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Browse ProductsThree instruments we use in the workshop, rebuilt for the web. Everything runs locally on your device with the Web Audio API: no audio is uploaded, and nothing leaves your browser except an anonymised test score if you choose to submit one.
A calibrated signal generator for controlled cable conditioning (burn-in). Choose a program, set a level, press play, and leave it running. The session persists in this browser, so you can close the tab and resume later.
The sweep is a logarithmic sine from 5 Hz to 40 kHz (the top is clamped to 90% of your playback Nyquist, so at 44.1 kHz it reaches about 19.8 kHz), quantised so the loop point lands on an exact integer number of cycles and repeats with no click. The pink noise program uses a Paul Kellet style IIR filter over white noise for roughly equal energy per octave, crossfaded at the seam for the same reason. Red noise integrates white noise through a leaky integrator for a bass-weighted spectrum. The MLS program is a maximum-length sequence from a linear feedback shift register, one exact sequence period per loop. The AM sweep adds a 0.5 Hz tremolo quantised to the loop length, the warble steps through 1/3-octave bands with about 5 seconds per band, and the multitone sums 20 discrete tones with frequencies quantised to the loop. The burst program plays a 0.4 second noise burst every 4 seconds and is calibrated so the burst itself meets the level setting, so treat it as louder than the number suggests. Cascade duty-cycles sweep and noise with rest blocks and inverts polarity on alternating blocks, so the program has no net DC component across a full cycle. Level is calibrated in dBFS RMS with a hard cap that keeps peaks below -6 dBFS. The design rationale is in our white paper.
Can you actually hear the difference between two files? A and B are played as a randomised X. You say which one X is, and we compute the exact binomial probability of getting your score by guessing. Files are decoded locally in your browser; nothing is uploaded.
Each trial, X is randomly A or B with equal probability. After n trials with k correct identifications, the p-value is the exact two-sided binomial probability of scoring at least that far from chance if you were guessing. p below 0.05 counts as significant evidence of an audible difference; p below 0.01 is strong evidence. Anything else means no audible difference is proven at that trial count, which is itself a useful result. With your consent via the Finish button, an anonymised score (trials, correct, p-value, sample source; nothing else) is sent to our analytics so we can see how audible these differences are in the wild. The methodology is documented in the companion white paper.
One-tap generated signals for verifying wiring after a new cable install. Keep the volume low: the polarity pair and the woofer sweep are bass-heavy.
Three 880 Hz beeps from the left speaker only. If you hear them on the right, your channels are swapped.
Three 1320 Hz beeps from the right speaker only. The higher pitch also helps confirm which side is which.
An 880 Hz tone in both channels, in phase. It should image as a tight phantom centre, midway between the speakers, with equal loudness on each side.
100 Hz in both channels, in phase. Bass should sound full and solid, locked to the centre.
The same 100 Hz with the right channel inverted. With correct wiring this should sound thin, hollow and diffuse, with much less bass than the in-phase tone. If it sounds fuller, one speaker is wired backwards.
A slow 8-second sweep through the woofer band. Listen for rattles, buzzes or cabinet resonances that only appear at certain frequencies. Keep the level modest.
One-tap diagnostic signals for evaluating what your system does with a stereo image. Keep the volume modest; several of these are noise-based and sound louder than the meter suggests.
Pink noise switching between speakers every second. Each side should sound identical in tone and level, and the image should snap cleanly between speakers with no centre leakage.
Noise panning smoothly from hard left to hard right over 6 seconds. The image should glide in a straight line at constant loudness, with no jump in the middle or dip at the ends.
Noise bursts stepping through 25, 50, 75 and 100% left and right. Each step should land at a distinct, stable position; blurred or wandering positions suggest imaging or room problems.
Pink noise with the right channel inverted. Should sound extremely wide, diffuse and hard to locate, wrapping around the sides. A centred or narrow sound here suggests a channel or phase integrity problem.
Alternating 2-second blocks: identical noise in both channels (narrow, upfront) versus independent noise in each channel (wide, recessed). The contrast between the two is a rough gauge of how your system and room render front-to-back depth.
Honest caveat: there is no height channel here. These band-limited noise variants rely on spectral cues that many listeners perceive as vertical position. Treat it as an ear exercise, not a measurement.
Noise shaped to the low-mid band. Most listeners localise this low in the stage, near floor level.
Noise shaped to the presence band. Tends to localise at tweeter height, straight ahead.
Noise shaped to the brilliance band. Often perceived above the speakers; compare with the low band for the full effect.
Short transient bursts at 2, 4, 6 and 8 per second. Attacks should stay separate and crisp as the tempo rises; smearing or blurring points at slow drivers, room splash, or an over-damped amplifier.
One isolated 20 ms transient. Should be a single clean crack with immediate silence after it; any echo, buzz or tail is coming from the room or the speakers, not the signal.
Warbling tones stepping through 1/3-octave bands from 20 to 200 Hz, 2 seconds each. Every band should speak at a similar level; a band that booms or vanishes is your room, not the cable.
A slow 20-300 Hz sweep with 2-second dwells at 40, 80 and 160 Hz. Frequencies that suddenly swell, sustain or rattle the room are your standing-wave hotspots.
Band-limited noise sweeping 50-400 Hz. With a well-integrated subwoofer the level should stay even all the way up; a dip near the crossover point means the phase or crossover setting needs work.
A 1 kHz tone alternating between channels while the right side drops in 0.5 dB steps. Note the round where you first hear the image pull left; that is roughly your balance sensitivity.
A 1 kHz tone stepping down in 6 dB increments to -30 dB. The step where it disappears into room noise marks your system's usable dynamic floor at that listening level.
The engineering notes behind these tools, written up as short papers: