Some major improvements:
- passive crossovers replaced with active, allowing for a multi-amp system
- dedicated AC lines with #8 wire and regenerated power
- equipment rack with hollow vertical tubes filled with lead
- added 160 lbs of lead to each speaker, added 100 lbs lead to each sub
Planning on adding Rockwool insulation to attic and interior walls to
help achieve my goal of 30 dB ambient noise level.