If you wanna know what you are missing... go to the next big audio show and see what is out there.
I'm not interested in speakers $60K.
(OK... there is this
one pair at 50... but... no.)
(And then there is
this $10K pair... more realistic... but is it worth the upgrade? ('K, I'd like to think yes, but... no.))
On the other hand, there are many great speakers at even less than a 20th of that last one.
But Subs do not come that cheap. Hsu is your best Value at cost-to-performance.
Unless you go the DIY route. And the same can be said for speakers. There are kits for all, that you can build, with Flat-Pack Cabinets that will outstrip anything retail by far... You just need a little know-how and craftsmanship.
And the only reason I brought up the AVR is to get you better features for Room Correction and the ability to control what is going on. Not a priority... just a possible path forward when you get a better grasp on the other variables.
Address your room and placement options (free, or inexpensive if approached smartly).
Subwoofer.
Speakers.
Electronics.