High resolution digital is dead. The best DAC's killed it.

Lots of interesting points made on a subject destined to run and run. Last year i was privileged to present the AES Heyser Lecture in Milano (May 2018) which included amongst other topics some discussion and personal reflections on sampling rate conversion. You can (hopefully) access the lecture and some related files via the link below including examples of DSD-to-LPCM conversion using a novel "spectral domain" approach to sampling rate conversion. Unfortunately sound quality on the video is a bit compromised due to a technical recording issue beyond my control. Anyway, I hope the content may prove of interest.
https://www.dropbox.com/sh/nqvvwnlh6n6b98z/AAC6kOb5NT8Gk8pceZSbpl2ha?dl=0
M

this ought to be great, thanks Malcolm!  Downloaded - would not play in browser. I plan to continue my blog @ sonogyresearch.com with some interesting anecdotes from when i liaised to MPEG while working on both contribution quality digital compressed NTSC and HDTV back around 1989-91.  The findings (which can be informally confirmed with any JPEG compression utility and your phone) are very interesting in a world where compression is a dirty word....spoiler alert - compressed HD > uncompressed SD. No surprise if one considers the degree of redundancy in any HD representation.

G

Absolute phase is audible but the majority of listeners are unaware of the phenomenon or have heard it and deemed it insignificant, probably the same ones who can't hear cable differences.

Absolute phase is when the leading pressure wave reaches the listener in the same phase as originally produced. Take for example a spoken word like 'push'. The compressive wave launch will reach the listener and drive his eardrums inwards. A reversed phase will create a rarefaction when it reaches the listeners ears and suck them outwards. Think of a kick drum.


Incorrect phase then means the poor listener is using more mental correction effort to try and add realism on top of all the other reproduction issues where the brain has to try make allowances for background noise, distortion and little or no room treatment etc. Absolute phase is often subtle and occasionally astonishing.
I had my CD collection marked to indicate phase. Lots blank (meaning can't tell a difference) some normal phase and some reverse phase. My Wadia DAC has a phase button which I leave to suit the majority and only occasionally change.

@ geoffkait The effect is not system dependant, it is very real and generally impresses when first noticed. What is system dependant is the extent to which it is heard. The battery test you mentioned works to show the direction of woofer travel. The tweeter will not respond via the XO because its series cap will do its job and block DC which is merely academic because the speaker designer, one has to assume, knew what he was doing and designed for proper phase tracking around the XO frequency. It is not necessary to concern yourselves whether the tweeter is in phase or not. Changing both speaker terminals will invert phase to the speaker XO and the tweeter will follow suit.  2,3 or 4- way speakers same story.

@ erik_squires  Richard Vandersteen's big play is for achieving Time coherence
 which is accomplished by physical driver alignment and in the XO and is one of the best values around. Its the end result. Tweeters or midrange drivers may be connected electrically out of phase to place them acoustically inphase. Polarity is chosen for best performance at XO  Think you mentioned full-range drivers, which operate without any XO as such and have their own special sound but introduce other issues. You mentioned 'non R2R DACs' you were impressed with, care to share.

eric_squires asked:

The modern DAC, the best of them, no longer do this. The Redbook playback is so good high resolution is almost not needed. Anyone else notice this?

Not really. I totally agree that as we solve problems in DACs and in the timing of the signal they are fed, and as recording engineers operate with the systems margins, and as studio formats allow for better filtering, and... (key here - lots of "ands"), we are finding that red book reality is approaching red book theory.

But are today’s DACs, on their own, that much better?  Well, Maybe. I will say that when fed a low-jitter signal, my 20-odd year old Theta DS-Pro (Mike Moffit’s original baby) sounds very, very good. Is it state of the art? No. Is it damn good and better than most modern DACs (which admittedly often cost less?) yes.

First, had a Theta Casanova. WONDERFUL DAC and HT processor.
But .... It sounded a lot better on hi rez than CD.

Modern DACs make it hard to hear the difference I could before. Musically, at 96/24 I might still want the Casanova sound, but at Redbook ......

Best,

E