In Reply to: another interesting test posted by Werner on July 29, 2009 at 22:45:55:
"Did you use MP twice?"
No. Just once. As you said, it is only needed once. It can be either in the anti-alias case or in the anti-image case. Not only is this supported by theory, it is supported by the practical reality of the sampling rate converter that I used as seen in waveforms. (Izotope RX Advanced allows you to pick any mixture of minimum phase to linear phase. I just tried the limits for the tests.)
The need for MP filters in a playback system is an indication that the mastering engineer lacked the proper tools or used them improperly. The cultural artifact he produces is a set of numbers that represents a continuous analog waveform interpreted according to the sinc function, and this should have been explicitly specified in the Red Book standard if it wasn't. If a consumer uses playback that is intentionally different from the best available approximation to the sinc function then he is choosing to use a subtle "tone control". Nothing wrong with this, if it makes your recordings sound better, but if you are creating recordings, as I am, then it is necessary to have the least colored playback possible.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: another interesting test - Tony Lauck 07/30/0907:16:45 07/30/09 (0)