A really daft question!
 

a avid 16 x 16 interface - will it record 16 tracks at once?
so for example a full band setup and recoding with 32 inputs recording together you would need 2 16x16 interfaces?

Re: A really daft question!
 

Exactly. Your numbers are correct, but it gets a little deeper because of the 3 variations of HD IO box. They are:
"standard", which has 8 analog IO and 8 digital IO(on TDIF, AES or lightpipe)
"Digital", which has only digital IO
"Analog", which has 16 analog IO

This matters because you need to get the correct version(s) to suit your other gear. Example; if you are using an analog console, you need the analog IO. But if you are using racks of external mic preamps, you might be able to use some digital connections(which might save you some cash).

Keep in mind that the HD IO boxes only work via a "Digilink" connection(so you can't buy a pair of them to use WITHOUT having an HDN or HDX card and Pro Tools HD or Ultimate software)

Re: A really daft question!
 

perfect
thanks dave!