Spectrum change with age

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AKEric
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Spectrum change with age

Post by AKEric » Tue Dec 03, 2019 3:39 am

I was talking with the new owner of my latest guitar about the likelihood of it sounding better as it "settles in" with more use. It's fairly well accepted that as instruments are played more and age, they tend to sound better; or at least different. This got me thinking, and wondering if anyone has used the spectrum analysis process to compare the resonances of an instrument with a with a few miles (Kilometers?) under its belt to the spectrum from when it was brand new. I imagine seasonal and even daily climate changes can affect the data, but it would be interesting note if there is an obvious shift in the three main resonances over time and use.

Just curious.

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lamanoditrento
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Re: Spectrum change with age

Post by lamanoditrento » Tue Dec 03, 2019 9:45 am

I have no idea how the spectra would change but I'll add some thoughts I've had on age and settling in.

I remember in Nigel Froster's ebook, he mentions UV light increasing stiffness, which would certainly affect the frequency response. So aged guitars would slowly increase their UV exposure.

Torrification, seen as a facsimile for age, certainly affects the material properties and therefore would affect the response. I also remember something vaguely about humidity cycling decreasing the sorption properties and increasing dimensional stability of wood.
Trent

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Trevor Gore
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Re: Spectrum change with age

Post by Trevor Gore » Thu Dec 05, 2019 7:38 am

I've found that if I use "old" wood (that I've had for at least 5 years), the guitar seems to get louder with age but the spectrum remains much the same. If I use "new" wood, cut and dried for less than 2 years, the guitar gets stiffer as it ages and whilst the shape of the spectrum remains recognisable, the resonant frequencies rise. So it seems that seasoning (cycling the wood through temp and humidity changes over time) makes a difference and being able to adjust resonances with side mass and other techniques is a useful thing to be able to do.

AKEric
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Re: Spectrum change with age

Post by AKEric » Sun Dec 08, 2019 11:48 am

Thanks for both of the replies. It's interesting to me, so I'll try to track it over time.

Thanks again.

Eric

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kiwigeo
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Re: Spectrum change with age

Post by kiwigeo » Sun Dec 08, 2019 5:08 pm

Don't forget the obvious...with time your playing usually gets better :mrgreen:
Martin

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johnparchem
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Re: Spectrum change with age

Post by johnparchem » Mon Dec 09, 2019 4:34 am

I noticed that the resonance frequency shift with changes in the string height off the top in the saddle position. So if you ever needed to adjust the action, you might see a change.

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