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Re: [Phys-L] sound



Hi

There are (at least) three additions to make regarding the bugle. One is the mouthpiece is a small cavity with its own Helmholtz resonance. This has an effect on the strength of the frequencies available to the rest of the tube. The second is the impedance mismatch at the open end of the horn. To set up a resonance some sound has to reflect from the open end of the horn. The gradual change in diameter reduces the mismatch (allowing some sound to leave the horn which is desirable and why brass instruments are louder than instruments with smaller horns) but doesn't eliminate it (otherwise no resonances would be possible). Different wavelengths (due to different lip buzzing driving frequencies) reflect at different diameters so different frequencies 'see' a different length tube. These two effects apply to the fundamental as well as harmonics. Part of the 'bright' or 'brassy' sound of a brass instrument has to do with the shift in higher overtones from harmonic to not exactly harmonic. Also, a closed ended tube only has odd harmonics present in the first place.

I am in the process of constructing an online text for an introductory sound course and would appreciate any suggestions:
http://homepages.ius.edu/kforinas/S/Introduction.html

kyle


------------------------------

Message: 15
Date: Fri, 12 Apr 2013 07:21:22 -0400
From: "Anthony Lapinski" <Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>>
To: phys-l@phys-l.org<mailto:phys-l@phys-l.org>
Subject: [Phys-L] sound
Message-ID: <fc.000f54740994abca000f54740994abca.994acab@pds.org<fc.000f54740994abca000f54740994abca.994acab@pds.org">mailto:fc.000f54740994abca000f54740994abca.994acab@pds.org>>
Content-Type: text/plain; charset=UTF-8

Does anyone know how a bugle produces different notes (as it has no keys,
valves, slides, etc.)? I know the instrument when played is physically
closed, but it behaves like an open pipe due to the bell's conical shape.
So the harmonic series is fn = nv/2L The length of the instrument is
constant, so does the player just blow/buzz his/her lips faster? or with a
higher frequency? That changes the harmonics/frequencies, but does that
change v in the equation? I thought v was the speed of sound in air (343
m/s) for brass instruments. I'm a bit confused with some of the finer
details of this "simple" instrument.



------------------------------

Message: 16
Date: Fri, 12 Apr 2013 08:01:05 -0400
From: Marty Weiss <martweiss@comcast.net<mailto:martweiss@comcast.net>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] Car repair
Message-ID: <BB09D706-CCFD-4847-B4F2-98389E97201F@comcast.net<BB09D706-CCFD-4847-B4F2-98389E97201F@comcast.net">mailto:BB09D706-CCFD-4847-B4F2-98389E97201F@comcast.net>>
Content-Type: text/plain; charset=us-ascii

two things here: first, my story is to relate that you cannot modify or repair a car now like we did back then. Few people even back then took a whole car apart, but the story goes to show that you could if you wanted to... that doesn't exist any more. Maintaining cars then meant the brakes (still can do), the carb. (who will tackle fuel injectors and the electronics that go with them??? not too many people can or want to do that.), alternator? ( can you stil take that off and restore it back in an hour like the guy in college? I doubt it.). The list goes on and on of things that we used to do fairly easily that simply cannot be done any more.... Take the radio. I could take an old radio out of my old Rambler, modify the dash to accept a new radio, install it, wire it, and listen to rock and roll in a couple of hours. Could you do that now?
Second: Well, among many young people the interest is still in cars, but they have realized that they cannot simply strip down a car like the old days. Sure I know two sons of friends who can do the brakes on their mom's Ford Explorer in the yard. But when it comes to engine work? They take it to their place of business... one works for PepBoys and the other works for a Ford dealer.. both are highly trained mechanics. They used to take apart and out together simple engines in their parents' garages, but now? They must go for training every six months to maintain a certification to work on cars at the shop.
Someone in this thread stated that the basics of the automobile are the same... yes, it's still the internal combustion engine and the brakes and steering. But I maintain that it has become so complex that if you screw up one thing the whole thing is messed up. If you want to study a manual and buy a bunch of equipment to find and replace a tiny chip that runs a whole engine.. fine, be my guest. I, for one, and thousands like me will find and take my car to a mechanic who is well trained, studies his craft, and can be trusted to do the job right and not leave me stranded on the turnpike because a chip malfunctioned.

On Apr 12, 2013, at 6:07 AM, Matt Coia wrote:

So, are we talking modifying or maintaining vehicles now? I think the things you talk about are still possible but the number of young folk who would actually WANT to yank their alternator from their car has dwindled. Where the primary interest of the youth in the 50's/60's might have been cars, today we could probably argue that the primary interest of our current youth revolves around computers/gaming/social media. It's a different mindset.




