Is it possible to use armor cable 14/2 in PABGM system?

PABGM, like public address background muisc? You can power it with 14/2 cable but that's it no speakers, mics or anything else. How many amps does your system pull?

Actually we are going to use it in a 31 storey building, with 5 speakers per floor and 10watts t0 15watts per speaker. It was a mistake that the ceiling comes first before the engineers realize to install the said system. So in order not to ruin the ceiling and avoid a big cost impact, it was an advise by the contractor of the system to use armor cable 14/2. thanks!

So are you saying he wants to use 14/2 armored cable for speakers?

Electrically and code wise, should be no problem. I suggest you use #12-2 MC cable.

The audio vendor should agree that a larger wire will reduce impedance, due to the size of the building.