Many may not realize it. But your room is the biggest audio component in a home theater setup. It will make the most difference to the sound. Do it right, and you will get natural balanced sound that you will enjoy indefinitely. On the other hand if the room is not suitable for audio playback, no matter how much you spend on a home theater or sound system it will not sound good.
Granted, there are some things in the room that you can’t change or have no control of, for eg the room’s dimensions. But if you are looking for a new home or building one, you might want to pay attention to how room dimensions affect acoustics, especially if your AV room is small. All rooms have peaks and nulls at low frequencies below 100Hz. This has a profound effect on the way low frequencies for movies and bass in your music will sound. If your listening seat is where low frequencies peak you will get severe bass boom which can be downright uncomfortable and definitely fatiguing if you are listening to music or watching movies for an extended period. Generally avoid a square-sized room if you want good bass.
If you can’t have the luxury of changing room dimensions, the next best option is applying room acoustic treatments. Some of these are common sense and inexpensive. Like placing a thick rug between your screen and your listening seat. Thick curtains will help to contain bass boom and large canvas paintings on the walls will help to reduce high frequency fatigue.
If you have the budget for professional room acoustic treatment here are some recommendations: