Ground loop isolators can be a godsend if you hear high pitch whine coming from your speakers/headphones.
Other Audio Equipment:
Dynaudio Mc15 Studio Monitors
My listening room is acoustically treated with a mixture of 8inch 60Kg rockwool Basstraps in the corners and 4inch rockwool panels at reflection points. Cheap and easy to make (following youtube guides) and worth it for the audio gains.
ipad 4, iphone 8, Nvidia shield tv, nintendo switch