On Mon, Jul 01, 2013 at 09:29:53PM +0000, Fons Adriaensen wrote:
The only thing that has happened to the installation
over
the last years is that some of the Behringers failed (power
supply blown up, one per year on average) and were replaced.
So I checked those separately. And yes, some of them had their
output phase inverted w.r.t. the others. Apparently the thing
exists in two versions, but apart from measuring there's no
way to tell which is which. So I'll have to recheck things
each time any of them are replaced again. Thank $GOD we didn't
use those for the WFS system.
This is appalling, but I'm aware it happens sometimes. I've
observed a similar thing with Chinese condenser microphones,
including some relatively expensive ones. Now I always check
polarity against a known good mic whenever I buy a new one.
Looks like I'll also have to start checking other gear.
Thanks for the warning.
John