From: mcmurtrie@pixelmemory.us   
      
   In article ,   
    Randy Yates  wrote:   
      
   > An open-circuit, class D amplifier output has extremely sharp   
   > edges due to the switching of the bridge. The expectation is that,   
   > somehow, the output is averaged over at least one cycle of the switching   
   > period to form a continuous, analog voltage.   
   >   
   > If this output is connected to a speaker with a mechanical lowpass   
   > characteristic, then the speaker's mass will effectively average   
   > the "digital" output into a continous position.   
   >   
   > Thus my question is, when connecting a class D output to a speaker,   
   > why do we need filtering at all? That is, why wouldn't the mechanical   
   > lowpass filtering of the speaker be sufficient?   
      
   Self-contained systems, like cellphones, don't always have filtering on   
   Class D amps.  In those cases the speaker is guaranteed to have short   
   wires, high impedance, low capacitance, and not be paired with any kind   
   tonal or impedance compensation.   
   --   
   I will not see posts or email from Google because I must filter them as spam   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)