In Reply to: MQA Loses Part of Spectrum on Some Tracks? posted by Charles Hansen on May 29, 2017 at 23:23:05:
This is a 44.1/24 recording. The gap seems centered on the Nyquist frequency. The original recording had a sharp roll-off--I know this because I measured it myself (see attached; one is the original CD. The other is MQA.). MQA has a slow roll-off filter, so it passes aliased content above the symmetric gap. I've got no idea what the bump is in that spectrum, between 40 and 45 kHz; I don't see it in mine.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Charles, Please tell me if this makes sense. - Jim Austin 20:21:45 05/31/17 (25)
- To clarify ... - Jim Austin 13:06:30 06/05/17 (14)
- Something seems very wrong here - Charles Hansen 16:06:39 06/05/17 (13)
- RE: Something seems very wrong here - Jim Austin 18:08:50 06/05/17 (12)
- Hmmm... - Charles Hansen 19:31:32 06/05/17 (11)
- RE: Hmmm... - Jim Austin 19:37:30 06/05/17 (10)
- Something still seems wrong here - Charles Hansen 22:40:21 06/05/17 (9)
- Let's go back to Beyonce - Jim Austin 07:47:16 06/06/17 (8)
- OK, now we are on the same page - it is aliasing *and* it is a bug. - Charles Hansen 13:47:03 06/06/17 (7)
- On a different, yet related topic - Charles Hansen 14:54:02 06/06/17 (0)
- RE: OK, now we are on the same page - it is aliasing *and* it is a bug. - Jim Austin 14:34:09 06/06/17 (5)
- Aha! - Charles Hansen 19:01:41 06/06/17 (4)
- Interesting - Jim Austin 19:22:14 06/06/17 (3)
- Agreed - very interesting! - Charles Hansen 22:08:13 06/06/17 (2)
- RE: Agreed - very interesting! - Jim Austin 04:50:06 06/07/17 (1)
- Thanks - Charles Hansen 12:42:23 06/07/17 (0)
- RE: Charles, Please tell me if this makes sense. - Charles Hansen 23:59:31 05/31/17 (9)
- P.S. - Jim Austin 05:03:44 06/01/17 (6)
- Now I think we are getting somewhere - Charles Hansen 15:17:11 06/01/17 (5)
- RE: Now I think we are getting somewhere - Jim Austin 15:35:36 06/01/17 (4)
- Then I am really confused... - Charles Hansen 19:25:53 06/02/17 (3)
- RE: Then I am really confused... - Fitzcaraldo215 13:27:43 06/03/17 (1)
- RE: Then I am really confused... - Charles Hansen 21:34:02 06/03/17 (0)
- Correction - Charles Hansen 03:27:37 06/03/17 (0)
- RE: Charles, Please tell me if this makes sense. - Jim Austin 04:53:40 06/01/17 (1)
- RE: Charles, Please tell me if this makes sense. - John Atkinson 20:07:59 06/02/17 (0)