adamdea;656159 Wrote: > I think we are in agreement- it's just the expression "brick wall"- I > understadn this to mean a filter with effectively no transitional band > ie one which provides infinite attentuation at the transition between > the pass band and the stop band. Sorry, I didn't intend the term "brick-wall" to mean a filter of infinite slope, but rather a very high-order filter that attenuates rapidly.
adamdea;656159 Wrote: > In practice this may mean something with really steep attenuation at the > transition. This is really difficult to do in analog but is trivial in > the digital domain because all you have to do is to calculate the > values that the samples would have had *if* a perfect analog filter > existed. Quite so. BUT... the effect of a digital filter on the signal is the same as that of a perfect analogue filter of the same order. Of course there is no such thing as a perfect analogue filter - component tolerances and such like ensure that - so a digital filter will certainly be better than the equivalent analogue one. But digital filters still create artefacts in the passband; they are not magic. adamdea;656159 Wrote: > I guess this comes back to your point that even a digital brick-wall > filter has some (perceptible) phase effect. Actually my point is that while a digital brick-wall filter *does* have some (measurable) phase effect, it's probably not *perceptible*. adamdea;656159 Wrote: > if that's right then I agree that there would be an advantage in having > a final product with fs > 44.1kHz (but >96kHz?) I remain sceptical that >44.1/48kHz is necessary. As for those who insist they need >96kHz - they are clearly ready to be taken away in jackets with very long sleeves. -- cliveb Transporter -> ATC SCM100A ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=89733 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
