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The Bad Examples Page...
Things we don't like to
see at a final inspection!

The photos you are about to see are real. We've elected to use these photos as an informative method to show what not to do in sound system installations.

a rat's nest of dangling wires and widgetsWe often get asked to come in and look at existing sound systems in churches, schools and arenas. Often these systems are several years old, have had numerous changes and alterations made to them, all sorts of baling wire and binder twine solutions by people with various skill levels. The wiring is often a mess, things are dangling from wires in the rack, and there is equipment placed any old place, including just resting on top of other pieces of equipment. Often it is from these accumulated "repairs" that the system falls over dead. These photos could be from just such an aged installation, they exhibit all the things that make a techie cringe, and yet this isn't what you think it is. Read on...

more rat's nest of dangling wires and widgetsThese are photos from a brand new installation, and this was the way we found it when we arrived to commission the new system. These photos show nearly every single incorrect way of implementing the cable management in an equipment rack, the labelling, the equipment fabrication and documentation, the termination, and the cable splicing (Cable Splicing in an equipment rack? Wait a minute....). Note the stick on modules attached haphazardly to the side of the rack in the photo above. Also note that there is a transformer dangling on the connecting wires, with no other support. Note the inappropriate use of a nylon terminal strip free floating in the air behind a transformer mounting panel.

custom construction does not have to look amateurish, but it often does.It is often necessary to custom fabricate equipment to mount various special devices and switching components. Shop drawings should be submitted prior to fabrication to avoid inappropriate custom fabrication, such as this example. This mystery box, sitting loose on top of a piece of equipment, is missing such basics as grommets for wire exits, and features felt pen labelling of all the terminals.

things terminated on a flying terminal stripThis is not the way to mount a terminal strip in an equipment rack, using a skyhook to hang it in free air, and having a small relay attached to the terminal strip too. At least no one will be bothered by the sound of relay actuation, the vibration isolation is superb. Note how close this terminal strip is to the side of the rack where several convenient mounting points would have been available to fasten the strip in place.

note the in-line splices in cable and the transformer leads neatly dressed

It is such a bad idea to use in-line splices in shielded cables, especially when it would have been very easy to terminate the two cables on the connector on the source equipment. Note the transfomer leads that are unterminated are neatly pointed up in the air where they can do no harm by touching nearby surfaces.

cable terminations

Sadly this sort of workmanship problem isn't an isolated case. Here's an example from yet another project of BEFORE and AFTER cable terminations to a wall plate. The terminations had poor solder joints, cold solder joints, no cable labels, the cable was not properly prepared for termination and the drain wire used the outer cable jacket and had a wide variation of exposed length, the video cables were crushed at 90 degree angles where they were squashed into the backbox. The panel at right is after the deficiencies were cleared, the cable labels are in place, the ends of the cables were prepared (the heat shrink on all the inner pair wires was a bit of overkill, we'd be happy as long as the drain wire is properly insulated), the drain wires were equipped with a correct diameter insulating sleeve, the BNC's were changed to 90 degree connectors and there is some order to the cable.

To maintain a balanced viewpoint, we happily present the Good Example page. On the Good Example page we will display photos of nicely done installations where the contractor managed to avoid the pitfalls shown on this page. We're hoping that the good examples become more prevalent than the bad examples.



Mc Squared System Design Group, Inc Mc Squared System Design Group, Inc
323 - 901 West 3rd Street
North Vancouver, BC V7P 3P9
Phone 604 - 986 - 8181