Stimulus

About

Stimulus is a test signal rack for live sound engineers. Four generators, a proper master section, and measurement signals that behave the way your analyzer expects. On iPhone it is a single generator with the same master section, meters, timer and export, for a signal from your pocket. GENERATORS - Tone: sine from 10 Hz to 22 kHz with a log slider, typed entry, and keyboard nudge (1 percent steps, 10 percent with Shift). - Sweep: log or linear, any range in either direction, continuous or stepped in 1/3-octave dwells, one-shot or looped, with return. Hold freezes the sweep at its current frequency and lets you scrub the held tone. - Harmonics: a fundamental with seven partials (f/4 to 5f) on faders, for exercising a system with controlled harmonic content. - Noise: pink, red/brown, or white, continuous or in bursts, full range or band-limited to 1 octave or 1/3 octave around a centre frequency. - Identify: GLITS (Graham's Line Identification Tone System) and the EBU Stereo ID for stereo left/right checks, positive-going polarity pops in sub, full-range, and HF widths, and a sharp click for aligning mains and delays by ear. - Measure: pseudorandom pink noise period-matched to your analyzer's FFT frame (32K, 64K, or 128K), and a cycle-synchronised log sweep. Both loop seamlessly; export writes exactly one frame for analyzer playback. RACK AND MASTER - Up to four generators at once, each with level, left/right/both routing, polarity invert, mute, exclusive solo, and click-free fade in and out. - Master level with a hard limiter at -3 dBFS, a 20 dB dim for talking over the system, master fade in and out in seconds, and an auto-stop timer. - Stereo peak meters that follow every fade. EXPORT - Render any generator or the whole mix to WAV or AIFF at 44.1, 48, or 96 kHz for playback machines and test systems. SAFETY - New generators always start at -18 dBFS. Nothing in the app defaults loud. One purchase covers Mac, iPad and iPhone.