Nice system... There's nothing like the 3D you-are-there of full range Apogee ribbons... I also have D. Sigs and after 30+ years of enjoying this hobby I have found them to be the most rewarding speaker I've ever owned. Let me ask you: How far are they from the front and side walls? How about from each other? Room size? Do you use a separate crossover to split the signal to your subs first in order to "lessen the work" of the ribbon woofers? Perhaps the X-30 at 50 or 80 hz? Just curious... I'm sure we could have lengthy conversations.
Once again... nice system.. Best regards PS: my virtual system hasn't been updated on this site with any new pics, it's still showing my previous Mini Grands, but I'll be correcting it soon.