AcousticCheck offers two ways to excite the room: a clap-style impulse and a sine sweep played through an external speaker. Both end in the same Schroeder analysis; they differ in how the sound energy gets into the room.
Impulse: fast and gearless
Clap your hands, pop a balloon, or slam a book shut. The app records the room’s response and integrates the decay.
Use it when you want a quick sanity check, you have no gear with you, and the room is quiet and small-to-medium sized. An indoor impulse measurement completes in about eight seconds.
Limits: a hand clap carries little energy below ~250 Hz, so the low bands come out noisier. In rooms with audible HVAC the signal-to-noise ratio may not be enough for a clean fit — watch the per-band R² values.
Sweep: more energy, more control
The app plays an exponential sine sweep through a Bluetooth speaker and deconvolves the response into an impulse response. Because the energy is spread over time and frequency, the effective SNR is far higher.
Use it when you need reliable low-frequency bands, the room is large, or the ambient noise is not under your control. This is the method we recommend for anything you’ll put in front of a client.
Rule of thumb — impulse for the first look, sweep for the number you report. If the two disagree noticeably in the low bands, trust the sweep.
Choosing in the app
The method selector sits on the measurement setup screen. Sweep requires a connected speaker (the app checks); impulse is always available. Both methods are included in Plus; the Free tier includes impulse only.