Scanning CDs with the Benq 1650: BEWARE!

vbimport

#1

The Benq 1650 is a popular CDR scanner… but beware!
We already know that it doesn’t report C2 according to the usual rules, but there’s something else…

After having used it @24X an @32X for quite some time, I discovered three weeks ago a very, very annoying quirk which makes that most of my CDR 1650 scans are actually useless. :doh:
The hidden quirk is: ~ the drive is sensitive to severe disc defects only at slower scanning speeds, @12X being the most sensitive and @16X being the limit to detect the defects ~

The following disc has a big scratch, and has reading issues in all of my drives, including the 1650.
According to the scans performed @24X and faster, the disc has no issue. :doh: :doh: :a

I could reproduce these results with other scratched discs AND in my other 1650 unit, so it’s definitly not an isolated case.
So much for high-speed CDR scanning with the 1650! :sad:

I’ll post advanced scans later.


#2

[QUOTE=Francksoy;2068042]I’ll post advanced scans later.[/QUOTE]Here they are (over 2 posts).






#3

Continued from previous post






#4

Good to know, thanks.

Luckily I always scan at 16x :iagree:


#5

Interesting comparison of scanning speeds.

I have done similar comparisons on a BenQ DW1655 with a self-made test disc (using a black marker pen), and the scans looked fairly similar at different scanning speeds.

Looking at your scans, and based on my own experience, I have come to a different conclusion:

Use a scanning method that shows C2 errors of both the E22 and E32 types, not a scanning method that just shows C2 errors of the E32 type.

That could be an Advanced Disc Quality scan using a BenQ (Nexperia) drive or a PlexTools/PxScan using a Plextor drive.

That way you’ll get a much more sensitive scan that shows potential problems (E22) and not just downright failures (E32).


#6

[QUOTE=DrageMester;2068286]I have done similar comparisons on a BenQ DW1655 with a self-made test disc (using a black marker pen), and the scans looked fairly similar at different scanning speeds.[/quote]I did the same two years ago, and just like you also got similar results, which is why I’m baffled to meet this quirk now.

Maybe, like me, you made a self-test disc with a ray-ish black area and straight scratches (like this), if so I think I understand what happens: the scratch on the disc scanned above, as on the other discs which would show the same quirk in my 1650 units, are long, concentric scratches… I gather you guess what I have in mind. :slight_smile:

Use a scanning method that shows C2 errors of both the E22 and E32 types, not a scanning method that just shows C2 errors of the E32 type.
Of course it’s much better. :iagree: I’ve sometimes been lazy and inconsiderate. :o Luckily, I don’t scan in the 1650 to check media condition, but rather to test for burning quality jitter-wise. Pfeeew… or?

Cause… have you noticed in the scans above that both standard and advanced scans show dramatically different jitter levels for different scanning speeds? Now THAT’s what really worries me now. :doh: I’m performing cross-checks but I’m not sure yet if this is limited to marginally burnt discs (this Ritek above, for example, was a poor burn to start with). I hope it is, or my small personal database of CDR media/burner/firmware/burning speed combinations will need a big tidy-up. :rolleyes:


#7

I didn’t notice the very different jitter levels until you pointed it out. :o

Have you tried performing Transfer Rate Tests at various speeds to see if the drive actually reads the disc better at higher speeds?


#8

After reading this post I thought I would try a few scans, as I bought the 1650 for the purpose of scanning CD’s

The following scans were done using a Sony test CD, with black and red test bands (0.3mm to 1.1mm) and simulated fingerprints,
over music and 400Hz tones.

I can only say that I am happy with the results, as I always scan at 32X.







#9

Very interesting observations. Thanks for sharing!


#10

[QUOTE=Sonic2171;2069505]I bought the 1650 for the purpose of scanning CD’s[/quote]You’re aware, I hope, that the Benq/Nexperia drives (thus including the 1650) don’t report C2 as other drives and are not suited to scan CDs on their own?
They report C2=E32, though C2 “standard” reporting should include E22 (is that right Drage?)… so some important condition defects leading to reading issues (not necessarily failures) can’t be seen in scans from these drives, unless you use the Advanced scan and check specifically E22 and E32, just like Dragemester explained in his post BTW. :slight_smile:

My use of the [1650+standard scan] is specific, to check for burning quality (jitter, C1) and, if in a hurry, I used to consider that with no C2 reported, even with the limitation explained above, the disc was probably fine. Why not use Advanced scans everytime? Well, because I find these more tricky to grasp visually, and habits, darn habits… LOL

@Dragemester: with the disc in my first post, all TRTs fail at all speeds (in the 1650, but pass in my other drives :p). With other discs showing a similar quirk, TRT results are very inconsistent and don’t seem to be correlated with reading speed.

