Since you constantly derail this topic with irrelevant talk, let me instead prove that
1) Olli Niemiatalo's graph *is* equivalent of the spectrum of upsampled white noise. 2) Olli Niemitalo's graph does *not* depict sinc(x)/sinc^2(x). First I'll prove 1). Using palette modification, I extracted the linear interpolation curve from Olli's figure: http://morpheus.spectralhead.com/img/other001b.gif Then I sampled white noise at 500 Hz, and resampled it to 44.1 kHz using linear interpolation. I got this spectrum: http://morpheus.spectralhead.com/img/resampled_noise_spectrum.gif To do a proper A/B comparison between the two spectra, I tried to align and match them as much as possible, and created an animated GIF file that blinks between the two graphs at a 500 ms rate: http://morpheus.spectralhead.com/img/olli_vs_resampled_noise.gif Although the alignment is not 100% exact, to my eyes, they look like totally equivalent graphs. This proves that upsampled white noise has the same spectrum as the graph shown on Olli's graph for linear interpolation. Second, I'll prove 2). Have you actually looked at Olli Niemitalo's graph closely? Here is proof that it is NOT a graph of sinc(x)/sinc^2(x): http://morpheus.spectralhead.com/img/other001-analysis.gif It is NOT sinc(x)/sinc^2(x), and you're blind as a bat if you do not see that. Since I proved both 1) and 2), it is totally irrelevant what you say, because none of what you could ever say would disprove this. Sinc(x) does not have a jagged/noisy look, therefore it is 100% certain it is not what you see on Olli's graph. Point proven, end of discussion. -P _______________________________________________ music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
