Test speakers and rooms with a frequency sweep

The job

Play 20 Hz → 20 kHz through the system and listen: rattles appear as buzzes at specific moments, room modes boom at their frequencies, and the top of the sweep tells you where the tweeter (or your hearing) gives up.

Set the sweep

Start 20 Hz, end 20 kHz, 10–30 seconds, logarithmic curve (equal time per octave, like hearing works). Sine for clean testing; square/sawtooth only if you want harmonics on purpose. Generate, download the WAV, play it through the system.

• A logarithmic sweep spends the same time in every octave — a linear one rushes the bass.
• Keep the level modest. Full-scale sweeps into tweeters are how tweeters die.

Reading what you hear

Buzzes that track the sweep = loose panels or driver rub. A room mode is a note that suddenly booms and decays slowly — walk around and it gets louder in the modal spot. What you hear above ~15 kHz is mostly about your ears, not the gear.