Placement within your reason/available space, balance all channels to same db level, and if using a sub...use a good one (svs, hsu, velo, ED, JL). Some damping in room (sofa, drapes, pillows) as well as some reflection from walls/ceiling. I do believe you can replace pwr cable (signal here at the gon). If recv'r is calibrated to reference your vol indicator lets you see at a glance approx level compared to reference level of about 105db. This is based on Dolby/DTS reference level for movies. Remember, it takes a doubling of output pwr to increase 3db...thus at a -24 level you are wwaaaaayyyyyyy far from amps capability when it is going to take twice the given pwr to go from -24 to -21...got it? Your 2805 tops out about +16 or so...perhaps +18/+20. Friend has a **02 series and my son has a 1602 in his ht rig I put together for him. Theirs go to +18. Anything past 00 would hurt you or small creatures in the vicinity if setup properly. Use the auto setup feature for spkr distance and level calibration if you have the mic that come with it. Otherwise as advised, use test tone and adjust ch trim so that all are same on spl meter reading 75 db with master gain set at -10 or 85db with master gain set at 00 which most people find much to loud/annoying. I advise -10 on master volume knob and adjust until the test tone reads at 75db on spl meter so you don't damage your spkr drivers.