Actually, after lots of cross-checks, I gather that the problem exposed with E32 reporting at different speeds, is limited to discs with problematic physical condition before the burn. I’m not 100% sure but I’m tired to focus on this thing, while it’s more important for me, right now, to re-check 57 discs in my NEC 3540A. :rolleyes:

For the jitter/speed reporting quirk, I’ll perform additional cross-checks, but it seems to happen only with my Ritek and MCC CDs, and not with CMC, TY, Sony, Maxell… :confused:


#11

[quote=Francksoy;2069615]You’re aware, I hope, that the Benq/Nexperia drives (thus including the 1650) don’t report C2 as other drives and are not suited to scan CDs [I]on their own[/I]?
They report C2=E32, though C2 “standard” reporting should include E22 (is that right [B]Drage[/B]?)… so some important condition defects leading to reading issues (not necessarily failures) can’t be seen in scans from these drives, unless you use the [I]Advanced scan[/I] and check specifically E22 and E32, just like [B]Dragemester[/B] explained in his post BTW. :)[/quote] I would say that most CD scaning drives report only E32 errors as C2 errors in quality scans, so the non-advanced BenQ scan is just as good/bad as most other scanning drives (except that it reports jitter, unlike most other drives).

My early posts on this subject a couple of years back may have indicated otherwise, since my initial scanning experience was based on Plextor drives which reported E22 and E32 separately, so this seemed to me to be the “normal” behaviour, but unfortunately it is not.

The only non-professional CD scanning drives I would recommend without reservations are scanning drives that can report E22, but unfortunately such drives are no longer in production (to my knowledge). I’m not aware of any non-professional drive still being produced, that reports anything more detailed than C1=BLER=E11+E21+E31 and C2=E32 (but some report less or don’t report anything).


#12

[QUOTE=Francksoy;2069615]You’re aware, I hope, that the Benq/Nexperia drives (thus including the 1650) don’t report C2 as other drives and are not suited to scan CDs on their own?[/QUOTE]

I also have Plextor and LiteOn CD-RW’s (see sig) which I use for assessing my burns, as DrageMester identified in his post, I bought the 1650 mainly for its jitter facility.

However, because of the superior reading ability of both the Plextor and LiteOn drives, they will recover information from damaged/poor CD’s my other readers won’t, I have found that the 1650 will reveal/report borderline errors the others scan as OK.


#13

[QUOTE=DrageMester;2069619]The only non-professional CD scanning drives I would recommend without reservations are scanning drives that can report E22, but unfortunately such drives are no longer in production (to my knowledge).[/QUOTE]

What example of drive models would those have been?


#14

[quote=negritude;2135787]What example of drive models would those have been?[/quote] BenQ DW1655/1650/1640/1620 with Nero CD-DVD Speed or Nero DiscSpeed.

Plextor Premium2/Premium, PX-760/755/716/712 (perhaps 708?) with PlexTools or PxScan/PxView, (and also QPxTool I think).


#15

My Benq DW1655 seems to produce pretty consistent results when scanning CDs at different speeds (CD-DVD Speed ADQ). The jitter & BLER don’t change significantly from 48x down to 16x (although I have not used it much below 16x). It certainly seems to be sensitive enough to E22 errors at 32x (my standard scanning speed). I don’t recall ever seeing E22 or E32 errors that disappear completely when the scanning speed is changed.


#16

One other question, do you think this issue that Francksoy outlined is specific to the 1650/1655, or applies to the 1620/1625/1640 as well?

Also, I notice in the initial post that BCIC is being used. Considering how buggy that 1650 firmware past BCDC is, might it be prudent to test for the scanning anomaly with earlier firmwares?


#17

[QUOTE=negritude;2179084]Also, I notice in the initial post that BCIC is being used. Considering how buggy that 1650 firmware past BCDC is, might it be prudent to test for the scanning anomaly with earlier firmwares?[/QUOTE]Interesting idea. I’ll check that and report.


#18

Sorry but 've been clumsy when referencing my files and discs in this case, and I can’t find this particular disc anymore. :confused:
I’ll keep searching.


#19

I think your BenQ is in some kind not working well, cause I can not share your observations at all. My BenQs show very similar result with every scanspeed, C2 scanning ist totaly correct when you use Advanced scan. The resullts are so consistent and trustable that they are nearly everytime almost same results which produces my Plextor with the very same disks.

So two independent drives get same scan results with same media the best thing that can happen to trust the BenQ CD scans.


#20

[QUOTE=BurningFish;2194012]I think your BenQ is in some kind not working well, cause I can not share your observations at all.[/QUOTE]It’s very possible that you simply don’t have the relevant discs at hand! Remember that each media/burner/burning speed combination is unique :wink: and this was observed with scratched discs. I don’t know how many types of discs you use, and you don’t tell if you tried specifically with scratched discs…?

Besides, if you read my post well, you’ll meet this:

"I could reproduce these results with other scratched discs AND in my other 1650 unit, so it’s definitly not an isolated case. "

I’ve found a couple of relevant examples again, and will post them shortly. :slight_smile: