Hmmm... it's truly amazing that there's one physics for lutes and an exactly opposite physics for globular flutes (which certainly behave the way Bob described). Maybe it's the 'f' on the start of the name that reverses things, lol.
Seriously, the resonance of the fixed sized chamber is determined by how fast air can move in and out. bigger hole=more air in a given time=faster movement=higher frequency. Run that by your physicist friend. Michael Thames wrote: > Dear Doctor, > Actually I just looked this up in my book here, and I will explain it > like > this. > One needs a fixed, solid air cavity with an opening. As one > increases > the size of the opening it lowers the air space resonance, period!that is > science. Bob actually has it ass backwards! > I actually don't really get what Bob is talking about because he is > not > using science and I have a hard time following him. > Bob talks about blowing into the soundhole and hearing something. > What Bob is actually hearing is what is called "mode coupling". that is > a > phenomena were you are hearing both the air resonat frequency coupling > with > the frequency of the vibrating plates to create one frequency,as on a lute > or guitar. > If however, the plates where not able to vibrate and had a fixed air > cavity you would only hear the air resonance frequency. > This really is not up for debate it is pure science, no matter how Bob > trys to sell it! > Michael Thames > Luthier > www.ThamesClassicalGuitars.com > Site design by Natalina Calia-Thames > ----- Original Message ----- > From: "Doctor Oakroot" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Thursday, December 11, 2003 9:41 PM > Subject: Re: a rosette by any other name... > > >> Michael, your physicist friend didn't understand the problem. As Bob >> described it the amount of beer in the bottle during the experiment was >> fixed. Only the size of the opening changed. >> >> Michael Thames wrote: >> > I've just spoken to my physicist friend, and he explained it like >> this. >> > When you have a beer bottle and blow into it, the pitch changes > according >> > to how much beer ( air volume) is in the bottle. >> > Bob, what has the most significant effect on the pitch is how much > beer >> > you consumed during your experiment! >> > Michael Thames >> > Luthier >> > www.ThamesClassicalGuitars.com >> > Site design by Natalina Calia-Thames >> > ----- Original Message ----- >> > From: "BobClair or EkkoJennings" <[EMAIL PROTECTED]> >> > To: <[EMAIL PROTECTED]> >> > Sent: Thursday, December 11, 2003 8:48 AM >> > Subject: a rosette by any other name... >> > >> > >> >> >> >> Philippe Mottet <[EMAIL PROTECTED]> writes: >> >> >> >> > I think M. Thames is right when he mentions that a bigger opening, >> a >> >> > rosette with a longer diameter and an airy (?) motive, tends to >> favor >> > bass >> >> > and fundamental resonances. >> >> >> >> And you, also, would be incorrect. I'm not trying to be mean or rude, >> >> you >> > are entitled to >> >> believe whatever makes you happy. But unlike some more subjective >> >> things, >> > like whether a >> >> note is "sparkling" or not, the pitch of the main air resonance of a >> > guitar or lute or violin >> >> and what happens to that pitch as you make the hole(s) in the top >> >> smaller >> > (it goes down) are objective >> >> things that you can easily measure with a simple experiment. They are > no >> > more influenced by how you think >> >> or feel about them than is the height of the Eiffel tower. >> >> >> >> As for "this particular rose design causes those particular tonal >> > qualities" - there are just way too many >> >> variables involved. Making such a statement on the basis of one or >> two >> > instruments is nothing more >> >> than a superstition. To make any meaningful statement you would have >> to >> > make two batches of otherwise >> >> identical instruments with twodifferent rose patterns and then show >> >> that, >> > on average, a pair with different >> >> roses had a significant difference in the quality you were testing >> for >> > compared to a pair with the same rose design. >> >> At this point it would be wise to recall a statement attributed to >> >> Michael >> > Lowe: "An exact copy of a historical instrument ? >> >> I can't even make an exact copy of one of my own instruments." >> >> >> >> Pendulums ? Divining ? Dowsing? Mysterious Energy ? My contract with > the >> > Physicist's Union has a clause limiting >> >> the amount of time I have to spend arguing with believers so I will > just >> > leave with a single >> >> word: "unlikely". >> >> >> >> >> >> .....Bob >> >> >> >> ____________________________________________________________ >> >> ____________________________________________________________ >> >> >> >> Replies: (remove the "ZZZZ") >> >> >> >> Ekko Jennings: [EMAIL PROTECTED] >> >> Bob Clair: [EMAIL PROTECTED] >> >> >> >> >> > >> > >> > >> > >> >> >> -- >> Rough-edged songs from a dark place in the soul: >> http://DoctorOakroot.com >> >> > > > -- Rough-edged songs from a dark place in the soul: http://DoctorOakroot.com
