The Hub

I did a pretty big update to my web tools last week. These are updated from the older versions I had up on celestialinstruments.com. There’s an updated FFT tool now, plus mode detection for guitars and plates, wolf note detection, played-note energy transfer, monopole mobility, plate thickness calculation, and 1/2/3/4 DOF modeling that can be prefilled from FFT data. The part I’m most excited about is being able to fit a measured guitar re…

Hey folks, I put together a video showing how I measure the long, cross, and transverse frequencies on guitar top plates before thicknessing, following the Gore method. I also walk through using the calculator I built (based on Trevor Gore’s equations) to get target thickness and track density / young's modulus. Fair warning: the video’s a bit YouTube-y in tone thumbnail faces, a little energy for the algorithm, but the content is genuine…

I've been testing all my top and bracewood to find the best combination of stiffness and density, optimize plate thickness, etc. I started with Nicoletti's spreadsheet which calculates both stiffness and density, but since I was also testing deflection, I decided to compare the flexural modulus using that method (with the formula from T. Gore's book) on the same plates and bracewood. Unfortunately, I'm having trouble getting a satisfa…

Initial frequency analysis of this D28 copy (done with a temporary 35g bolt-on bridge and the back plate taped on) is VERY LOW. Main air resonance 83.5hz and top monopole 156.6. It's standard Martin scalloped X-bracing with a torrefied Adirondack top. Since I can still easily access the bracing, I'm thinking of going in and laminating wood on top of the X brace to stiffen it. Other options would be a very light bridge, though I'm not…

For folks familiar with the Gore / Gilet books and the top thickness calculations in section 4.5. I made a web based calculator to do the nasty spreadsheet math... So this is for once you've weighed and measured your top plates and then found the long, cross and transverse resonances it gives you the target thickness to hit a particular frequency for the long resonance of the plate. Just sharing so folks don't have to do the math for bu…

Hi everyone, in the loothalong I shared this spreadsheet I put together a few years ago, based on D'ADDARIO phosphor bronze strings data, and Elixirs' as well. There are a few different tables for standard 6 strings, fanfrets, harp guitars, baritone and 12 strings. You choose the relevant table, input the scale length, string gauges and tuning, the spreadsheet will give you individual string and total tension in lb and kg. For the fanfret…