CLL Audio Tools

About

CLL Audio Tools puts the everyday measurement and practice tools of a studio or live-sound kit on your iPhone. Everything runs on the device: no account, no ads, no tracking, and audio is never recorded or uploaded. MEASURE • SPL Meter — A- and C-weighted sound level estimates with Fast and Slow response. Add an optional reference calibration against a trusted meter to track session LAeq, LASmax and a NIOSH-rule dose estimate. • Spectrum Analyzer — live FFT spectrum and 1/3-octave RTA in landscape, with held peaks, snapshots, and import of a microphone response file (.txt or .frd) for display correction. • Tuner — note, cents and frequency with an A4 = 440 Hz reference. PLAY • Signal Generator — sine, white noise, pink noise, sawtooth and sweep from 20 Hz to 20 kHz, with output level in dBFS. • Metronome — 20–300 BPM, tap tempo and four subdivisions. Keeps playing when you switch apps or lock the screen. CALCULATE • Distance Delay — speaker-to-listener distance in meters or feet to milliseconds. • Delay — note values in milliseconds from BPM. • Frequency — Hz to note and cents, and back. • dB — dBFS, dBu and dBV with a selectable reference level. • Wavelength — wavelength and frequency at a chosen air temperature. A note on accuracy: iPhone microphones are not certified measurement microphones. SPL readings are estimates and are not a substitute for a Class 1 or Class 2 sound level meter or for professional hearing-protection advice. Made by Critical Listening Lab, ear training for musicians and audio engineers: criticallisteninglab.com