Houston, we have volume controls...

A

Adam Kane

Freshman
Apr 8, 2011
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Working in a funeral home...tearing out all of the old gear (except speakers) and replacing with newer and easier to use gear.

The two pictures attached are from the closet where the rack is located...

13-gang box??

IMAG0189.jpg

Nope.

Just a big slot cut into the drywall, notching at least 80% out of two studs (non load-bearing wall) and a bunch of little hollow wall anchors. Did I mention lots of wire nuts? They home-ran every single speaker...even those all in the same zone/room. So...if one room had 8 speakers, there were 8 wires run into this mess and all connected to the control.

IMAG0197.jpg

All of the above had been eliminated and replaced with a more appropriate zone controller.

The entire job is like this...they paid a fairly large, well-known company (at least around here) lots of money for this system four years ago. What a waste...
 
Re: Houston, we have volume controls...

I'm working on a fairly large distributed system install where the user wants a ton of pretty complicated routing options over a geographical area of about 40 acres (5000' of WestPenn Aquaseal multipair signal cable connecting everything so far), but to "keep it really simple".

Poor construction techniques aside, a wall full of 70v autoformers like that is looking really good now.

Now what is the damping factor over 2200' of 12ga wire? :)
 
Re: Houston, we have volume controls...

Adam Kane said:
Bennett,They used wp 291 for all speaker wiring...
Click to expand...
Why bother with two cables on the job if you can use one for everything? Helps with being able to purchase cable and autoformer volume controls in bulk quantities, thus getting better pricing and underbidding your competition. AT least that's how such things seem to work.

It may not be the most cost effective approach but there are times I have homerun cabling for other reasons, so that doesn't necessarily bother me. However, I almost hate to ask, but did the blank one and two gang plates on the right have some purpose or was it apparently that thirteen was someone's lucky number or they were going for a record or something?
 
Re: Houston, we have volume controls...

True story, recently I was involved in a project where the "consultant" had insisted that all 70 volt speakers be on home run wiring to the amp room using 14 AWG cable! You should have seen the humungous cable bundle of 30+ speaker cables coming to the rack!!! It was all ripped out and wired properly like a normal 70 volt system should be. The client was not pleased having wasted about 20k+ on union labour and materials with this snafu. All kinds of similar screw-ups on this job!
 
Re: Houston, we have volume controls...

Arthur Skudra said:
True story, recently I was involved in a project where the "consultant" had insisted that all 70 volt speakers be on home run wiring to the amp room using 14 AWG cable! You should have seen the humungous cable bundle of 30+ speaker cables coming to the rack!!! It was all ripped out and wired properly like a normal 70 volt system should be. The client was not pleased having wasted about 20k+ on union labour and materials with this snafu. All kinds of similar screw-ups on this job!
Click to expand...

Why rip it out and rewire it?
 
Re: Houston, we have volume controls...

Brad Weber said:
Why bother with two cables on the job if you can use one for everything? Helps with being able to purchase cable and autoformer volume controls in bulk quantities, thus getting better pricing and underbidding your competition. AT least that's how such things seem to work.

It may not be the most cost effective approach but there are times I have homerun cabling for other reasons, so that doesn't necessarily bother me. However, I almost hate to ask, but did the blank one and two gang plates on the right have some purpose or was it apparently that thirteen was someone's lucky number or they were going for a record or something?
Click to expand...

Brad,

I think the extra plates were there to cover the extra length of un-used "technical slot" that was cut most likely to facilitate in jamming that mess into the wall. I should have taken a picture with everything opened up. The wad of wiring was MUCH bigger than what it looks like in that picture.

Every one of the speakers simply had the 1/2" ko plug twisted to the side with the wire pulled through...no bushing/connector. Found three speakers that quit working because of a dead short between conductors. I think the fact that the system is never required to produce any substantial output is probably the only reason the amp wasn't cooked.

Existing fixed LCD mounts were changed to articulating arms. In the process of doing that, we discovered that most of the wall brackets were held only to the drywall with small toggle bolts...nothing into the studs. These were all fairly large screens (40"+)...one was already quite a bit out of level...the rest had cracked drywall behind them. Can't believe none of them fell.

