Speaker placement: the free upgrade most rooms are missing
The same speakers can sound muddy or magical depending on where they sit. Placement costs nothing and moves the needle more than most gear swaps.
The front three: triangle, height, toe-in
Your left and right speakers and your seat should form roughly an equilateral triangle, with each speaker angled 22 to 30 degrees off the center line and the tweeters at seated ear height — around 37 to 40 inches. Angle (“toe in”) each speaker toward the main seat to sharpen the stereo image. Pull them at least a foot out from the front wall if the room allows; speakers jammed against a wall pick up boundary boom that no volume knob fixes. The center channel goes directly below or above the screen, aimed at ear height — it carries most of the dialogue, so its placement is not the place to improvise.
Surrounds and heights
In a 5.1 layout, the surrounds belong to your sides, 90 to 110 degrees around from the screen, mounted a foot or two above ear level so they envelop rather than point at you. In a 7.x layout the extra pair goes behind you at 135 to 150 degrees. Atmos height speakers work best in-ceiling, slightly forward of and behind the seat; up-firing modules are the fallback, and they need a flat, ordinary-height ceiling to bounce off. Symmetry matters more than perfection — matched angles and distances left-to-right beat ideal angles on one side only.
The subwoofer crawl
Bass is the one thing you can’t place by eye, because the room dictates where low frequencies stack up or cancel. The classic trick: put the subwoofer at your listening position, play bass-heavy music, and crawl around the edges of the room — where the bass sounds smoothest and fullest is where the sub should live. Corners give the most output but can sound boomy; the crawl finds the honest answer for your room. Ten minutes on your hands and knees routinely outperforms a hundred dollars of extra subwoofer.