trumpet acoustics

Joseph and all,

While meandering in the "links" section I found a link of
Paul's that linked to this page...

http://www.phys.unsw.edu.au/~jw/brassacoustics.html

...which has tons of great information and many awesome
sound examples.

-Carl

--- In tuning@yahoogroups.com, Carl Lumma <ekin@l...> wrote:

/tuning/topicId_51932.html#51932

> Joseph and all,
>
> While meandering in the "links" section I found a link of
> Paul's that linked to this page...
>
> http://www.phys.unsw.edu.au/~jw/brassacoustics.html
>
> ...which has tons of great information and many awesome
> sound examples.
>
> -Carl

***Thanks so much for this link, Carl. It was particularly
interesting, of course, since I'm writing for trumpet again. Good
explanation of how the "pedal tones" that Klaus mentioned are done...

Say, I have a general question regarding the harmonic series that I
was thinking about when reading this.

Let's say we take a simple example: a guitar string.

Now we have our finger going up and down and we find a harmonic
series.

Of course the harmonic series is logarithmic so the lengths of guitar
string keep getting shorter and shorter as we approach the *next*
harmonic, even though the multiplication is *equal* (i.e. 1x, 2x, 3x,
4x, 5x, 6x, 7x...etc.)

It was stated that this was because of the nature of the way the ear
hears...

So the question is: are harmonics actually a *physical* phenominon
or are they something that is "manufactured" in the way the ear
hears? So, in other words, is there a special resonance all the way
linearly up and down the string that we just aren't hearing, and we
only hear a harmonic *node* because of the ear??

I guess this is confusing me a bit...

Thanks!

JP

--- In tuning@yahoogroups.com, "Joseph Pehrson" <jpehrson@r...> wrote:
> --- In tuning@yahoogroups.com, Carl Lumma <ekin@l...> wrote:
>
> /tuning/topicId_51932.html#51932
>
> > Joseph and all,
> >
> > While meandering in the "links" section I found a link of
> > Paul's that linked to this page...
> >
> > http://www.phys.unsw.edu.au/~jw/brassacoustics.html
> >
> > ...which has tons of great information and many awesome
> > sound examples.
> >
> > -Carl
>
> ***Thanks so much for this link, Carl.

The "root directory" of that page is highly recommended if you're
interested in these topics.

> It was particularly
> interesting, of course, since I'm writing for trumpet again. Good
> explanation of how the "pedal tones" that Klaus mentioned are
done...

Yup . . . it's possible to use the same phenomenon to lock into
a "half-integer" or "third-integer" frequency as well -- for example,
you can play 5/2*f with your lips (though it's hard) because all its
even harmonics will line up with resonances, so mode-locking can take
place, if weakly.

> Say, I have a general question regarding the harmonic series that I
> was thinking about when reading this.

You've come to the right place ;)

> Let's say we take a simple example: a guitar string.
>
> Now we have our finger going up and down and we find a harmonic
> series.
>
> Of course the harmonic series is logarithmic so the lengths of
guitar
> string keep getting shorter

Not quite right. The harmonic series is *proportional* to frequency,
while string length is *inversely proportional* to frequency.
Logarithms don't come into play here.

> and shorter as we approach the *next*
> harmonic, even though the multiplication is *equal* (i.e. 1x, 2x,
3x,
> 4x, 5x, 6x, 7x...etc.)

Yes, because in terms of positions on the string, these translate
into 1, 1/2, 1/3, 1/4, 1/5, 1/6, 1/7 . . .

> It was stated that this was because of the nature of the way the
ear
> hears...

The interval that we *hear* between adjacent harmonics *does* get
shorter, and that *is* logarithmic, unlike the above. This is, pretty
much, the nature of how we hear, and makes some sense, considering
that it allows a human voice to "sound the same" regardless of
whether it is producing a high or low tone -- the intervals in the
spectrum never change.

> So the question is: are harmonics actually a *physical* phenominon
> or are they something that is "manufactured" in the way the ear
> hears? So, in other words, is there a special resonance all the
way
> linearly up and down the string that we just aren't hearing, and we
> only hear a harmonic *node* because of the ear??

I'm afraid I can't even understand this question . . . maybe you can
expand on it for me? Or maybe the above already clarified it . . .

>Yup . . . it's possible to use the same phenomenon to lock into
>a "half-integer" or "third-integer" frequency as well -- for example,
>you can play 5/2*f with your lips (though it's hard)

It's not that hard with a mouthpiece. Just lips, I think I can do it,
but I can't test it just now as my neighbors are sleeping.

-Carl

--- In tuning@yahoogroups.com, Carl Lumma <ekin@l...> wrote:

> >Yup . . . it's possible to use the same phenomenon to lock into
> >a "half-integer" or "third-integer" frequency as well -- for
example,
> >you can play 5/2*f with your lips (though it's hard)
>
> It's not that hard with a mouthpiece.

