Ok, here are the photos of a very inexpensive system in a 1 bedroom apartment. I have a wife that is NOT approving of my sound system. She would be very happy with just the sound bar. But, she is letting me be me. The first pic shows the crown amp at the bottom underneath the Yamaha receiver. You can see the ESL speakers that play louder than I can listen to without hearing damage or being evicted! You will also see the ML 700X sub that I got for free. I have it EQ'ed to hit 25hz which is all it can do. You can also see my less than $100 chinese special center channel below the tv. I tested (as I always do) the center channel by itself and it fills the apartment easily with fairly loud sound. My rear surrounds are $30 or $40 4 inch (50hz to 16khz) Pyle surrounds. They will also fill the apartment loudly all by themselves. So, I am not volume limited in any way. I do music listening with 2.1 channel only on "Pure Direct" through the Yamaha.
The next photo shows my custom room treatments which do double duty as bins holding the wife's holiday decorations etc for all holidays. The last photo shows the other wall and its custom treatment of the cat bed (which he appropriated!) chairs and the half wall to the kitchen. Also it is 100% carpeted with cloth furniture for the listening positions and more back wall treatments. I believe the free custom room treatments really are what make my system sound so good.
That's my system. Oh and you will notice the unconventional toe in of the ESL's. It makes the sweet spot center image at the TV. I have a great left/right and center soundstage but almost zero depth. The sacrifice for apartment living. No musicians seem to be behind the tv or the wall. I should add up what I have in the system as it is not a lot of money compared to most people who are into audio. I feel I have tweaked this till it sounds very good for a small apartment setup. Oh, and I'm adding a 31 band stereo EQ tomorrow too. That will finish it.