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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Installed Sound/Contracting => Topic started by: Joseph D. Macry on July 22, 2021, 09:51:51 PM
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I am an A/V tech for a large school district in Texas.
This morning, I got a call from an Elementary school, they said one of their speakers had fallen from ceiling of gym, could I please replace it and BTW get HVAC guys to fix dripping water because it was going right through the speaker.
Arriving, I discovered:
- The speaker was El Cheepo, to be expected when they are procured from bake sales and donations. Not meant to be flown, but rather stuck on a pole.
- The leak was not from HVAC, but likely through the roof from thunderstorm. Must still follow up with that crew.
- It, and it's pair partner, were NOT meant to be rigged. Rigging was two chains around high strut, eyebolts through back of cabinet, backed by... a single nut.
- Water made particle board cabinet fall apart, eyebolts/nuts pulled out of cabinet. Luckily, gym was unoccupied for summer.
- Gym speakers are wired incorrectly into in-wall amp of adjoining Cafetorium to serve as overflow space when airwall is opened.
I can forgive a school getting substandard speakers and expecting someone to hang them up. But this is unforgiveable. Whoever rigged this was before my time at this District, and should NEVER be allowed to rig another anything overhead. Nor did they understand amplifiers. Four pictures below.
Pic 1: The detroyed cabiner after having fallen. Note the disintegrated particle board cabinet.
Pic 2: Back of destroyed cabinet. Arrows show where eyebolts/nuts pulled out of wet particle board. Also note the 70V transformer.
(2 more pics in reply)
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Two more photos:
1. What passed for "rigging": Two chains around overhead strut (25 ft above floor), with eyebolts backed by a single nut. Also note ugly wiring job. 18awg cable comes in from adjoining Cafetorium amp, then passes on to other speaker.
2. In-wall mixer/amp at the Cafe stage: Two cafetorium speakers are properly connected to 4-ohm direct output. Gym speakers have been connected improperly to 70V output. Other cable from 70V out goes through speaker-to-line transformer to feed Assisted Listening System.
To Do List:
1. Get 25 ft lift.
2. Remove other speaker before it falls.
3. Find a suitable amp to drive replacement speakers (I have a few possibilities in my shop)
4. Upgrade cable.
5. Get structural team to fix leak in roof.
6. Properly rig replacement speakers.
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My goodness, fortunately nobody was hurt. That could have been fatal.
I won't even comment beyond that.
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But it says "pro"...
JR
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I wonder how many other death traps the original 'installer' has created.....
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If you haven't already, prepare final report and also submit it to the district school board. AS Debbie pointed out, there are probably others out there and the the school board will want them corrected.
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Yikes. I hope the area around the other offender has been roped off immediately so nobody walks through it!
This is a perfect example of something that might look just fine from a casual observer being horribly dangerous. Any inspector should have been able to recognize that as an unacceptable hang job and required immediate removal. ANYTHING hung overhead needs to be done with utmost care.
Sadly, you'll see stuff like this ALL over the place. And when you propose doing it right, they'll often just find someone that's willing to cut corners and do it cheaper.
Now, regarding the 70v transformers, I'm not sure I see the issue with that. Other than the wiring being a little messy looking, bolting a transformer to the back of the speaker cabinet isn't the end of the world. Yeah, it would be better to put inside, but I don't see much wrong with it being outside the cabinet as long as it's securely fastened.
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Sadly, you'll see stuff like this ALL over the place. And when you propose doing it right, they'll often just find someone that's willing to cut corners and do it cheaper.
Or they say "it's been hanging up there all this time and hasn't fallen"
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Or they say "it's been hanging up there all this time and hasn't fallen"
Yep - great rationale...
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Now, regarding the 70v transformers, I'm not sure I see the issue with that. Other than the wiring being a little messy looking, bolting a transformer to the back of the speaker cabinet isn't the end of the world. Yeah, it would be better to put inside, but I don't see much wrong with it being outside the cabinet as long as it's securely fastened.
The only problem I have wqith the 70V transformer is that it is connected to the 70V output of the amp that is ALSO already outputting via 4ohm.
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The only problem I have wqith the 70V transformer is that it is connected to the 70V output of the amp that is ALSO already outputting via 4ohm.
Yeah, that's going to come down then to the amp and what kind of load it can tolerate. Some amps are rated to be able to drive a combination of both loads. A little more math is needed to know if it's ok. If there's 4 ohms on the main load though, it's likely that the transformer load would drop the amp below accepted levels.
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Or they say "it's been hanging up there all this time and hasn't fallen"
....Yet.
Had one install where the tech brushed against the old speaker - and it fell (into his arm thankfully). Over time that S hook had slowly expanded until it was balancing on a breath.
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Texas (like many other states) is full of installs like this. I have walked away from a couple over the years where the original install was similar and I refused to take responsibility unless they allowed me to do it properly. I've seen speakers hung with baling wire, nylon rope, jack chain, and even zip cord, using the handles, screw eyes, lag bolts, and once wrapped around the screws holding the corner hardware in place. I wish I could say these were all in the rural areas where there are no inspectors or standards, but at least one was in a major school district. Thankfully that one was actually corrected after i pointed out the poor rigging.