Acoustic Guitar Resonance Problem

[ggunn]

Yeh thats the speed reading thing and my current stress levels. But the first thing you do with those elusive rattles is hit the note and grab everything you can reach with your other hand til you nail it. I have chased rattles all over guitars for hours before.

Sound doesn't travel through all solids better than air by the way, in many it travels very inefficiently. Its that mass/stiffness thing again.

Inefficiently by relative standards, I guess, but sound velocity is proportional to mass. Water isn't very stiff, but sound travels faster/better in water than in air.

 

[Richard Monroe]

Well, Ggun, water may not be that stiff, but 32 feet of sea water or 33 feet of fresh water is equal to one atmosphere of pressure, which is 26 miles or so of air. That makes water many, many, more times dense than air.-Richie

 

[jmcelroy]

It sounds like what you have come up against in purely musical acoustic terms...

That, Muttley, was a beat down response if I've ever seen one. One day somebody is going to stumble on this thread and be really grateful to you!

 

[muttley600]

Inefficiently by relative standards, I guess, but sound velocity is proportional to mass. Water isn't very stiff, but sound travels faster/better in water than in air.

It's proportional to mass and stiffness. Take putty for example not very good at transmitting sound at all but very good and stopping it. With woods the speed of sound varies a lot from type to type and piece to piece. Many solids have high mass and low stiffness many barely transmit sound at all. The speed of sound in gasses is also different depending on several factors relating to mass stiffness, pressure etc, but you know this,

 

[Light]

Personally, I've got no problem with sticking a little piece of felt behind the nut. Not, perhaps, the most elegant solution, but it works, and save you a bit of money. We do that fairly frequently with some archtops (particularly old Epiphones with the Frequencator tailpiece. A new nut would probably also do the trick, but if it is working right otherwise, why?


Light

"Cowards can never be moral."
M.K. Gandhi

 

[Richard Monroe]

Thanks, Light. I'm always happy to see your input on stuff like this.-Richie

 

[jmcelroy]

Personally, I've got no problem with sticking a little piece of felt behind the nut...

Thanks, Light!

(In the interest of full disclosure, because I had just read your post before replying I almost wrote "Thanks, Nut!" How great would that have been? )

 

[ggunn]

Well, Ggun, water may not be that stiff, but 32 feet of sea water or 33 feet of fresh water is equal to one atmosphere of pressure, which is 26 miles or so of air. That makes water many, many, more times dense than air.-Richie

That was my point.

I'm a diver, too.

 

[muttley600]

That was my point.

I'm a diver, too.

So now water is a solid??? Lets finish this off, a couple of questions.

Is the speed of sound in gas/liquids/solids dependant on mass or mass/siffness ratio. Is the speed of sound in for example, playdoh (solid) greater or smaller than the speed of sound in water (liquid) or air (gas)? You can pick the pressure constant and temp. You can even include figures for impedance. Finally the deal breaker, is you statement "As we've discussed in other threads, since sound travels in solids much more efficiently than in air,..." true?

I'm a diver as well by the way. Are you guys Padi or Bsac over there? I've never dived down your way.

 

[ggunn]

So now water is a solid???

[...]

I'm a diver as well by the way. Are you guys Padi or Bsac over there? I've never dived down your way.

Water certainly can be a solid.

Actually, I'm certed by PDIC, but my wife is certed by PADI. We do virtually all our diving in the waters around Cozumel.

And yes, the velocity of sound in an elastic medium is the square root of the elastic bulk modulus divided by the density of the medium. I had to look it up in the text of my upper division engineering acoustics text. Sound actually travels slower in a denser medium, all else being equal. That's what I get for trying to remember stuff from a course I took 20 years ago. ;^)