Re: 131st AES Convention Observations
I couldn't find it on their website or in the manual in a quick search, but I've heard it right from the horse's mouth. the whole point of the groups is that theoretically if you use channels that are all in the same group they are coordinated to avoid IMD problems.
that's why (on the ULX at least) there's a group scan function that looks for the group with the most open channels. this makes a great starting point for someone who doesn't have a scanner or prediction software
of course, the group scan doesn't do any math, nor any scanning (other than that group's frequencies) so Drew's problem could easily be from a nearby TV transmission creating IMD with transmitter A that lands on Frequency B. with transmitter B off the receiver ignores the noise because there is no pilot tone. both transmitters on and you'd hear the artifacts, turn A off and the problems go away as well. move away from the receivers and the IMD is less significant..
so obviously the groups aren't flawless, just a good starting point for a small system but if you're setting up more than a half dozen channels its probably best to get some software and a scanner.
Jason
