This may be elementary to some, but I had an issue last weekend that I'd never run into before with my DL32R.
I was getting some low feedback onstage (around 100 Hz), and I didn't understand because I was using the same monitors and settings as the other gigs, I just added another stage monitor for the dummer (Aux 5).
I fixed it with EQ at the gig, but I realized days later that Aux 5 was set to the default - Pre Fader, instead of Pre DSP like Aux 1-4. And, you guessed it, the drummer wanted the EQ on his kick to include a nice peak at around 100 Hz. When your Aux is configured for Pre-DSP, the channel EQs are FOH only.
