I just want to share my experience ravamping my HT. It has come alive in ways it never had before, even keeping part of the original equipment. My HT measures 16.5' front to back and 14.5 wide. I had an Onkyo TX-NR1000 AVR setup in a 5.1 config with Polk LSi 9 mains, LSiC center and LSiFX surrounds. I also had a Polk PSW1000 subwoofer. Everything was wired with 14awg wire. Sources included AppleTV 4k, Dish Hopper, Oppo BDP-105D HD BluRay player, and a Technics SL-1210M5G turntable. I have a 75" Samsung LED display.
I was never fully satisfied with the sound because I had to place the LSi9 speakers inside the curio cabinet of the wooden built in used for the AV gear and everything rattled when I had strong HT scenes. The surrounds were too high on the side walls and eventually the subwoofer's amp blew out.
So, I decided to redesign the HT to bring it up to date. First, I got a new AVR: I decided on a Yamaha RX-A8A. Amazing receiver! I complemented it with an AC Infinity Aircom T10 blower fan.
I changed the surround configuration to 5.1.4. I chose to lower the LSiFX to ear level and set them up in bipole mode. To add front and rear presence/height speakers, I repurposed 4 Polk RTi4s that I had in other zones. I placed them on wall brackets 8' above, on a 20 degree angle towards the primary listening position. I rewired all the speakers with Monoprice 4 conductor OFC 12 awg wire in biwire config with locking banana plugs. I replaced the subwoofer with an amazing SVS PB3000 and used a Mediabridge cable with dual RCA connectors on the subwoofer side.
I finally managed to fix the vibration and shaking of the built-in cabinet placing each LSi9 on top of 3 IsoAcoustics IsoPucks, which in addition allowed me to bring the drivers front side a few inches outside the cabinet. I also placed soft silicone bumpers on the pins holding the glass shelves in the curio and placed felt bumpers under each of the items on the shelves.
I kept all the original source equipment, now connected with Monoprice 8k Certified HDMI 2.1 cables. I used Yamaha's YPAO RSC 3D to calibrate all the speakers.
Altogether, this setup sounds like a whole new system! I am really pleased with the result. The addition of the four height speakers and the new amazing subwoofer really fill the room. Bringing the surrounds to ear level allows me to take advantage of the Yamaha Aventage AVR decoding Atmos and Auro3D capabilities. The Polk LSis sound amazing for 20 yr old speakers. Given that all of them use the same drivers, they are perfect for Atmos sound objects. The RTi4s blend in very well as height speakers.
There is still room for improvement. Eventually, I'll get an LG G2 OLED display and a 4k BluRay player. Later on I may eventually replace the Polk LSi speakers.
My message to you is that you can create a whole new experience in your HT with incremental changes in the setup and gear. It's not necessary to get a second mortgage to replace all pieces of equipment at once and you don't need to throw your money away on sneak oil cables. Furthermore, you can repurpose other components to improve on your HT design. I hope you find some value in my sharing this experience!
