[squeak-dev] Inquiry: Etoy (or other) Projects in Physics (specifically acoustics)

Hi All,

I'm looking for a demonstration about acoustics. This would be for a
college-level beginning class. I doubt that one exists, but I thought
that maybe I could start with a physics project (or any code, if you
have it) to get an idea of how to create/modify for acoustics
demonstrations.

Any ideas most welcome!

Thanks much!

brad

--
Brad Fuller
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Hi Brad,


BF> I'm looking for a demonstration about acoustics. This would be for a
BF> college-level beginning class. I doubt that one exists, but I thought

for building yet another cardioid bass speaker I did some interference
simulation.

After some fiddling with the phase of the rear speaker i get contour
plots like attached. Now the project is matlabized.

With just inverting rear phase it makes for more interesting display.

Next week I'm at the customer so if you're interested I can ask if I
can release some of it.


Cheers,

Herbert                            mailto:[hidden email]

Herbert König wrote:
> Next week I'm at the customer so if you're interested I can ask if I
> can release some of it.

Please do! This looks very cool. I'd like to play with it myself.

Cheers,
   - Andreas

AR> Please do! This looks very cool. I'd like to play with it myself.

I'll let you know.

Herbert                            mailto:[hidden email]

At Mon, 10 Aug 2009 21:07:46 -0700,
Brad Fuller wrote:
  I once was writing a version of distance measuring
(http://wiki.laptop.org/go/Acoustic_Tape_Measure and some discussion
on it at: http://dev.laptop.org/ticket/5202) by using the spectrum
analyzer.  I don't think I have the working project but just a
thought...

-- Yoshiki

On Tue, Aug 11, 2009 at 12:21 AM, Andreas Raab<[hidden email]> wrote:
> Herbert König wrote:
>>
>> Next week I'm at the customer so if you're interested I can ask if I
>> can release some of it.
>
> Please do! This looks very cool. I'd like to play with it myself.


ditto!


--
Brad Fuller
                   *NOTE NEW PHONE*
                     +1 (408) 335-0112

On Tue, Aug 11, 2009 at 7:39 AM, Yoshiki Ohshima<[hidden email]> wrote:
that is an interesting idea.



--
Brad Fuller
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On Mon, Aug 10, 2009 at 9:07 PM, Brad Fuller<[hidden email]> wrote:
> Hi All,
>
> I'm looking for a demonstration about acoustics. This would be for a
> college-level beginning class. I doubt that one exists, but I thought
> that maybe I could start with a physics project (or any code, if you
> have it) to get an idea of how to create/modify for acoustics
> demonstrations.
>

The examples could be as crude as vibrations of strings, springs and
simple harmonic motion. (Pipes and cavities are a plus.)

Hi,

AR>> Please do! This looks very cool. I'd like to play with it myself.
HK> I'll let you know.
finally found the time to prepare it a bit.

So this is a dipole radiator simulation. A dipole radiator comprises two
speakers driven at so low frequencies that they act as point sources
without directivity.

The model calculates the interference of the two sound waves depending
on direction and frequency. Both speakers are assumed to radiate the
same frequencies.

To support it a bit there are the classes "SignalPlotter" expanding
on some test method in FFT and a logarithmic scale morph subclassed
from ScaleMorph.

All classes have comments and examples on the class side and you can
ask me. SignalPlotter's class side sampleContourPlot is the most
illustrative example.

I did it in 3.8.2 and tested in 3.10.2.

BTW it's even more fun doing this in reality but complicated to
understand if you don't have enough space around.


Cheers,

Herbert                            mailto:[hidden email]