BSS Prosys 8810

[Lee Douglas]

I've got a BSS Prosys 8810 in an large multi zone outdoor sporting goods store install the has recently started exhibiting strange behavior. It has a music source, two mic inputs and one phone page input, all analog (no cobra net) that's output to seven Crown CTS2000 amps. I was called in to diagnose a music drop out issue, which I knew was one of the mic sources ducking the music as it had been programmed to do. Somebody else had gotten into it and started changing things and I had to get it back to square one, which I was able to do with a scene recall and reinitialization of the network music source. Except now when I bring the music source up it starts to cyclically feed back in little spikes which show on the meters in the software as well as on the amps. So I removed all of the mic and phone inputs from the back and muted all of the inputs except the music source. It still does the feed back thing and once I isolated it, when I push the input it goes into what sounds like a steady feed back tone, varying with the virtual fader, but not run away. With no open mics on the system. I can't think of anyway in programming to feed an output back into an input on the system to cause the loop. I'll call Crown in the morning and go over it with them, but I'm just thinking out loud and wondering if you gentlemen have an thoughts. Thanks.

 

[Craig Hauber]

Re: BSS Prosys 8810

I had a situation once where the 70V output of the amplifier was being picked-up by the line-input wiring between the music source and the dsp (a ZonePro) and causing something similar to what you're describing.

A long RCA unbalanced run was zip-tied to a bundle of speaker wire a long ways through an attic. Whether the crosstalk was the actual problem or not, it went away after separating the lines and running balanced (using a Henry Eng. Matchbox).

You might try disconnecting the music input from the DSP and cranking it up and see if the problem is still there. Then try running with an iPod/phone/player of your own patched into the DSP directly with a known-good cable.

 

[Lee Douglas]

Re: BSS Prosys 8810

Thanks Craig. The music source(s) are mixed at the front of the store and then sent around 800 feet to the back of the store where my racks are in the network room. I'm sure those lines interweave with my nine outputs somewhere along the way. Unfortunately, it's not my install, it's just my problem as of three years ago.

Anyway it turns out the inputs are going bad on the DSP. I switched the inputs around and reprogrammed and all is well with their world again. At least until the other inputs go bad. We went through this three years ago when they didn't want to pay (and never did) for the repair on the primary DSP. This is the secondary. I can only imagine what a stupid emergency this is going to be when number two goes down, despite the six warnings that I personally delivered.