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Hi<br>
the papers on <a moz-do-not-send="true"
href="http://www.klippel.de/pubs/papers.asp">http://www.klippel.de/pubs/papers.asp</a>
where quiet interesting. But the page went down. <br>
It looks like it went to:
<a class="moz-txt-link-freetext" href="http://www.klippel.de/nc/know-how/literature/papers.html?sword_list">http://www.klippel.de/nc/know-how/literature/papers.html?sword_list</a>[0]=paper&sword_list[1]=speaker<br>
<br>
Greetings<br>
<br>
Am 16.10.2010 06:46, schrieb Martin Schied:
<blockquote cite="mid:4CB92E40.2030108@gmx.net" type="cite">
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charset=ISO-8859-1">
Hi!<br>
<br>
I'm no speaker modeling expert at all, but I can try to describe
what produces sounds in an overloaded speaker. There are various
sources of distortion, symmetrical (mechanic suspension) and
asymmetrical (magnetic field) and also time variant (temperature)
and modulation (doppler effect / amplitude modulation) effects. I
don't know which effects have a stronger or weaker influence, but
I describe what I imagine:<br>
<br>
<br>
High peak amplitude, positive wave:<br>
<br>
speaker moves to the front, parts of the coil will not be in the
magnetic field anymore. The field isn't zero outside the magnet
gap, but I guess it decreases rapidly and is almost zero (so for
example if half the coil is inside the magnet, the parts outside
will not produce a force. So the force is only half as strong as
it should. For simplicity you could say the field outside the
magnet's gap is zero, so you have a linear function of excitation
/ current. Also If the coil moves out of the field its impedance
will decrease which has influence on frequency response for higher
frequencies a bit.<br>
<br>
Heat<br>
<br>
If the impedance is reduced as described above, a higher current
will flow and heat the coil more than usual. The resistance of the
coil will increase when it gets warmed and thus the efficiency of
the speaker decreases (up to -7 dB I read somewhere, but this
wasn't meant for almost dead speakers but heavy load). The heat
needs some time to dissipate, so some kind of slow pumping
compression effect occurs.<br>
<br>
High amplitude, negative wave:<br>
<br>
The speaker's coil might crash into the magnet and create
different mechanical noises. Also the speakers diaphragm will be
deformed by this crash and create various kinds of noise.
Additionally it carries the noises the coil created - depending on
the material and shape this sound different (paper, Kevlar,
aluminum, etc sound different). If this crash doesn't occur
(professional speakers don't have this issue usually) the negative
wave will not be distorted too much and maybe distortion can be
ignored.<br>
<br>
In both directions the spider (basically a spring) starts to
become nonlinear. Different manufacturers have different curves,
but for small amplitudes they all pretend to be linear - so some
experiments with sin~ or tanh~ might do it here.<br>
<br>
Then generally there are happening doppler-effects on all speakers
with big excursion. You could model them through a variable delay,
modulated by a differentiated, low pass filtered signal (don't
bite if I'm wrong, it's already very late... ). Amplitude
modulation can be applied the same way (lowpass and apply it to
higher frequencies).<br>
<br>
so to sum it up:<br>
<br>
apply symmetric distortion for the spider, split the path into
positive and negative parts, for positive samples: tanh~,
polynomials or other wave shapers, for negative parts let the
signal untouched or add noises of a crashing coil (don't know how
to achieve this), then sum both signals up, apply doppler effect,
amplitude modulation and pumping compression. perhaps that sounds
like your speakers then :)<br>
<br>
I'm not sure if this works at all, but it definitely will sound
very distorted in the end.<br>
<br>
did you already discover <a moz-do-not-send="true"
href="http://www.klippel.de/pubs/papers.asp">http://www.klippel.de/pubs/papers.asp</a>
?<br>
<br>
<br>
<br>
cheers<br>
Martin<br>
<br>
<br>
On 15.10.2010 21:10, - wrote:
<blockquote cite="mid:4CB8A735.90506@gmx.de" type="cite">
<pre>Thank you for your answer,
but as I wrote I don't want the sound of simple clipping like clip~,
tanh~ or overdrive~. I want the sound of a speaker crying for mercy
because you put just too much through it.
But I don't know where to start. I know there are complex distortion
effects, which are able to simulate different speaker cabinets after
variable amps recorded by different microphones. But they all cost big
money. Also I don't need the physical simulation. I just want the sound.
If you want I can try to record the sound I'm talking about.
I tried to search for information how to do this but couldn't find
anything usable. Not even an analysis what happens inside the speaker
when you torture it like this.
I already know the forum but don't want to doublepost. I really liked
the post about the oto biscuit. Neat distortion possibility's.
Am 15.10.2010 17:12, schrieb George Ker:
</pre>
<blockquote type="cite">
<pre>Hello,
I can't really understand, so , you mean something different from
</pre>
</blockquote>
<pre>[clip~] ?
</pre>
<blockquote type="cite">
<pre>I' m sure you can find really good patches in the puredata.hurleur.com
</pre>
</blockquote>
<pre>forum searching about distortion , overdrive clip etc
</pre>
<blockquote type="cite">
<pre>-----
GeorgeKer~
<a moz-do-not-send="true" href="http://tinyurl.com/georgeker">http://tinyurl.com/georgeker</a>
-----
On 14 October 2010 23:19, - <a moz-do-not-send="true" href="mailto:fallen_devil@gmx.de"><fallen_devil@gmx.de></a> wrote:
Hi,
does anyone know how to simulate the sound of an overdriven
</pre>
</blockquote>
<pre>speaker? You
</pre>
<blockquote type="cite">
<pre> know the crunchy sound when you torture it with a strong bass. It's
nowhere near the sound of an normal overdrive with some kind of
</pre>
</blockquote>
<pre>clipping.
</pre>
<blockquote type="cite">
<pre> Greetings
-
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</pre>
<blockquote type="cite">
<pre> </pre>
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