EAC write offset for a Benq DW1640

Could anybody tell me, what is EAC write offset for a Benq DW1640? (According to http://www.accuraterip.com/driveoffsets.htm read offset is +618), all help appreciated, thanks.

Probably the same value as the other Benq 16xx drives -> +66

Thanks for reply, i have just thought same, as all 16xx have same read offset, just need confirmation. Btw thanks for your work on MediaCodeSpeedEdit:)

Well my drive is +618. Tested it myself with 3 different cds.

thanks for reply, but you refering to read offset, question was about write offset.

Ah yes, sorry didn’t notice. Well according to my profile write offset is +138. But it’s been a while since I used the BenQ with EAC…

Thanks again for reply, tho it gives 2 different value of write offset, all previous Benq drivers has read offset +618 and write offset +66, DW1640 has same read offset +618, logically it should have same write offset aswell as previous one +66. If anyone more could confirm this new write offset +138 it would be great.

Why don’t you confirm it yourself?

Set your suspected write offset value in EAC, Create an Offset Test CD, and then use that CD to determine the Read Offset again. If you get the same Read Offset value as before, then you have the right write offset - if not, you can calculate the real value from the Read Offset you did get.

thanks for answer, i know procedure, simply drive is not mine, i was asked by person who has basic knowledge about burning, i mostly configure his EAC by phone based on my knowledge, but conc write offset i have just hope that i get one value here.

I’ll see if I can double check it tonight. No promises though…

Q.

(Hmm… wish my first name was Ben).

thanks, appreciate.

When I do tests with my 1640 I get two different answers for write offset which I know doesn’t sound correct but I know what I am talking about. The two different write offsets I get happen to be +66 or +138 which just happens to be the two numbers in question in the previous posts.
The read offset of +618 I know is correct. What I did now was enter that value of +618 into the read offset section in EAC and left the write offset at 0 to start. I ripped a couple of songs from a CD and then created an audio CD using the EAC built-in writer function and again, right now, the write offset was set to 0. I then ripped the songs off of the newly burned CD and used the compare wavs function in EAC and the calculations come up with a write offset of +138.
I also tried the method suggested by DrageMester and inputted +138 into the write offset section in EAC and created an offset test cd using the built-in EAC function. Then I used the EAC “detect read sample offset correction” function and it comes up with a read offset of +618 which is exactly was expected. Therefore, one would assume the write offset of +138 is the correct answer.
But some further testing brought up some confusion. If the read and write offsets as determined are correct, that means the combined read/write sample offset correction should be +618+(+138)=+756. I input this +756 number into the EAC combined read/write offset box and made sure this value was enabled in EAC (the use read/write sample offset correction is enabled). I then ripped a couple of songs from a CD using this combined read/write offset of +756 chosen. So what really happens is that the songs have been ripped with a read offset of +756. I then used Nero to create an audio CD. Then ripped the songs with EAC from the original CD and the newly burned CD and did a wav compare with EAC and the result are not equal as they should be. Doing the calculations with this new result determines a write offset of +66 now instead of the previously calculated +138. If I repeat this test again but use a the combined read/write offset of +618+(+66)=+684 and do the same thing with burning the audio CD using Nero, then the wav compare comes out equal.
So I have determined that when using EAC to both read and write a CD then the values of +618 for the read offset and +138 for the write offset should be used. But if I only use EAC to read a CD and then use another program such as Nero to do the writing, then I have to input a combined read/write offset of +684 which actually implies a write offset of +66 in order for things to work out properly.
I assume anyone could repeat my findings.

thanks for sharing your tests, anyone more?

Looks like Dent is right. :slight_smile:

EAC to both read and write the CD:
Read offset=+618
Write offset=+138

EAC to read and another prog (Nero, Padus, whatever) to write:
Combined read/write offset=+684

While I didn’t test this now, I got the above values in my 1640 profile too.

Q.

thanks for your nfo Qyngali.

Hi folks,

determing the correct write-offset for the DW1640 is actually a bit confusing.
But I found out that the write-offset depends on the write-speed you’re using.

When writing a disc at full speed (48x) a write speed of +66 is the correct one
(I created a test-CD using write-offset = 0 being done @max speed)
-> I used this disc to determine the combined read/write-offset which was
+684 (read-offset: +618 and write-offset: +66)

After that I used +618 as read-offset and +66 as write-offset and copied a disc to see whether everything works correctly
(for testing I set the recording speed to MAX (=48x)

After that I comapred the originally extracted wav with the reextracted from the copy… they were identical!!

However for high quality backups I always use a write speed <= 16x and when comparing wavs, I noticed that there were 72 repeated samples :confused:

==> the write-speed has changed. It was +138!!

Maybe some of you have experienced the same!?!

@DENT: You’re right! When using any other burning proggie, such as nero the write-offset is always +66, no matter what write-speed being used!

So EAC must handle things a bit different:

write-offset = +66 for max-speed in EAC
write-offset = +138 for any other speed in EAC

nice that post alive, i have just wondering may it be EAC bug internal?

@superzap2,

When I did my tests with EAC and Nero I was only using a rewritable CD which has a max write speed of 10X. Good to know that if use a normal CD-R and max speed in EAC then the write offset becomes +66 but if I use a write speed of <=16X then the write offset becomes +138 (which is what I found in my tests because of my max write speed of 10X). Your tests using Nero with different write speeds is also good to know as I wouldn’t have known that with my own tests either.

When copying a CD I usually always use a max write speed (48X or maybe drop down one level to 40X) so I can just set EAC to use the +66 write offset and be done with it. I actually haven’t repeated your tests because I didn’t want to waste a CD-R and I haven’t copied a music CD in quite a while now but when I do, I’ll be sure test out your assertions.

I always burn audio CD using the EAC built-in writer function and I did some tests using the latest EAC version 0.99 pb4. (and wasted 2 CD-R)

My results are:

  • Write-offset = +138 (for write speed of 4x in EAC with a Philips CD-RW)
  • Write-offset = +138 (for write speed of 10x in EAC with a Philips CD-RW)
  • Write-offset = +138 (for write speed of 16x in EAC with a Sony CD-R)
  • Write-offset = +66 (for write speed of 24x in EAC with a Sony CD-R)