[sdiy] Harmonic bandwidth

[Donald Tillman]

   > Date: Wed, 09 Jan 2008 09:45:33 -0700
   > From: Ian Fritz <ijfritz at comcast.net>
   > 
   > Speaker dynamics: If you put a perfect sawtooth into a speaker
   > you would be asking for its displacement to change
   > instantaneously.  If you rephased the harmonics then you would no
   > longer have this step.  Of course you never have exactly this
   > situation, but the transient mechanical response of the speaker
   > to a step should be kept in mind.  For this reason I think the
   > sawtooth does not make a very good test.

Hey Ian,

Not exactly; a speaker cone's acceleration is proportional to the
input signal voltage.  So the displacement is two integrals away and
won't be changing instantaenously.

I actually think a sawtooth wave is pretty good; look what happens to
a square wave when you throw it through a hilbert transform (constant
90-degree phase shift, huge spikes).

  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com