------------------------------

Message: 17
Date: Fri, 12 Apr 2013 08:15:51 -0500
From: Paul Nord <paul.nord@valpo.edu<mailto:paul.nord@valpo.edu>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] sound
Message-ID: <DAC0168C-B8CB-4690-9764-1562199B0FE5@valpo.edu<DAC0168C-B8CB-4690-9764-1562199B0FE5@valpo.edu">mailto:DAC0168C-B8CB-4690-9764-1562199B0FE5@valpo.edu>>
Content-Type: text/plain; charset=us-ascii

Excellent question.

Yes, just as you suspect, there are multiple resonances in the bugle. The resonance which sounds is a function of the driving frequency. This means that such an instrument can only play certain notes of the scale. There may be a small range around those pitches which will sound. But, principally you are limited to those notes because of the fixed length of the instrument. On a valved brass instrument like a trumpet the valves cut off or add lengths of pipe. Each valve position allows a different harmonic series to sound.

See:
Bugle - Wikipedia, the free encyclopedia

And compare those notes which the bugle can play to the melody for Reveille or Taps. These songs are played on just these notes because each is written for the bugle.
Reveille - Wikipedia, the free encyclopedia

Paul


On Apr 12, 2013, at 6:21 AM, "Anthony Lapinski" <Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>> wrote:

Does anyone know how a bugle produces different notes (as it has no keys,
valves, slides, etc.)? I know the instrument when played is physically
closed, but it behaves like an open pipe due to the bell's conical shape.
So the harmonic series is fn = nv/2L The length of the instrument is
constant, so does the player just blow/buzz his/her lips faster? or with a
higher frequency? That changes the harmonics/frequencies, but does that
change v in the equation? I thought v was the speed of sound in air (343
m/s) for brass instruments. I'm a bit confused with some of the finer
details of this "simple" instrument.

_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l



------------------------------

Message: 18
Date: Fri, 12 Apr 2013 10:32:29 -0400
From: "Donald Polvani" <dgpolvani@verizon.net<mailto:dgpolvani@verizon.net>>
To: <Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>>
Subject: Re: [Phys-L] sound
Message-ID: <000601ce378a$8ff25140$afd6f3c0$@verizon.net<mailto:000601ce378a$8ff25140$afd6f3c0$@verizon.net>>
Content-Type: text/plain; charset=US-ASCII

Paul Nord on 4/12/13 at 9:16 am wrote:

" Yes, just as you suspect, there are multiple resonances in the bugle. The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There may
be a small range around those pitches which will sound. But, principally
you are limited to those notes because of the fixed length of the
instrument. On a valved brass instrument like a trumpet the valves cut off
or add lengths of pipe. Each valve position allows a different harmonic
series to sound."

As an old (high school level) trumpet player I can assure you that the
player's lips must vibrate at a higher frequency to achieve higher notes on
a bugle. A trumpet becomes, effectively, a bugle, if the player doesn't
make use of the valves. This is achieved by stretching the muscles around
the lips, compressing the mouthpiece tighter against the player's lips, and
blowing harder. As a high school player limited to producing just a few
notes above "high C", I always admired leading classical trumpet players
like Maurice Andre and Winton Marsalis who could play extremely high notes.
However, even they can be seen to be struggling when producing the highest
possible notes on a trumpet.

Don

Dr. Donald G. Polvani
Adjunct Faculty, Physics
Anne Arundel Community College
Arnold, MD 21012



------------------------------

Message: 19
Date: Fri, 12 Apr 2013 11:14:57 -0400
From: "Anthony Lapinski" <Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] [SPAM] Re: sound
Message-ID: <fc.000f54740994d3f9000f54740994abca.994d52d@pds.org<fc.000f54740994d3f9000f54740994abca.994d52d@pds.org">mailto:fc.000f54740994d3f9000f54740994abca.994d52d@pds.org>>
Content-Type: text/plain; charset=UTF-8

Thanks for these responses. So what, then, changes in the equation fn =
nv/2L? Lips vibrate faster, so v changes? But I thought v = 343 m/s (speed
of sound in air). Or does n change, which creates the higher
frequencies/harmonics? What changes in that equation to predict which
frequencies are played on a bugle or other instrument where L is constant)?

P.S. I was a big fan of Maynard Ferguson, who could hit super high notes
on the trumpet. Saw him live in concert serveal times. Amazing!


Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org> writes:
Paul Nord on 4/12/13 at 9:16 am wrote:

" Yes, just as you suspect, there are multiple resonances in the bugle.
The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There
may
be a small range around those pitches which will sound. But, principally
you are limited to those notes because of the fixed length of the
instrument. On a valved brass instrument like a trumpet the valves cut
off
or add lengths of pipe. Each valve position allows a different harmonic
series to sound."

As an old (high school level) trumpet player I can assure you that the
player's lips must vibrate at a higher frequency to achieve higher notes
on
a bugle. A trumpet becomes, effectively, a bugle, if the player doesn't
make use of the valves. This is achieved by stretching the muscles around
the lips, compressing the mouthpiece tighter against the player's lips,
and
blowing harder. As a high school player limited to producing just a few
notes above "high C", I always admired leading classical trumpet players
like Maurice Andre and Winton Marsalis who could play extremely high
notes.
However, even they can be seen to be struggling when producing the highest
possible notes on a trumpet.

Don

Dr. Donald G. Polvani
Adjunct Faculty, Physics
Anne Arundel Community College
Arnold, MD 21012

_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l




------------------------------

Message: 20
Date: Fri, 12 Apr 2013 10:36:50 -0500
From: Paul Nord <paul.nord@valpo.edu<mailto:paul.nord@valpo.edu>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] sound
Message-ID: <185743B0-1F9E-4643-BAD7-E2524601C67C@valpo.edu<185743B0-1F9E-4643-BAD7-E2524601C67C@valpo.edu">mailto:185743B0-1F9E-4643-BAD7-E2524601C67C@valpo.edu>>
Content-Type: text/plain; charset=us-ascii

Perhaps this is just a question of interpreting that equation.

It might be clearer to write it this way:
f(n) = n*v/(2*L)
where:
n is a positive integer
v is the speed of sound
L is the length of the pipe
f(n) gives you a list of resonant frequencies

As Don points out, you change your embouchure to adjust the driving frequency of your lips. Only when this driving frequency matches one of the resonant frequencies of the pipe will it produce a good sound. There is some feedback from the sound in the pipe which helps to lock in the frequency of your lips. That is to say, you feel your lips buzz against the air column and that helps to cause the flapping of your lips to match a resonant frequency of the pipe.

Paul


On Apr 12, 2013, at 10:14 AM, "Anthony Lapinski" <Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>> wrote:

Thanks for these responses. So what, then, changes in the equation fn =
nv/2L? Lips vibrate faster, so v changes? But I thought v = 343 m/s (speed
of sound in air). Or does n change, which creates the higher
frequencies/harmonics? What changes in that equation to predict which
frequencies are played on a bugle or other instrument where L is constant)?

P.S. I was a big fan of Maynard Ferguson, who could hit super high notes
on the trumpet. Saw him live in concert serveal times. Amazing!


Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org> writes:
Paul Nord on 4/12/13 at 9:16 am wrote:

" Yes, just as you suspect, there are multiple resonances in the bugle.
The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There
may
be a small range around those pitches which will sound. But, principally
you are limited to those notes because of the fixed length of the
instrument. On a valved brass instrument like a trumpet the valves cut
off
or add lengths of pipe. Each valve position allows a different harmonic
series to sound."

As an old (high school level) trumpet player I can assure you that the
player's lips must vibrate at a higher frequency to achieve higher notes
on
a bugle. A trumpet becomes, effectively, a bugle, if the player doesn't
make use of the valves. This is achieved by stretching the muscles around
the lips, compressing the mouthpiece tighter against the player's lips,
and
blowing harder. As a high school player limited to producing just a few
notes above "high C", I always admired leading classical trumpet players
like Maurice Andre and Winton Marsalis who could play extremely high
notes.
However, even they can be seen to be struggling when producing the highest
possible notes on a trumpet.

Don

Dr. Donald G. Polvani
Adjunct Faculty, Physics
Anne Arundel Community College
Arnold, MD 21012

_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l


_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l



------------------------------

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_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l


------------------------------

End of Phys-l Digest, Vol 100, Issue 8
**************************************

---------------------------------
"It is not enough to observe, experiment, theorize, calculate and communicate; we must also argue, criticize, debate, expound, summarize, and otherwise transform the information that we have obtained individually into reliable, well established, public knowledge."
John Ziman

Kyle Forinash
kforinas@ius.edu<mailto:kforinas@ius.edu>
http://homepages.ius.edu/kforinas