try, after I have a beer (or two). On the positive side, I will say that the peaks in the spectrum plot in Audacity agreed with the Chaldni pattern frequencies I dialed in earlier in the day and that is reassuring to someone who doesn't always readily adjust to technology.

A quick glance at the Android store showed half a dozen free FFT apps. Don't discount your smartphone! It's what I use and it's great.

I have a question. Please keep in mind I'm new to building and I am in no way trying to discount tap tuning or any of the fascinating posts in this thread. My question is this:

Some of the most expensive and sought after guitars are pre-war Martins (I was at Gruhns in Nashville looking at OO's and asked if they had any that weren't on display and was told they had a pre-war OO and that the price tag was $12,000). Do we know if the folks building these instruments had any clue as to any of the things being discussed here? Obviously they lacked the technology that we have for measuring some of this stuff, but were they tap tuning? Perhaps more by ear than anything?

Again, I mean no disrespect. I'm not in any way against the use of technology to make things easier and better. I'm an IT guy for cryin' out loud. It's just something I though of while reading this thread and having my mind thoroughly blown.


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Gerard (my partner in crime on the book) has a wall in his dry room, where he does all his bracing and Chladni pattern testing, on which he's written the resonant frequencies of all the best guitars he's had through his workshop since he started in 1976. Also, I tested a whole bunch of master quality Spanish classical guitars when I was working on the book. When you look at all that data, certain patterns emerge as to what modal frequencies "work". Now, whether they got there by chance or whether they got there by design is a matter for debate. My feeling is that the steel string ones got there mainly by chance. I say that because generally the SS factories did not work on the braces after the box was closed, but had design parameters that put them in the right general ball park, so some of them actually hit the target spot on. On the other hand, I'd say the Spanish classicals got there by design because of the individual attention they received and the fact that there was evidence of work on the bracing after the box was closed. So whilst these Spanish masters would not have used the same language as I use (the language of engineering and physics) to describe what they were doing and why, to me there is little doubt that they were heading for the same places that I target.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Thanks so much for the reply Mr. Gore. I find both this topic, and the process of luthier's past, to be very interesting.

Thanks again.