What do you mean? With just a mouthpiece, there's no such thing
as 'f', so this doesn't even make sense.

> Just lips, I think I can do it,
> but I can't test it just now as my neighbors are sleeping.

Likewise.

>> >Yup . . . it's possible to use the same phenomenon to lock into
>> >a "half-integer" or "third-integer" frequency as well -- for
>> >example, you can play 5/2*f with your lips (though it's hard)
>>
>> It's not that hard with a mouthpiece.
>
>What do you mean? With just a mouthpiece, there's no such thing
>as 'f', so this doesn't even make sense.

It's called "buzzing" and it definitely has a pitch. I didn't
read the Australian page but I thought I saw some mention of
how the mouthpiece alone and even the vocal tract of the player
(esp. re. didge.) have some impedance or something.

-Carl

--- In tuning@yahoogroups.com, Carl Lumma <ekin@l...> wrote:

> >> >Yup . . . it's possible to use the same phenomenon to lock into
> >> >a "half-integer" or "third-integer" frequency as well -- for
> >> >example, you can play 5/2*f with your lips (though it's hard)

I see I was unclear here. I shouldn't have said "with your lips".

> >> It's not that hard with a mouthpiece.
> >
> >What do you mean? With just a mouthpiece, there's no such thing
> >as 'f', so this doesn't even make sense.
>
> It's called "buzzing" and it definitely has a pitch.

Of course, but there's no resonant frequency (unless it's extremely
high, and 5/2 times that would be even higher) that guides this pitch
into a specific location -- you can just as easily buzz at any pitch
you want.

>> It's called "buzzing" and it definitely has a pitch.
>
>Of course, but there's no resonant frequency (unless it's extremely
>high, and 5/2 times that would be even higher) that guides this pitch
>into a specific location -- you can just as easily buzz at any pitch
>you want.

Yes.

-Carl

--- In tuning@yahoogroups.com, "wallyesterpaulrus" <paul@s...> wrote:

/tuning/topicId_51932.html#51963

>
> I'm afraid I can't even understand this question . . . maybe you
can
> expand on it for me? Or maybe the above already clarified it . . .

***I guess what I mean is that one would *expect* harmonics that are
2x, 3x, 4x, 5x, 6x, 7x the fundamental to be "equal" multiples of the
fundamental in pitch space, as in "octaves..." but they *aren't*
because of the logarithmic nature of hearing and they get closer and
closer to one another in frequency as one goes up the series...

(??)

JP

--- In tuning@yahoogroups.com, "Joseph Pehrson" <jpehrson@r...> wrote:
> --- In tuning@yahoogroups.com, "wallyesterpaulrus" <paul@s...> wrote:
>
> /tuning/topicId_51932.html#51963
>
> >
> > I'm afraid I can't even understand this question . . . maybe you
> can
> > expand on it for me? Or maybe the above already clarified it . . .
>
> ***I guess what I mean is that one would *expect* harmonics that are
> 2x, 3x, 4x, 5x, 6x, 7x the fundamental to be "equal" multiples of the
> fundamental in pitch space, as in "octaves..." but they *aren't*
> because of the logarithmic nature of hearing and they get closer and
> closer to one another in frequency as one goes up the series...

Right -- umm . . . they don't get closer to one another in frequency,
of course, but because of the logarthmic nature of hearing, they get
closer and closer in *perceived pitch* . . . clear now?

>
> (??)
>
> JP

--- In tuning@yahoogroups.com, "wallyesterpaulrus" <paul@s...> wrote:

/tuning/topicId_51932.html#51999

> --- In tuning@yahoogroups.com, "Joseph Pehrson" <jpehrson@r...>
wrote:
> > --- In tuning@yahoogroups.com, "wallyesterpaulrus" <paul@s...>
wrote:
> >
> > /tuning/topicId_51932.html#51963
> >
> > >
> > > I'm afraid I can't even understand this question . . . maybe
you
> > can
> > > expand on it for me? Or maybe the above already clarified
it . . .
> >
> > ***I guess what I mean is that one would *expect* harmonics that
are
> > 2x, 3x, 4x, 5x, 6x, 7x the fundamental to be "equal" multiples of
the
> > fundamental in pitch space, as in "octaves..." but they *aren't*
> > because of the logarithmic nature of hearing and they get closer
and
> > closer to one another in frequency as one goes up the series...
>
> Right -- umm . . . they don't get closer to one another in
frequency,
> of course, but because of the logarthmic nature of hearing, they get
> closer and closer in *perceived pitch* . . . clear now?
>

***Yes, thanks!

JP