I recorded some tap tone and analyse the frequency.
The top resonance is a high B3 253Hz and body resonance B2 123Hz
It's higher than I had hope for, Now I might just shoot for a heavier bridge to bring down the resonance or thin the perimeter to bring down the resonance.
Body resonance @ 123 Hz B2
Top resonance @ 253 Hz B3
I began to sand the top to bring down the resonance mainly on the lower bout perimeter.
After some vigorous sanding, I manage to bring down a few Hz; still have a long way to go.
Sanding the top.
Body resonance after sanding
Top resonance after sanding
After somemore sanding the resonance points didn't change too much and I realise I can't sand anymore.
The edges are too thin about slightly over 1 mm.
Now what I can do is to reach in and shave down the braces but before that I need to consider what other actions to take.
I could try to shave the back braces to increase the back coupling.
The body resonance should be within range but top resonance is a bit too high.
Anyway I think I just do up the binding and glue in the bridge.
If need to I adjust the back bracing to add more coupling.
Body resonance @ 106Hz G#2
Top Resonance @ 247Hz B3
Top Resonance @ 214 Hz G#3
After binding and purfling are glued and the bridge is on, the final resonance range is
Body: 104 Hz T(1,1)1 Top: 195 Hz T(1,1)2 and 227 Hz T(1,1)3
According to Trevor Gore (an Aussie Luthier who deal with tuning guitar in a more scientific method), the average values are 100, 190, 240; mine is quite close.
What Trevor aim for are 3 to 4 semitones apart for T(1,1)2 and T(1,1)3
Mine is a G and A about 2 semitones apart.
Let's see how it sound and I adjust later.
This is an active back so you can see 3 peaks very distinctly.
If non-active back, the 3rd peak will be heavily suppressed.
I think the active back does work, it makes the guitar have a fuller tone
(I only managed to hear a while the sound of the open strings before the bridge gave way)
T(1,1)1 Body resonance (or Air resonance)
104 Hz G#2
T(1,1)2 Top Resonance
195 Hz G3
T(1,1)3 Top Resonance
227 Hz A#3
Welcome to my guitar building blog.
This blog describes my journey into the world of guitar building.
I like to share my experience of building and hopefully it can be of some help to all the guitar making enthusiast.
Hope you enjoy my blog post!
Showing posts with label Tuning box. Show all posts
Showing posts with label Tuning box. Show all posts
2012-01-13
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