stuartk:
Lots of ways to spend money and improve systems but first priority is to have everyone happy in the house. If you have not done so, I suggest upgrading the wall outlets and fuses to your music source and amplifier.
The Synergistic Research Black fuses and their wall outlets come with a 30 day trial. It is a fun audio experiment to do, and for many the price performance gain is very good.
David Pritchard