Loudspeaker Listening Test Suite

A continuously rising tone or noise band that walks energy across the spectrum. Listen for: sudden loud/quiet spots (frequency-response peaks & dips), notes that "hang on" after they pass (resonances/ringing), and buzzes at specific pitches (rub & buzz, cabinet rattles). The two noise-band widths smear the excitation: 1/3-octave reveals narrow resonances, 1-octave gives a smoother room-like balance check.

Short isolated events stepping up the scale. Listen for: clean attack and decay vs. "smearing" (poor transient response, stored energy). Gaussian sine grains probe time/frequency clarity; noise-band bursts reveal time-alignment and energy storage per band; filtered Dirac pulses are band-limited clicks that expose ringing, pre/post echo and driver integration. Each burst sits at a stepped frequency so you scan the whole range.

Full-band noise with a single deep notch that sweeps across the spectrum — the inverse of a tone sweep. Listen for: the moving "hole" of silence. Your ear/brain tracks the notch smoothly when response is flat; if the notch seems to jump, widen, or disappear at certain frequencies, the speaker has a peak, dip or resonance filling it in. Extremely sensitive to narrow anomalies.

A fixed high tone (default 12 kHz) paired with a second tone that sweeps 50 Hz → 10 kHz. A perfect speaker reproduces only those two tones. Listen for: any new low pitches that appear and move — these are intermodulation difference tones (f_high − f_low) created by non-linearity, Doppler/FM distortion from large cone excursion, and overload. The more you hear besides the two pure tones, the worse the IMD.

A tone whose pitch wobbles gently around a centre frequency. The frequency spread averages out sharp room standing-waves, giving a steadier loudness than a pure tone. Listen for: a smooth, even warble — roughness, beating or amplitude pumping indicates a tight resonance, while stepping the centre frequency lets you judge low-end evenness room-by-room. Classic SPL / bass-evenness check.

Many sine tones summed at once. By choosing their phases the crest factor (peak-to-RMS) is set low (music-like, flat) or high (spiky, demanding). Listen for: at high crest factor, transient peaks that should pass cleanly — compression, clipping or "spitting" means the amp/driver can't follow the peaks. Comparing low vs. high crest at equal RMS reveals dynamic-headroom and thermal-compression behaviour. Spread tones expose intermodulation as a "dirty" haze.

A very low subsonic tone (drives large cone excursion) played together with a clean high-frequency signal that the same driver or a tweeter must reproduce. The subsonic tone also modulates the treble level ("pump"). Listen for: the treble wobbling in pitch (Doppler/FM) or pumping in loudness as the cone heaves, plus port/suspension noise, rub and bottoming. A brutal test of woofer linearity and excursion limits.