Polar Pattern Plotter is an iOS app for measuring sound directivy patterns for loudspeakers and microphones. The iOS binary is available for free download on the App Store:
Source code is provided here for those who'd like to help improve the functionality of the app for the good of the community. See below for suggested improvements!
Paper: "Visualizing Sound Directivity via Smartphone Sensors," by S.H. Hawley and R.E. McClain Jr., The Physics Teacher 56, 72 (2018). Also pre-print on arXiv.org.
- Make sure you have Xcode installed.
- Clone this GitHub repository.
- Open the .xcworkspace file with Xcode, e.g.
$ open PolarPatternPlotter.xcworkspace - Choose "Run" from the "Build" dropdown, or just click the "Play" (
▶️ ) button.
- A variable frequency-filter, to reject background noise and to allow simultaneous experiments (at different frequencies).
- Corrections to angular drift. Currently there's a slider but it's not enabled. The code for this isn't quite working and it's commented-out in the source.
- Interpolate / smooth the data, and do polar-harmonic decomposition
- Port it to Android
- Some kind of "burst mode," where the phone outputs the test signal and rejects sounds that arrive after some (tunable) interval, to allow for use in reflective rooms.
Author: Scott Hawley