Home Critic's Corner

Discuss a review. Provide constructive feedback. Talk to the industry.

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Critic's Corner ] [ Return to Search Results ]
[ Alert Moderator ]

RE: To me, Sue, high-end, can only be about coherent 3D recordings of acoustic music.

> > I am performing an appropriate test myself and will report my findings.

> Interested in those test.

Bob Carver claimed that the MQA files sent to writers had been processed with
something like his Sonic Holography circuit. This circuit is basically
a Blumlein "shuffler," which splits the stereo audio signal into its Sum
and Difference components, applies gain and/or EQ to the Difference
component, then recombines the Sum and Difference components into Left and
Right signals. (See my review of the BSG Signal Completion Stage linked below
for an examination of how this is done.)

So, if Carver's claim is correct, then examining the Difference between the
two channels of an MQA file and the PCM original will reveal if any "shuffling"
had been done.

I took 3 recordings for which I had both the originals and the MQA versions
that I had used for my initial auditioning of MQA back in 2016 where I had
found the MQA version to sound superior: a track from Keith Jarrett's
Cologne Concert, a Debussy prelude, and one of my choral recordings with
the Portland State Chamber Choir.

Extracting the difference information for the PCM originals was straightforward.
For the MQA versions, I decoded the files with Roon feeding my PS Audio DAC
and and digitized the PS Audio's analog out with an Ayre A/D converter operating
at 24 bits and 192kHz sample rate. I adjusted the peak levels of the resultant files
to match those of the original PCM files and extracted the channel difference
information.

In all 3 cases, the channel-difference file of the MQA version had the same
peak level as that of the original PCM file, as well as virtually identical spectra.
So Bob Carver was wrong. As I said before.

John Atkinson
Technical Editor, Stereophile

This post is made possible by the generous support of people like you and our sponsors:
  Parts Connexion  

Follow Ups Full Thread
Follow Ups
FAQ

Post a Message!

 Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]