I've made a lot of DVD-9 DL discs and once over the initial experimental phase, haven't had an reports of player incompatibility.

The book type is the main issue. Most older - and in fact some newer - players don't recognise the book type of DL and that's usually what stops the disc playing. The trick is to buy DVD+R discs and change the book type to DVD-ROM, then everything will play them. Although you'd think DVD-R would be more compatible, it's not, and you can't change the book type.

Then just stick to the general rules of disc burning - don't go overboard on the data rate and if you're feeling really conservative, don't use all the disc surface.

Thanks,
we're only duplicating these disks in towers. Only reason for going to DL is these concerts run over two hours and with so much fog, smoke, flashing lights and general mayhem I need a decent bitrate or things get ugly. Already thanks to previous advice from here using DVD+R.
So here's a question. How do I do a DL DVD and set the book type?

For single layer I usually prepare in DVDA and burn with Nero. I use Nero to burn because it gives me a verification pass. However I don't see how I can use the same process with DL, how does Nero know where to put the layer break like DVDA does. As far as I can see DVDA doesn't let me change the book type or have I missed something.

Bob.

I have Plextor drives and they can be set to automatically change the book type via Plextools. Ergo, I don't have to worry about doing it in software.

I do recall that changing the book type was not possible with all drives; there was a Lite-On utility for their drives (and the Sony OEM drives they make), perhaps yours too?

Nero 8.1 is pretty much automatic when making DL DVD's. You can manually set the book type if you want. I ran one through and didn't have to do anything, Nero set the break itself and the default book tupe is dvd-rom.
JJK

>So here's a question. How do I do a DL DVD and set the book type?

Yes as mentioned above, whether a DVD +RW/R writer supports user controlled Book Type is a function of the drive's firmware. Some writers do and some writers do not. I have found setting the BookType to "DVD-ROM" a critical factor in increasing DVD +R/+R DL compatibility and therefore only purchase DVD +RW/R/DL burners with the ability to "change the compatibility bitsettings" (i.e., Book Type).

My BenQ writer has a software utility that allows you to change the default Book Type for each of the media types it supports. Other writers allow 3rd party programs like Nero to set the Book Type on a burn-by-burn basis.

To determine if your DVD writer has Book Type setting control you can try visting:
http://www.cdrinfo.com/Sections/DriveComparisons/Home.aspx (select your model and then select the "DVD Recording Tests" or visit http://www.dvdplusrw.org/Overview.PC.asp?mid=14&sid=15

Thanks to everyone for all the advice.
I've now tried this D/L disk in another player. No compatibility problem however this somewhat older and cheaper player does have problems playing the first half of the disk which I assume is the bottom layer. That makes sense, the bottom layer of the disk has to be more difficult to read than the upper one and a weak / cheaper laser is more likely to have issues with a D/L disk than a pressed disk. Maybe the book type has something to do with this but I'm not certain. This same player still plays single layer DVDs to perfection.

So maybe in the end using a single DL disk instead of two single layer disks isn't worth the hassle and risks of getting more returns. It certainly is borderline cost wise. A DL disk is 3x the cost of a SL, you save a little on printing and the case are only a few cents different. We migh try one run of DLs just to see how many returns we get.

Bob.