So I have a Yamaha mg 32fx board an am interested in auxiliary feeding my subs, anyone have experience doing this? what will I need to do to try this? Will I need a Driverack or anything like that? any help would be appreciated.
All you really need to do this easily is a patch bay. This makes it possible to re-route your auxes / subs or whatever without having to go behind your board. I have the same board except it's MG24/FX rather than the MG32 so all the routing is the same. All you need to do is press the aux button for the channel(s) you want sent to the subs and patch the aux return to one of your group outs. Then patch the group out to whatever sub source you want. Hope this helps.
Why do you need a patch bay for anything? Just plug it into the mixer. It's one cable, and it's not like you're going to be switching it in and out during the show.
If you're feeding an amplifier and regular passive (unpowered) subs, yes, you need a crossover or some kind of 2nd or higher order low-pass filter in between the console aux out and the amplifier. A simple analog 2-way crossover from which you're taking the low frequency/subwoofer output is perfect for this. Set the crossover point at 80-95 Hz, depending on your particular subwoofers and personal taste.
If you have self-powered (active) subs with built-in amplification, virtually all of those have built-in filters, so you can just connect the console aux out directly to the sub input.