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At North Ridge Community Church I was moved into the lead sound tech position a few months back. It was my job to document the system and make an inventory of all the equipment, along with that make sure all of it was in correct functioning order. Over these last months I have found more than I could have imagined wrong with the system. I have a laundry list of items setup wrong, not connected correctly, NOT CONNECTED down to things being broken.
Tim Corder, http://www.cordernotes.com, has a great audio blog online and if you get a chance you should really read it, he has some great information on there. One thing that he stresses and I completely agree with is trust nothing that was previously installed before you. Basically, this is saying that if one is the lead sound tech, it is his/her responsibility to make sure all of the system is in working condition and correctly setup, so take nothing for granted.
I will start out with a few of the major things I have found wrong with NRCC’s audio system:
- 3 of our 9 amplifiers in the amp room do not produce sound out of any speakers.
- Speakers in the main array have wires coming out the back of the speakers which are not connected to anything.
- I have found splices in the wires made with wing nut electrical connectors up at the main array. (this is probably the reason behind the 3 amplifiers not hooked up to any speakers)
- System Equalizer setup improperly causing “Phase distortion” which makes the sound system less defined and lacks clarity.
- Speakers are under powered, giving the speakers 1/3 of the power the speakers need. This is causing the amplifiers to distort much before our speakers will. By under powering speakers, the speakers are not able to reproduce the sound as well as a correctly powered speaker.
- Necessary delay times for the speakers are not present in our system. The 6 flown speakers are at different distances from the congregation which would require separate amplifier channels and delay times. However, all of those 6 speakers are powered off of one amplifier. Our front fills (the four speakers on the stage) have this same dilemma being powered from one amplifier.
- CD recorder was fed with incorrect polarity signals which caused cancellations of frequencies. This made it so anyone listening to those CD’s would have to turn up their stereos to full to be able to hear it even though it was recorded with full levels on our CD recorder.
- Our current system processor that handles the distribution of audio from the sound board to the separate amplifiers requires a PC with Windows 95, 98, ME or 2000 installed on it to even log into the processor to change settings.
- Audio Grounds not isolated at system processor and monitor amplifiers causing ground loop issues (hum).
- The negative wire of a balanced signal output from the board for the main array send was pulled out at the system processor leaving only the positive and shield connected causing lots of hum and noise injection.\
- Unity gain being sent only for the main array. Monitors and subwoofers (sent via Post Aux send) were not receiving unity gain because of improper gain structure via the amplifiers and system processor.
So this is a good portion of what I have found so far in the system at NRCC which is wrong. The awesome part of my job is fixing these piece by piece and discovering how much of an impact each little thing makes.
Onto my next subject, our speaker system.
In the main cluster in the center is: two EAW KF650e (top) and two EAW KF300e (bottom) for the down fills. The side fills are one EAW KF650e on each side. Front fills are using the EAW JF50s which there are four of them. Lastly we have our EAW SB625zP dual 15″ subwoofers, one on each side of the stage. These are powered using Crest Audio and TOA amplifiers. System processor is two TOA DP-0206.
I have an EAW representative coming out to inspect the speakers to check functionality of the components in the boxes and verify that they are hung in the correct alignment. As far as I can tell, they look to be correct. The KF650e’s, which are the main array and side fills, have a vertical throw of 45° and horizontal of 60°. The KF300e’s, which are our down fills, have a vertical throw of 45° and horizontal of 90°.
Finally, a great shot of the depth of the room with the mix position on the 2nd floor balcony.
Next post is going to show some of the wiring nightmare at the main arrays. Like always, if you have any questions feel free to ask. Thanks for reading.