When I mix at my church the guitars always seem to sound like nothing but treble. As if they had grabbed both the mid and bass knobs and turned them all the way down and cranked the treble all the way up. But then when I stand on stage with the amp blowing in my face, it sounds great. Nice sweet highs, low end punch, everything I could ask for from guitar tone. So there's some sort of disconnect going on. When I'm standing in the sound booth the guitar tone sounds harsh and piercing, when I stand on stage in front of the amp it sounds great. Perhaps something to do with the reflections in the room? PS the guitarist has just a 15 watt combo on a stand pointed at his face. He's really trying to do his part. I'm just trying to get the sound he's hearing to translate to the audience, and it hasn't worked out well so far.