Hi
Measure, it will tell you somehow what you could be missing ... I don't think (WAG wild-assed-guess
) you are missing too much. TO make it better IMHO:
Things you can do at, or near, zero disbursement:
Measure. Carefully and don't get too worked by the measurements. You need to interpret these accurately. People will help. If you don't have it already , it will cost you the price of the go-to measurement microphone , the miniDSP Umik-1, about $100.oo on Amazon or other...
Download the Audyssey App for smartphone. And... that is where it gets a bit dicey: You need to bump up a bit the subwoofer output ... create if you will a house curve.. As it is Audyssey on the AVR or with the App, EQ the subwoofer to a bass-shy (for many people, including I), profile.. A gentle slope from 20 to 80Hz say up to 5 dB at 20 Hz to 0 dB at 80 Hz is what you should target... It is not easy, with the app, since you have to use your fingers and even if you were to use a bluetooth mouse, it would be not that perfect but it can be good enough to satisfy most... A bit of practice will take you there. The app is $20.oo on the usual IOS or Android app markets. Audyssey has now a PC app that will perform a lot more and more precisely.. I amthinking about it but $200 for a license that can't be transferred to another receiver is so far to me a non-starter... I may bite the bulet.. While you are int he APp, remove the midrange compensation, the LFC but and there I insist, please bring DEQ on... TO me a revelation.
Things that will cost you more but better results:
Of course everything in the first part (near -zero) Plus:
An additional sub. I am no fan of REL, which I find expensive for not great results, Keep it but
add another subwoofer, something else, in that small room an SVS SB-1000 Pro could be all you need to get in the low teens ( under 15 Hz ...
)...
You may need to download MSO (Multiple Subwoofer Optimizer)
You absolutely need, IMHO, a miniDSP2x4 HD, for about $250.oo..
The Audyssey PC App, mentioned above at $200.oo.. I don't know it enough, but some people say it can work with two subwoofers .. IDK and since I already have the miniDSP 2x4, I wouldn't bother.. but it is powerful and make Audyssey even more flexible and more fine-grained...
As for room treatments.. my experience is to make sure your attenuate the first reflections , the floor and the ceiling .... and leave the room alone if it doesn't present too many reflective surface... Other will chime in but in my case that is what I did and am pleased.. very pleased.
In both cases you will have to research a lot, study a lot and work too, .... a lot.. At the end you will end up with a close-to-end-game system for all your needs 2-ch, MCH, HT or gaming ...
Peace