I just purchased two new L1 compact stacks and a Soundcraft ui16 mixer for my intimate coffee shop venue. If I plug guitar (fender strat) and mike (shure sm58) in the L1 and daisy chain the two L1 stacks together, I get zero humm/buzz. The sound is crystal clear.
when I plug the soundcraft mains in the line-in on the L1’s, without even plugging in an instrument/mike in the mixer, I get a buzz/humm the instant I increase the mains on the mixer...
I tried different electrical outlets, I tried plugging everything in the same outlet with the help of a power bar. I’ve tried different audio cables. I am out of ideas?
It's not unusual for peripheral equipment to introduce a buzz. It appears you have checked all the usual suspects and not found a solution.
Sometimes careful gain staging can diminish the hum to an acceptable level.
I assume you are following the suggestions in the Compact user guide. As I write this I do not recall suggested levels but I will look around and link to info if I can find something helpful.
Thanks. Seems like the trouble was not coming from the L1's. We tried 3 sets of audio cables and finally, tested another mixer and everything went away. It was a mix of one faulty cable in part but most of our hum was coming from the mixer itself. I then tested the mixer with another set of powered speakers a friend lent me and the same buzz appeared...
Thanks so much guys for getting back to help us out 🙂