Where I would start make sure your reciever is matched to your speaker size, to do this you have hook the reciever up to a tv and open up the power and tell the reciever that you have large or small speakers and that will funnel the power were it needs to go. It may also ask how far each speaker is in feet from the reciever and believe me it makes a world of a difference. Dont skimp on wire ethier for long runs, for the EQ start setting make the EQ smile at you, and you can fine tune your sound from there. What I always do for the sub, if your reciever will let you turn the crossover freq off, do it and adjust on the sub. If you want to use the gain for sub volume in the reciver thats up to you. In this CASE I would not use the mic to dial in the sound, go radio shack and purchase a decibel meter and do it that way its more acurate and you can sit in your favorite spot in the room and adjust the reciver to were you like it. After you do this I'm confident this will fix your problem.....