dual subs from 1 output

[buckshot]

i'm currently upgrading my surround system piece by piece. i bought new floor standing speakers, got all new wiring and cables (monoprice.com), and am going to upgrade my receiver to an onkyo tx-sr674. i also want to get a velodyne 12" sub. what i want to know is; can i use both my old sub and the new one but with only 1 sub output from the receiver? would it significantly imapct the performance of both subs? it would be nice to have subs at both sides of my room, but not at the cost of quality.

i know little of surround sound systems if its not easy to tell.