@ScottV posted:@gunrunnerjohn a couple of questions on the 4 channel relay...
can you have more than 1 location playing sound at the same time?
can you independently adjust volume for each location?
what's the output power and speaker impedance (didn't see it on the linked description) ?
thanks for the post!
Scott,
There is only one audio source, so you can only have one location playing at a time. Obviously, instead of the 4-channel relay receiver, you can just use multiple sound modules. 
The multiple location idea was drawn up because someone asked about that option.
It's easy to add volume adjustment to the individual feeds, a 50 ohm pot in series with the speaker does the job.
The sound board output is 3 watts max into an 8 ohm speaker. I specified speakers with a 2W to 5W rating as reasonable choices.
