what a neat setup you have! I love your LP racks, and the equipment tucked into the rack makes for a really unique look.
Regarding your subs... did you experience tighter bass when you added the 2nd sub? I have older 600 series speakers myself, and have been considering adding a sub, but I'm afraid that a sub will muddy things up a bit.
would you be able to comment a bit more on the changes when adding the subs?