The seven-step calibration
1Place your speakers correctly
Form an equilateral triangle between the two front speakers and your listening position, with tweeters at ear height and speakers toed in toward you. Keep speakers at least 30 cm from walls to reduce boundary bass boost; surrounds go slightly above ear height, beside or just behind the seating.
2Verify every channel works
Play a left-only and right-only test signal and confirm each speaker plays the correct channel. Swapped left/right cables are among the most common home theater faults.
3Check speaker phase
Play identical in-phase and out-of-phase signals. Correct wiring sounds fuller, bassier, and centered; if the inverted signal sounds better, swap + and - on one speaker.
4Balance channel levels
Sitting in the listening position, play a panning test tone and adjust balance/trim until the sound sits exactly in the center. Use an SPL meter app at 75 dB per channel for finer accuracy.
5Place and cross over the subwoofer
Try the "subwoofer crawl": put the sub at your listening position, play a bass sweep, and crawl along the walls to find where bass sounds smoothest - that is the sub's spot. Set the crossover about an octave above your main speakers' low-frequency limit, typically 80 Hz.
6Hunt room modes with a sweep
Run a slow 20-200 Hz sine sweep at moderate volume. Frequencies that boom or vanish reveal room modes; move the sub or seat 20-30 cm and re-test, or tame the worst peaks with EQ cuts.
7Fix lip-sync delay
Wireless speakers and TV processing add audio latency. Measure your system's delay, then dial the compensation into your TV or receiver's audio delay / lip-sync setting.
Why subwoofer placement matters more than the subwoofer
Below about 200 Hz, your room dominates what you hear. Bass wavelengths (a 40 Hz wave is over 8 meters long) reflect between parallel walls and form standing waves - room modes - that boost some frequencies and cancel others depending on where the subwoofer and your ears sit. The same subwoofer can sound boomy, thin, or perfect in the same room purely based on position.
That is why the subwoofer crawl works: by placing the sub at ear position and listening from candidate locations, you sample the room's transfer function in reverse. Corners give maximum output but excite every mode; positions partway along a wall usually trade a little level for much smoother response. Verify each candidate with a slow 20-200 Hz sweep and our subwoofer test, listening for even loudness across the sweep rather than maximum boom.
Common mistakes
- • Skipping the phase check. One swapped speaker wire silently ruins bass and imaging - it takes 30 seconds to verify.
- • Crossover set too low. Small satellites cannot produce 50 Hz; sending it to them instead of the sub just loses it. When in doubt, 80 Hz.
- • Subwoofer volume set by demo scenes. Calibrate with test tones to match the mains, then adjust taste by 1-2 dB - not 10.
- • Balancing from the wrong seat. All level and balance judgments must happen at the actual listening position.
- • Ignoring lip-sync. Wireless surrounds and soundbars commonly add 20-100 ms; measure it and set the delay once instead of being vaguely annoyed forever.