- Don't put your seating right against a wall, back or side. This is the worst place in any room for smooth frequency response.

- Don't put ANY speaker or sub that isn't specifically designed to be built in inside a cabinet or build it into a wall. You'll drastically change the response curve. The crossovers are specifically designed for a specific frontal area on the cabinet.

- Don't put a sub in a corner if you can help it. Almost never is this even close to the best place for a sub. While it will yield the most sheer output, it will also yield the least smooth frequency response curve.

- Don't force too big a screen into a room. This causes you to compromise on seating and speaker positioning. Set the seating right FIRST, then look at the appropriate screen size for that viewing distance that still allows good speaker placement.

- Don't run your main speakers full range. Get a sub and let it do it's job. Almost never is the best place for imaging and locking sound to the screen a good place for smooth bass reproduction. Cross your speakers at 80Hz (this can vary slightly) and put your mains where they need to be. Then you can move the sub around to find the best place for bass response without messing other things up. The side benefit is taking off a huge load from your mains and the amp that's driving them - leaving more headroom for increased dynamics without clipping the amp.