[sdiy] Experiment with bandlimited ramps

[Scott Gravenhorst]

Tom Wiltshire <tom at electricdruid.net> wrote:
>Hi All,
>
>I've done some experiments generating bandlimited ramp waves at  
>various frequencies and with various numbers of harmonics. The  
>results (lots of sound files - page loads fairly slowly) are at:
>
>http://www.electricdruid.com/index.php?page=thoughts.bandlimited
>
>The idea was to find out practically how many harmonics are required  
>for an accurate additive synthesis. Since by the time you're at a  
>5KHz fundamental, you'd be lucky to hear the 5th harmonic, I started  
>at about 85Hz. These low notes need the most harmonics to sound good.
>
>Have a listen and see what you think.
>

When I listen to the aiff files with Windows Media Player grabs the file and plays
it as well as displays the waveform.  (Quicktime for Windows does wierd things to
my systems)  The non-octave samples all look like clipped sinewaves for the most
part.  The OCT sounds look similar, with a glitch pulse included in the clipped
portion of the positive peak.  The OCT2 sounds look more like a band limited ramp,
but with some distortion included that I can't visually identify.

Is this simply a problem with the WMP9 waveform display? i.e., is the sound OK? 
For what it is worth, I've done lots of DAC listening myself to sounds I've made
here - but they are wav files, not aiff.  The wavs look as they should.  Soooo I'm
wondering if WMP9 plays aiff correctly and displays incorrectly?  Or is it barfing
both?

Can anyone confirm or deny?  I'm using WinXP SP2 with Windows Media Player 9.

-- ScottG
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-- Scott Gravenhorst
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