The same company that did the A/V also installed the alarm system in there. The genius ran all the cabling (LOTS) in mid-air, right over/thru the only attic access in the building. Having to climb through a web of that crap in a HOT HOT attic every time you go up/down is fun. At least if he ever needs to service that stuff, it's all easy for him to get to...never mind anyone else.
 
Re: Houston, we have volume controls...

Milt Hathaway said:
Why rip it out and rewire it?
Click to expand...
Because there was no room left in the conduit for the main sound reinforcement system wiring, the bundle going into the rack would have been about a foot in diameter! Furthermore, it would have been one heck of a huge junction box to terminate all those connections, and not enough space in the rack room for it! The AV contractor did not do the wiring installation (union constraints), and wanted the job to be done correctly so that a thread similar to this wouldn't haunt him in the future! ;)
 
Re: Houston, we have volume controls...

Arthur Skudra said:
True story, recently I was involved in a project where the "consultant" had insisted that all 70 volt speakers be on home run wiring to the amp room using 14 AWG cable! You should have seen the humungous cable bundle of 30+ speaker cables coming to the rack!!! It was all ripped out and wired properly like a normal 70 volt system should be. The client was not pleased having wasted about 20k+ on union labour and materials with this snafu. All kinds of similar screw-ups on this job!
Click to expand...
Arthur Skudra said:
Because there was no room left in the conduit for the main sound reinforcement system wiring, the bundle going into the rack would have been about a foot in diameter! Furthermore, it would have been one heck of a huge junction box to terminate all those connections, and not enough space in the rack room for it! The AV contractor did not do the wiring installation (union constraints), and wanted the job to be done correctly so that a thread similar to this wouldn't haunt him in the future! ;)
Click to expand...
While it is not necessarily my standard approach for 70V distributed systems, I have had projects where each speaker was run individually so that a) no single speaker or cabling failure affected more than one speaker, b) testing and servicing was simplified and c) speaker zones/groupings could be easily modified or revised. I don't know if that was a legitimate issue on the project referenced or not, however, it does make me curious as to what was the basis for deciding what was "wired properly like a normal 70V system should be" if that is not what was initially designed?

According to my calculations you could fit 30 typical 14AWG, plenum rated twisted pair lines in either a single 2-1/2" conduit or two 2" conduits. And using Phoenix DIN type feed-throughs or even screw terminal strips rated for the voltage, current and AWG involved the related connectivity would easily fit on the inside of a side panel of a standard rack. There has to be more to this as even if there was not a compelling reason to home run each speaker, I also don't see anything that necessitated changing the wiring. And without some good basis for a change it seems that the AV Contractor should have planned to have installed everything the way it was initially designed.
 
Re: Houston, we have volume controls...

Brad Weber said:
While it is not necessarily my standard approach for 70V distributed systems, I have had projects where each speaker was run individually so that a) no single speaker or cabling failure affected more than one speaker, b) testing and servicing was simplified and c) speaker zones/groupings could be easily modified or revised. I don't know if that was a legitimate issue on the project referenced or not, however, it does make me curious as to what was the basis for deciding what was "wired properly like a normal 70V system should be" if that is not what was initially designed?

According to my calculations you could fit 30 typical 14AWG, plenum rated twisted pair lines in either a single 2-1/2" conduit or two 2" conduits. And using Phoenix DIN type feed-throughs or even screw terminal strips rated for the voltage, current and AWG involved the related connectivity would easily fit on the inside of a side panel of a standard rack. There has to be more to this as even if there was not a compelling reason to home run each speaker, I also don't see anything that necessitated changing the wiring. And without some good basis for a change it seems that the AV Contractor should have planned to have installed everything the way it was initially designed.
Click to expand...

That's what I was thinking when I asked the question. If the bundle cannot penetrate the rack, simply add an external gutter with a screw terminal strip in it. Testing, maintenance, and future expansion capability is maintained, and the client doesn't needlessly pay for a full system rewire.

Someone made a nice labor bonus though, so who am I to complain.
 
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