Unless I really know and trust the sound engineer - I run a post-eq signal from my GK MB500 to one channel of my PSM 200 (mono but 2 channels), then through to the PA. Other channel is aux feed from the FOH mixer. I eq my bass for my IEM mix - nothing so drastic that it would give the engineer an unusable signal though. I ditched the SE215 buds for Westone UM 30 Pro 3-drivers - big difference.