Okay, so I have a pair of Martin Logan motion 10's from 2009-ish. A REL T7 sub from 2013. A Yamaha RX-V473 and I'm playing music from a laptop via the HDMI cable to the receiver. My speaker cables are pretty decent, think I paid like $80 for the pair. What should be my next move for an upgrade? I have about $1500 to spend.