Anything goes in a dedicated audio man cave but you can bring the gear into a family friendly environment if it’s done with some aesthetic judgement. The elements of good design are: symmetry, unity and variety. Variety is over used and unity is underused.
The big black OLED can be balanced by making a block to raise it to the height of the 3.6 Magnepan speakers. This creates a unified black shape around the home built white cabinets.The same satin white finish is used on the GR Research W/Frame Open Baffle subs.
Four inch Owens Corning 703 board in a wood frame and covered with Magnepan fabric is behind the speakers. This prevents comb filtering.
I built the GR Research Open Baffle W/Frame subs using Rythmik A370PEQ amps. The subs fill in the bottom frequency’s for the 3.6 speakers, which are cut off at 50hz. LFE from the surround system does not go to these subs.
Bottom are switch boxes so the front speakers and subs can be used for either stereo or surround. Top is one M700 amp with Anticable speaker wire and a side view of 4" sound panel. CAT 6a ethernet routing box on wall.
Three thermostat controlled cool fans in rear panel. Front doors are slightly held open by a rubber eraser sitting sideways for ventilation.
Interior shelves were cut to enhance ventilation.
One of the M700 amps is in the center speaker compartment with a Mackie HR 824 near field monitor. My usual center Magnepan CC3 became delaminated. Re-laminating planned when I get a “round toit”. The Stratos amp was custom built by Klaus of Odyssey and now does duty for the Magnepan 1.7 side speakers. The rear MC1 Magnepan wall mounted speakers are powered by the NAD amp. At the top right is a powered remote controlled door opener that does not work yet. This will enable remote control of the DirectStream DAC and the Oppo BDP-205.
Light colored Magnepan speaker cloth blends into our wall color. Speaker wires were routed over the ceiling and down the walls. The same speaker cloth was used on the 703 sound panels to add unity - a major element of good design. More sound panels will be added to the room for better room treatment. Nyal Mellor will help me with room treatment: http://realtraps.com/art_measuring.htm
1.7 feet were offset to tuck back closer to the wall. It was nasty work getting these speaker wires in place. 
The wall mounted MC1 speakers can be folded back against the wall when not in use. 