QUOTE(AndyH-ha @ Sep 2 2006, 20:37)

Rockfan posted some images of "stair step waveforms." I am curious about how you obtained them. Most audio editors show a realistic representation of what actually comes out of a DAC which, for a continuous sine wave tone, is a smooth sine wave. They will not produce such a "stair step" display. What program does?
For gawd's sake.
Look, those are screen grabs from zooms of high frequency sines, or rather, sines quantized with 16/44 PCM (from good-old Goldwave).
At 18, 20, and 21KHz, to be precise, as clearly stated in the post.
Before someone starts droning on about how "you can't hear that high, so they're irrelevent", they are nonetheless well inside the touted bandwidth of CD.
The "stairs" are invididual samples, that is to say, they represent 1/44100th of a second , exactly as you will see in the vast majority of audio editors, and in fact of the
actual waveform prior to digital filtering.
Let me repeat, for your and everyone elses' benefit THIS IS EXACTLY HOW THESE FREQUENCIES ARE QUANTIZED AT 16/44, AND PRECISLY MIMIC WHAT ONE WOULD FIND IF CAPTURING A REAL-WORLD SINE WITH A 16/44 A/D CONVERTOR.
Do have to remind everyone here what
aliasing is?
I find it incredible that I'm having to make these statements at all.