Is lower jitter better than lower beta and C1?

vbimport

#1

I just ran some tests on some T-Y media that I use for audio CDs. Using PlexTools Professional XL. Burner is my Premium2, FW v. 1.03. Ran burns at various speeds and settled on 8x and 16x as they seem to produce the best looking data. PowerRec is on.

What I wanted to know is whether, for the best audio possible, a slightly better looking jitter spectrum is better than fewer C1 errors and a slightly better beta. I have to get a web-enabled photo capability in order to post the scan pics. Yes, I’m in the dark ages.


#2

Unless the jitter, BLER or beta is out of spec and the drive’s error correction kicks in, there shouldn’t be any impact on audio quality at all, as audio CDs are a digital means of storage.


#3

What’s not clear with the PlexTools jitter assessment method is just what constitutes “out of spec”. And for those of us using a separate transport and DAC (especially if the data is not being reclocked) the level of jitter in the disc may be worth trying to minimize. I’m looking to understand what the balance and tradeoff is.


#4

[QUOTE=tony22;2622353] I have to get a web-enabled photo capability in order to post the scan pics.[/QUOTE]Not needed. See my signature for details :slight_smile:

Michael


#5

There are a couple of things to bear in mind:

Plextor drives don’t report absolute jitter, only the relative level across the disc. So one cannot compare the jitter level of different discs using a Plextor drive. The only consumer drives that can report jitter using an absolute scale are Nexperia-based Benq DVD writers (or [U]some[/U] early Lite-On CD writers). Production of the Benq drives ceased over 5 years ago.

As [B][I]kg_evilboy[/I][/B] has already mentioned, because the audio has been digitally encoded reducing the jitter level will not affect the sound quality at all. Some CD players have difficulty reading discs with high jitter, so it can affect the ‘playability’ of the disc and may increase the chance of a CD player encountering an uncorrectable error.

But the whole question of ‘sound quality’ is irrelevant to CD writing. Unless the drive playing the CD encounters an uncorrectable error (or has an inconsistent read offset) the audio data read will be the same.

There are two levels of error correction on audio CDs. An uncorrectable error is ≥3 bytes at the second level of correction, normally referred to as an E32 error (in PlexTools CU). Remember that these are errors reported by the drive, not errors which exist on the disc as such. Another drive reading the same disc may encounter more or fewer errors.


#6

As you are running a Premium 2 and are after the best audio recording, would it not be better to use the AMQR (Audio Master Quality Recording) system built into the drive and Plextools ?


#7

[QUOTE=Sonic2171;2622461]As you are running a Premium 2 and are after the best audio recording, would it not be better to use the AMQR (Audio Master Quality Recording) system built into the drive and Plextools ?[/QUOTE]

I thought AMQR burned discs were known to sometimes not work in audio transports.


#8

AMQR increases the pit/land length (the same effect using GigaRec <1). It may improve readability in some CD players, or it may have the opposite effect. It will of course make no difference to the sound quality.

One can prove that none of these factors affect the sound quality by comparing the CRC of audio extracted from the discs (remembering that different drives have different read & write offsets).


#9

[QUOTE=tony22;2622545]I thought AMQR burned discs were known to sometimes not work in audio transports.[/QUOTE]

This is true for computer drives, but most dedicated audio transports should not have a problem.
My AMQR/GigaRec discs play in every audio player I have tried them with. :iagree:


#10

[QUOTE=Sonic2171;2622724]This is true for computer drives, but most dedicated audio transports should not have a problem.
My AMQR/GigaRec discs play in every audio player I have tried them with. :iagree:[/QUOTE]
Same here :cool:


#11

[QUOTE=Ibex;2622392]
As [B][I]kg_evilboy[/I][/B] has already mentioned, because the audio has been digitally encoded reducing the jitter level will not affect the sound quality at all. Some CD players have difficulty reading discs with high jitter, so it can affect the ‘playability’ of the disc and may increase the chance of a CD player encountering an uncorrectable error.

But the whole question of ‘sound quality’ is irrelevant to CD writing. Unless the drive playing the CD encounters an uncorrectable error (or has an inconsistent read offset) the audio data read will be the same.
[/QUOTE]

While this is true in theory, in practice there may be differences in sound quality with poorly designed CD players. These poorly designed players are surprisingly common and they allow the signals from the player’s digital control system to interfere with the analogue audio part of the player.

I have a Philips CD player that exhibits this effect - there is a slight blurring of the sound when it plays a CD-R of a commercial CD when compared to the original CD (which were checked to be data identical).

James.


#12

There isn’t subject to doubt that different CD-R copies (and CD presses!) on particular CD-systems (not computer cd-roms) can sound different.
There are a lot of attempts to explain reasons of that.
Specifically on topic:
Being based on the numerous post on this question in different forums all over the world it is possible to argue, NOBODY but you own ears can answer which combination of specific media + specific writer + specific writing speed/GigaRec + specific player/transport+DAC is the best.
But solution is quite simple: record some copies of your favorite album (which SOUNDING you know very well) in different record modes and select that, YOU LIKE AURALLY best of all. If you don’t hear the differance - stop worry about jitter and betta.

“Directly or indirectly, but all questions associated with sound have to be resolved by ear as an organ of hearing: the conclusions given by ear are necessary to be challenged any more”, Lord Rayleigh (John U. Strutt) (in backward translation from russion)


#13

[QUOTE=Sonic2171;2622724]This is true for computer drives, but most dedicated audio transports should not have a problem.
My AMQR/GigaRec discs play in every audio player I have tried them with. :iagree:[/QUOTE]

Right!

My Meridian500 and Goldmund transport-Player like amqr. :cool: