Have a project in a new hirise condo that has me stumped, and the client upset. He wanted FM Radio over the air. We actually were able to get a signal for the stations he wanted. We had installed a Triad DS4/9 in ceiling sub that was powered by a Triad Rackamp 300. The rack is in a utility closet. The rack has a Marantz PM8006 integrated amp, The Triad Rackamp, a Denon DN-300DH Tuner, a Crestron MC4 Processor, a Trendnet 8 port POE switch, Verizon Modem/Router, and a Terk AM-FM antenna.
Whenever we turn on the Triad Rackamp on, reception is killed for the FM stations. We are limited on where we can place the antenna in the closet, and don't have any easy way of relocating the tuner anywhere else.
The client finds this unacceptable. Anyone have a clue what to do?

Having done a handful of Triad rack amps I have not had this problem.
Why not stream. The switch is right there, you can control it from whatever control system you're using, or a phone or tablet;
                                             OR
1-Try another sub amplifier
2-I would run an rg6 or rg59 to a location outside the closet for testing purposes and see if this helps.
3-Try a non-directional interconnect for the sub-amp cable and the tuner cable that has  the ground connected at both ends. The directional cables as you probably know have the shields connected at one end only.
4-Try an antenna other than Terk. I have found their products to be questionable and usually outperformed by bare wire.

Then of course you will have to check all your AC cords and grounds