My bass is boomy and drowns everything. How do I fix muddy bass?

The room and the settings, almost never the subwoofer. Boomy bass is a placement and level problem in nine out of ten rooms we visit, so do not shop for a new sub yet.

The order I fix it in:

Placement. Pull the subwoofer out of the corner. Corners excite every room mode at once, which gives you maximum quantity of bass and minimum quality: one or two frequencies boom, everything else disappears. Our placement answer describes the crawl method (sub at your seat, you at the candidate positions, listen for even bass) and it remains the cheapest upgrade in audio.

Level. Auto-calibration tends to set subs hot, and hands push them hotter over the following weeks. Drop the sub trim 3 to 4 dB and live with it for a day before judging. Bass that impresses in the first minute is usually bass that tires you by the end of the film.

Crossover. Front speakers set to Large that should not be, or a crossover set high, hand the sub a range it should not be handling and the mids get thick. Bookshelves and small floorstanders go to Small with an 80 Hz crossover; let the sub do only the low end.

The seat. Sitting hard against the back wall puts you in a bass pile-up, because pressure maxes out at room boundaries. Even 30 cm off the wall changes what you hear. The sofa is not fixed to the floor, however much it feels like it after a long day.

Phase. Flip the sub's phase switch between 0 and 180 and keep whichever sounds fuller at the crossover region. Two seconds, no cost.

Where does the rule stop mattering? When all five help but none cures. Then the room's own dimensions are ringing at specific frequencies (room modes), and no trim knob fixes that. That is what measured calibration and, in stubborn rooms, acoustic treatment exist for. We do the measured version as a paid service; a photo of the room and sub position tells us quickly whether you are still in the free-fix zone or past it.