I'd be interested to know as well why you'd like to burn below 16x. With modern drives and half-decent media 16x should be quite adequate - unless your drive is a modern one, but one that just isn't a good CD burner (yes, there are some around even now).
16x is the lowest I'll go, and that's usually only for audio CD burning.
So on that note, what media are you using and what drive do you have?
BTW, welcome to the forum.