-------- Original Message -------- Subject: Re: [Hornlist] Who'd a thunk it? Date: Wed, 20 Apr 2011 20:20:59 -0700 From: Richard V. West <[email protected]> To: The Horn List <[email protected]>
Bill: Did you "thunk" your computer? Maybe its CPU is dead and needs to be replaced by a new brass one. Richard in Seattle Where the paint never dries On 4/20/2011 4:42 PM, William Gross wrote: > Most peculiar, on my other computer all I got from cabbage was a blank > screen. I thought he had joined the "less is more" crowd. I long on a > different machine and find it's even better than that. He actually provides > some interesting information. > > On Wed, Apr 20, 2011 at 2:21 PM,<[email protected]> wrote: > >> Howard wrote: "I don't want to cut the bell on my N series 8D because >> the >> bell rings >> forever. I suspect cutting it would destroy that. I remember one day >> up in Boonsboro Walter Lawson was telling me how their bells ring >> better than others. He whacked my N series 8D's bell with his finger, >> and it probably still hasn't quit ringing. He was visibly shaken, and >> immediately stopped telling me about that aspect of his bells' >> superiority!" >> >> Dave W wrote >> I have always had enormous respect for Walter and his work, but this is >> one thing I could never understand. What does a ringing bell flare >> mean? >> What does the old "thunk test" prove? You could whack a steel mixing >> bowl >> and it work ring for a week. But would that bowl make a good horn >> bell? And, >> all other things being relatively equal, what would it tell you about a >> flare that rung and rung versus one that seemed dead when you whacked >> it? You >> don't whack a horn to get the sound out. You vibrate the air column. >> If a bell just kept ringing and ringing, would that not actually >> interfere >> with attacks, or with notes speaking, when playing runs? And if not, >> why >> not? >> >> I'm sure that a certain amount of "ringing" is probably good for a bell >> flare to have, but isn't possible to have too much of a good thing? I >> still haven't puzzled this out, and I sure would appreciate some >> enlightenment. No one I've talked with about this can give me a >> satisfactory >> explanation, and I'd love to have one. >> ************ >> Cabbage says: >> >> Lawson did some studies of how horns sound with annealed and unannealed >> flares. (These were published in the Journal of the Acoustical Society >> of America some while ago.) An annealed flare is one which rings for a >> while when you strike it; unannealed flares generally will not. >> >> The article indicates that the tone quality for the two kinds of bells >> was most >> different at high dynamic levels. The difference was a slight one: in >> the annealed >> flares, some of the higher frequency harmonics were enhanced by 3 dB or >> so. The effect was >> different for yellow brass bells compared to nickel silver bells. >> >> If the flexibility of the wall material matters, then there are two >> influences it could have. The first is that the walls could flex >> enough to produce >> audible sound. The second is that the walls could flex enough to >> change the >> profile of the air column. >> >> I am aware of a study of metal organ pipes which demonstrated the >> following: if an organ pipe oscillates strongly enough to make audible >> sound from >> the surface, it will also change its profile enough to shift in >> frequency. >> This is not desirable, so organ manufacturers make organ pipes stiff >> enough to >> prevent it. >> >> How does this relate to the horn? Here is some background. When sound >> goes from your lips toward the bell, most of it reflects back to the >> lips. >> The low frequency parts tend to reflect in the narrow throat of the >> bell; the >> higher frequency parts of the sound reflect further out in the wider >> part of >> the bell. This means that the bell interacts most strongly with the >> high >> frequency harmonics in the sound. >> >> Some more background: as you play louder, the sound level of the >> harmonics >> increases. However, the increase of the higher frequency harmonics is >> much greater than the increase of the low frequency harmonics. (If you >> record a horn played quietly and play the recording with the volume >> knob up, >> it doesn't sound like a loud horn.) So the relative spectrum shifts, >> enhancing >> the higher frequency harmonics. >> >> Most of the tubing of your horn is too thick and has too small a radius >> to oscillate very much. The situation is different for the bell: it is >> much easier >> to bend the bell than (say) the surface of the leadpipe. >> >> So what happens when you play loudly? The higher frequency parts of the >> sound become more significant. Those are the parts of the sound that >> interact with the bell. As they interact with the bell, the bell can >> oscillate >> and produce sound of its own. I speculate that this sound from the >> bell can be audible and therefore contribute to the spectrum. Unlike >> the >> organ pipe, however, the frequency of the horn will not change, since >> the playing frequency depends on how the low frequency parts of the >> sound interact with >> the narrow throat of the bell, which is not vibrating enough to change >> the >> profile of the instrument. >> >> Lawson studied the spectra of the sound produced by horns with annealed >> and unannealed flares. But he did not determine how big the >> oscillations >> of the flares were, or whether those oscillations might produce audible >> sound. >> >> Some while ago, I participated in a blind test of a horn played with >> annealed >> and unnanealed flares. (The flares had to be changed in a different >> room: >> it is easy to tell by the clanking noises whether someone is putting an >> annealed or unnanealed flare on a horn.) I was able to distinguish the >> two kinds of bells. The difference was slight, but apparent at loud >> dynamic levels, when the tone quality of the annealed flares was a >> little >> less blatty. (I apologize for using such obscure scientific >> terminology.) >> >> Still, I think the ringing of the bell is quite a minor aspect of a >> horns sound. >> If you play a loud note, then stop abruptly, do you hear the bell >> ringing afterwards? >> Probably not. >> >> Gotta go, >> Cabbage >> >> >> >> _______________________________________________ >> post: [email protected] >> unsubscribe or set options at >> >> https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/bgross%40airmail.net >> > _______________________________________________ > post: [email protected] > unsubscribe or set options at > https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/hornfella%40comcast.net > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1321 / Virus Database: 1500/3585 - Release Date: 04/20/11 > > _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
