jkeny wrote: > Right, so your statement "No DAC playing back 176.4kHz should touch the > audible band " was meaningless to this test & only confuses matters. A > minimum phase filter > > Let's see what Archimago did then - *"I took ~1 minute of these three > 24/44 or 16/44 recordings and using SoX, upsampled them to 24/176.4 with > either the linear or minimum phase upsampling algorithm, re-naming one > file A and another B." * > > So he used an upsampling algorithm of either minimum or linear phase to > bring these files to 24/176. Now tell me how pre-ringing at the Nyquist > frequency of 88KHz is of interest to anyone & what this test is intended > to do?
Julf wrote: > Seems you don't really understand the Gibbs effect either. >From what I can see, http://archimago.blogspot.com/2015/04/internet-blind-test-linear-vs-minimum.html pretty well answered jkeny's question: "As you can see by the images above, when we send a 16/44 "impulse" through these reconstruction filters, we create different forms of high-frequency ringing. Linear phase filters do not result in phase distortion. However, the "issue" we are to note looking at the typical linear phase impulse response is the symmetrical ringing as seen above. It has been suggested that the pre-ringing ("pre-echo") is damaging to the sound and "unnatural". As a result, minimum phase filter algorithms became staples of companies like the aforementioned Meridian and later on Ayre with their well known whitepaper on their filter choice (I see this is also used in the recent PonoPlayer). Realize however that in removing the pre-echo, minimum phase filters will result in high frequency phase shift compared to the linear phase filter as shown here (from the Infinite Wave website looking at SoX 14.4 VHQ Minimum Phase vs. Linear phase):" Perhaps we should ask a question that a reasonable person who knew very little about digital technology could still answer, such as "What is unclear about the above paragraph"? ------------------------------------------------------------------------ arnyk's Profile: http://forums.slimdevices.com/member.php?userid=64365 View this thread: http://forums.slimdevices.com/showthread.php?t=103537 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
