Is it possible to run two subs on the 4306? If so what would I need to do that? Will they continue to run the same or will the information sent to each be half?
The best way to do this is using a sub with low level inputs and outputs. Take the sub-out (or pre-out with stereo) into the first sub. Run the second sub off the output of the first sub. My B&W sub allows for this type of connection. Alternatively use a splitter cable out of the back of the amp, this will also work well.
Nope. Both subs "see" the same signal. I've run dual subs like this before without any problems at all.
You shouldn't have! The auto setup should iron out the lumps, the gain of the subs will need to be a little higher as the signal is split but that will be compensated for by virtue of the fact there are 2 of them.
Ideally they'd be the same distance, if not, then give the auto setup a whirl and see what it comes back with.
I would have thought Audessy was clever enough to sort multiple subs out and provide a smooth response.
It is, but the only Denon with Audyssey that can properly EQ multiple subs is the A1XV(A). It will do up to three.
Russell the easiest way is with a phono splitter. My Denon at least will send a full range signal to a split phono connection (I use a Chord male to two female phono cable). As regards, Audyssey I found that it was better to just eq the one sub and then send that signal to the second and make manual adjustments if necessary. It is a shame that Denon didn't include the multiple sub aspect of the A1 lower down as many of us have two subwoofers.
I had it specially made Russell, but have a look here http://www.nexxia.co.uk/Hi-Fi&TVaccessories/phono_adaptors.htm Look at the "Two Socket to plug Phono Adaptor gold Pair" [/I]as I think that they would do exactly the same job.