Boomy bass usually comes down to one of three things: the subwoofer is simply too loud, one bass note swells at your seat while the others do not, or the bass rings on after the note has stopped. They feel similar from the sofa, but they look different on a measurement and they need different fixes. Work out which one you have first, then change one thing at a time.
Written from Room EQ Wizard’s own help pages, miniDSP’s microphone advice and the setup guides elsewhere on this site. The graph is a made-up example, not a measurement of any room.
Three kinds of boom
**Too much bass on everything.** Dialogue sounds thick, music sounds heavy and every explosion is too much. The usual cause is the subwoofer’s level, or a setting that adds bass on top of it.
**One note that swells.** A bass line sounds uneven: most notes are fine, one or two jump out. That is usually the room. At certain frequencies the sound reflecting between the walls adds up at your seat, and a measurement shows it as a narrow peak.
**Bass that lingers.** A kick drum or an impact seems to hang on after it should have stopped. The same room resonances that cause a peak also take longer to die away, which shows on a decay view rather than the plain response.
**Something that rattles.** A buzz from a cabinet door, a picture frame or the subwoofer’s own feet is not boom at all. Play a slow bass sweep and walk round the room listening for it: a measurement at the seat may show something odd, but it cannot tell you which door or frame is buzzing.
Rule out the settings first
Before you measure, write down every setting that touches the bass: the subwoofer’s level on the receiver and the volume knob on the subwoofer itself, the crossover and whether your speakers are set to Small or Large, the room correction setting, any bass boost, dynamic EQ or night mode, and the subwoofer’s phase and its place in the room. Then change one thing at a time, or you will not know which change helped.
If you turned the subwoofer up after the receiver’s calibration, put it back to where the calibration left it before going further. The subwoofer integration guide covers the crossover, level and timing in order.
Change one thing, measure again, and only then change the next.
Measure safely
Start quiet. REW’s help says measurements are usually made at about 75 dB SPL, that its test signal starts at -12 dBFS, and that very loud test signals can damage speakers and ears. Use its Check Levels step with the receiver’s volume low, then raise it carefully. If the microphone reading stays low, do not keep making the test signal louder: check that REW is using the right input, the right calibration file and a sensible input level instead.
Watch for clipping. A big room resonance can push the microphone input past its limit, and REW warns when there is less than 6 dB of headroom. If that happens, lower the sweep level, the receiver’s volume or the input level, not the other way round.
Put the microphone at seated ear height in your usual seat, with its calibration file loaded. For miniDSP’s UMIK-1, miniDSP recommends pointing it at the ceiling with the 90° file when you measure a home cinema with speakers all around the seat, and the 0° file when you point it straight at a single speaker up close; for Dirac Live it says always use 90°. Other microphones have their own advice. The step-by-step measuring guide covers the whole setup.
Read the bass response
Measure the subwoofer on its own from the main seat and look at the range up to about 200 Hz. One-note boom shows as a narrow peak, several decibels above the bass around it, at one frequency. The REW Analyzer on this site lists the biggest peaks for you, measured against the trend around each one.
A subwoofer measured alone cannot show whether it is too loud for the speakers. For that, measure a front speaker alone too, at the same volume and from the same microphone position, and lay the two over each other. If the subwoofer sits well above the speaker where their ranges overlap around the crossover, its level is set too high. The REW Analyzer’s Subwoofer integration view puts the two side by side.
The room mode calculator predicts which frequencies your room’s size favours. Its predictions come from an idealised room with rigid walls, so treat them as a guide to where to look, not as proof: a real room’s walls, windows and furniture shift them.
Move the microphone, then the subwoofer
Measure again with the microphone a short step, 30 to 50 cm, to each side of the first spot, and at the other seats you use. A room peak changes from place to place, which tells you two things: position matters, and the problem may be smaller or larger at the other seats. Aim for bass that is even across the seats you use, rather than one perfect line at one seat.
Moving the subwoofer changes which resonances it drives. The subwoofer crawl in the integration guide is the quickest way to find a better spot: listen for the most even bass, then confirm it with a measurement. Moving the seat a short way forward or back can help as much, since a room peak is stronger in some places than others.
If the boom sits near your crossover frequency rather than below it, the subwoofer and speakers may be adding up badly there. That is a timing question; the subwoofer delay calculator converts a measured delay into the distance setting your receiver uses.
When the bass lingers
REW’s waterfall shows how each frequency dies away over time, slice by slice, and its spectrogram shows how the frequency content changes over time. A resonance that rings shows up as a ridge that lasts longer than the frequencies around it, usually at the same frequency as a peak.
Do not judge the bass by an RT60 figure. REW’s own help says RT60 is typically not meaningful below a few hundred hertz in rooms of domestic size, and points to the decay views instead.
Fix it in this order
**Settings first.** Put back the level and any bass boost you added, and check the crossover. It costs nothing and is easy to undo.
**Position next.** Try other subwoofer spots and small seat moves, measuring each one.
**Then EQ, as cuts.** REW’s help says an equaliser can help tame peaks, but sharp dips are very sensitive to position and EQ can only ever be part of the solution. Cut the peak; do not try to fill a deep dip with boost, which spends amplifier power and fixes it at one spot at best. Room correction in the receiver does this kind of job too; measure after it runs.
**Then treatment that reaches the bass.** Low frequencies need thick, deep absorbers or purpose-made bass traps. Thin decorative panels do little down there; the acoustic panels guide explains what reaches how low. If the real complaint is bass reaching the neighbours, that is isolation, not treatment: see Big sound, thin walls.
After every change, measure again with the same level, the same microphone position and the same settings, so the before and after can be compared. Then listen to something you know well at your usual volume.
