This blog entry comes with a MAJOR Nerd Alert! If you're not fascinated by the subject of burning audio CD masters, READ NO FURTHER!
I was responding to a forum question about optimal CD-R burn speed for an audio master, and found I was practically writing a novel on the subject. So I copied it over to Blogspot, and here's my two cents about audio CD burns:
The optimal writing speed is dependent on the burner and the media. For a long time with the old Sony CDR 100 mechanisms 2X was considered optimal - better than 1X. This had to do with the rate at which the plastic heated and cooled as data was being written. Slower speeds are traditionally better, but the newer high speed burner mechanisms are unstable at very slow speeds.
On my current NEC (via LaCie) burner I have standardized around 8x after some trial and error. This seems to be the slowest stable speed for this burner. Higher speeds were producing disks that some machines could not read.
One aside is that very old CD players can have difficulty reading newer 80 minute CD-Rs. This is a function of the machine not being designed to read the more densely packed 80 minute discs, and not necessarily a flaw in the CD-R itself.
Using good media is important, and the quality control of a given brand can change over time, so always be suspicious if a brand switches manufacturers. I currently use Taiyo-Yuden media and sometimes a premium disk called "Green Tunes" which is specifically for mastering.
It can give you some peace of mind to use burning software such as BIAS Peak, which will do a verify pass on the finished audio disk- i.e. it reads back the data from the CD and compares it to the files it just used as a source for the burn. Always go for the verify pass if your burner supports it.
Another increasingly common option is to forgo the CD-R and deliver your master as a DDP file set. This can be burned onto a CD-ROM or zipped and sent to the duplicator via internet. A DDP file set is considered a more robust format because it does not depend on the vagaries of the Red-Book Standard audio CD format. Not all burning software has this ability, so make sure it does. In Peak it is an add-on module.
Re. Red Book audio CDs: In order to get as many minutes of music possible onto an audio CD, the actual formatting of the disk crams more data onto the disk than the same disk formatted as a CD-ROM. This makes for a more error-prone disk. That is why audio CD-R may not be the best format to deliver a master.
For my money, in addition to using premium media, an optimal burn speed and a computer verify pass, I would also proof the master over headphones before letting it go out. You'd be surprised what sometimes gets by the mastering process. Hopefully your client will see the wisdom of paying for that extra step.
So that is my accumulated wisdom on the subject. Good Luck!