Totally different scans: same disc

[Pain_Man]

Decided to see what differences there would be between running scans in the BenQ DW1655 and the Pioneer 110D 1.39. Since DIP doesn't scan CDs (yet, it assures us), I used Nero CD/DVD 2000 (latest v. 4.51.1; which comes with v. 7.2.0.3 or you can download it separately at www.cdspeed2000.com

 

I used a CDDA copy of Bach on Lute, Disc 1, Nigel North, lute (6 course, for those interested; it's an excellent 4 disc set of music Bach wrote for the lute, and for a rare machine called, in German, a lautenwerk, basically a keyboard strung with lute-string as well as some transcriptions). The disc I used is a Sony CD (not a rebrand).

 

For those wondering why the scans weren't done at the same speed, the Pioneer will scan only at its tops speed (40x). Oddly, the Pioneer's avg speed is half the BenQ's. The way I understand it is that scanning at slower speeds should produce more accurate results (by all means, correct me if I am wrong).

 

First scan from the DW1655:

 

 

Not bad.

 

Then I scanned it in the Pioneer 110D:

 

 

What the hell??? 5666 C2 errors? This disc should be a coaster. According to this second scan this CDR (which I burned only a couple of months ago) shouldn't be playable!. Notice that scan 2, from the Pioneer doesn't even have a jitter measurement. I don't know if there's some compatibility issues with the software and the drive; I'm going to run some further comparative tests, even with some pressed discs, to see if this wild-assed discrepancy is a fluke or something stranger (you know, maybe it's Them!!!!)

 

I've noticed some differences in DVD scans using this tool and the two different drives but never something this wild.

 

Any ideas what could cause such a wild discrepancy?

[LIGHTNING UK!]

You shouldn't ever compare scans between different drives. It just never works - as you've now seen!

 

I believe the BenQ drives (philips chipset) are the only ones that support jitter measurements.

[chewy]

also at maximum read speed in a scan are you graphing burn errors or read errors?

[Pain_Man]

You shouldn't ever compare scans between different drives. It just never works - as you've now seen!

 

I believe the BenQ drives (philips chipset) are the only ones that support jitter measurements.

 

 

Thanks, Lightning. That would explain why I couldn't get jitter measurements out of the Pioneer.

 

 

I assumed there'd be one standard for testing (like there is for, say, gas mileage for cars, the infamous CAFE standards in the US).

 

Obviously...NOT!

[Pain_Man]

also at maximum read speed in a scan are you graphing burn errors or read errors?

 

 

To be perfectly honest, I don't know.

 

I thought the C1/C2--PI/PO were scanning for read errors. Is this wrong? (If it's not a burn error, then is the inference that the problem lies in the content?

 

Also, I didn't see a choice. The Nero Tool calls it a Quality Check. DIP just calls it "PI/PO Jitter test."

 

Can one use these tools to test for both read and burn errors?

[chewy]

you are graphing both read errors and burn errors, the goal is to set a slow enough scan speed to minimize the read errors, not an exact science at all, just an attempt at it

 

repeat the pioneer scan at a much slower speed and see if you obtain different results

Edited May 14, 2006 by chewy