"Owain"


(2) It is likely in a work scenario with this sort of distance that you
premises have 3-phase electricity (415V between phases) and you would be
supplying different sets of speakers from different phases. This has
electrical safety implications.


** Absolute bunkum.

All 3 phases have a common neutral which is linked to ground at the distro.



(3) Unscreed untwisted cable is unsuitable for line-level audio
distribution at these distances.


** Not if properly transformer balanced at the drive end and each take off
point.

Running the audio line at a level of say 10 volts would help a lot too.




........ Phil