How long is too long for interconnects?


I'm looking at upgrading the audio in my photo studio. I have some position limitations due to the lighting gear etc. 

Would it be a bad thing if I put my source and pre-amp up on a shelf and ran interconnects to monoblock amps located at the speakers? The lengths would be about 8 feet to the closest speaker and 12 feet to the furthest; I guess it'd be best to then purchase 2 x 12 foot interconnects, right? 

Any/all thoughts/advice greatly appreciated!
benchwarmer
If you have balanced (XLR) interconnects then no problem at all. If you have coax (RCA) connectors then it depends how much noise they pick up from the environment (hum etc), and the ability of the pre to drive a capacitive load. Best advice is probably to give it a go and see. There's no need to match the interconnect lengths, in fact I'd keep each one as short as possible.
Good advice so far.
XLR's for equipment supporting the AES Balanced standard is the way to go.-Cable coloration is minimized as a result.
12' for speaker cables will introduce more cable coloration than shorter lengths. So, you might want to demo a few different brands, if you are serious about sound.
B
Balanced/XLR is better than otherwise, certainly best chance of noise rejection.

Of course, your simplest choice is to run speaker cables that long.