Re: Houston, we have volume controls...
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.
