changing the audio world, one system at a time .... church sound, video and lights

First Baptist Church in Tacoma - System Rewire

sanctuary from balcony sound boothSoundcraft GB8-40 board in sound booth
Chris Pak from First Baptist church in Tacoma contacted me about their system a few weeks ago. They felt that the system was not operating properly and there were some wiring issues regarding hum in the system. I don’t know who designed the system but I did meet the installer. The amplifiers were placed in the sound booth under the mixer, feeding the monitors and the main speakers from the balcony. The system design consisted of a center cluster with additional speakers for side fills all located behind the suspended ceiling.
The cluster: 6 boxes of McCauley M120 speakers, and 2 subs cabinets (mounted one on each side of the array) not sure what the side fills are.
The processing for the system: DBX Driverack PA The driverack was set to a JBL 3 way speaker system with subs. (The McCauley system is a 2-way box)
The sound was very thin and I could tell that the mids where none existent.

We programed a custom setting in the driverack and the speakers came alive with all kinds of good sound.


Now the wiring
A mess don't you think?more mess
This is what we encountered under the board.
First off, there are some basic rules when it comes to wiring a sound system.
1. Keep audio and power as far apart as possible
2. If possible never run then parallel with each other
3. If you have to cross an audio wire over a power wire, cross at 90 degrees

When you wire racks of equipment try to follow these practices.
Try to run the wires down the rack as follows :

Here is an example of how to wire racks properly

This way will maximize hum rejection from your power system.

Here is a picture of the wiring now. We still have some more work to do to really make it look good but the hum is under control now and they are getting clean recordings now.

rewiring, almost complete. Hum and buzz gone.
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