Just last weekend, our band used IEMs for the first time at an all-weekend rehearsal. We ran an output (Line Out) from the main Mixer, to Behringer HA400 Mini Headphone amp / mixer, out to x4 sets of the KZ AS10s. It sounded fantastic. We were playing x2 Electro Acoustic guitars, x3 Vocals, Keys, and my P-Bass via the Pod Go (I also use a Helix Stomp).