Hello all, The incredible happens. The electronics of the 'Lampadario' at the Casa del Suono in Parma consists of a rack with an RME ADI468 converting MADI to 8 ADAT outputs, 8 Behringer ADA8000 converters, and 8 QSC amplifiers of 8 channels each. The rack was wired (very neatly) by a firm specialising in this sort of work. When I installed the software four years ago, I found out that 25 of the 64 channels had their phase inverted. For one of those it was an error in the speaker wiring, which was easy to correct. The other 24 corresponded exactly to 3 groups of 8, and the speaker wiring was OK. I assumed that the cables between the ADA8000 and the amps were to blame - this is a non-standard cable which had to be hand-made by the whoever did the wiring. If two technicians had worked on that, they could have had different ideas of what were the correct connections. Since I didn't want to take the rack apart, resolder 24 wires and put it all back, and since there was only one SW app driving the installation at that time, those 24 inversions were corrected for by that software. So far so good. Recently I re-measured the IRs of the whole thing. There were again 24 channels out of phase. But not the same ones. One of the groups of 8 had turned in-phase, and another one was now inverted. 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. The incredible happens. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
