Desc: This is Carlon combination high and low voltage box. I used these in sub-woofer location where I needed power for the sub-woofer. There should not be a problem with contaminating the sound signal as the power goes up and through the ceiling and the RJ-6 quad goes down and through the floor space.
This also makes installing the sound stop board and drywall easer as there are less cutouts to make.
A big mastake was not using boxes with adjustable mounting brackets. Normal boxes are build for half inch thick drywall. This project calles for half inch sound stop board plus 5/8 inch drywall. Which makes the wall 1 1/8 inch thick. This still does not account for the one inch ridge fiberglass used for acoustic treatment.