I’m about to push the button to get 2 SVS 3000 micros to add to ATC SCM40s.

Subs do take time to break in, you may need to use bass traps to get the bass just the way you want:

Agree the subs likely need some time to loosen up and settle in.  

Try them in different positions around the room.

Thanks for reminding me about the break-in period. In my excitement over new gear, i forget several important things, such as this and turning off my Loki.

Unfortunately, there is absolutely nowhere for the subs to be besides where they are--peeking out from behind the mains. If I were single... maybe, maybe not. It's a weird, open space.

@m669326 I usually adjust one sub at a time. And yes, be patient with break in  

How big is your room?

I would say that if you also want optimal performance, good quality power cables and subwoofer interconnects can make a profound difference in the speed and definition of the bass.