Mr. Spectrum

Mr. Spectrum - Audio Spectrum Analyser

This Application analyses audio data captured from the microphone and shows live updates of either the temporal waveform (scope mode) or the frequency spectrum (fft mode) on the display.
An app for everyone who wants to explore the sound that surrounds him.
Use it to:
*) find out at which frequency there is a feedback when rehearsing or playing a concert with the band
*) find out how high you can whistle
*) ...



Features:
*) uses full screen size for graph display
*) independently zoom and drag display graph in x and y direction (use one finger only)
*) labeled x and y scales with auto-adapting tick marks when dragging or zooming
*) portrait or landscape display orientation
*) run/pause button for analysing the data in detail
*) toggle between scope and fft mode while running or paused
*) peak indicator, highlighting the most prominent peak in the spectrum
*) frequency readout display (in Hz) of the most prominent peak in the spectrum
*) overall average amplitude readout display (in dB)
*) quick set of display region: set x display to full dataset, set y display to default, set y display to fit current data
*) sample length: 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536
*) sampling frequency: 8k, 11.025k, 22.01k, 44.1k, 48k
*) update display multiple times while aquiring sample length (1, 2, 4, 8, 12, 16, 20, 30, 40)
*) 4 different fft modes: normal, average, integrating, averaged integrating
*) fft linear or log vertical scaling
*) highly responsive to user interactions (drag/zoom)
*) all user settings are stored when closing app, to have same settings for next start

The 4 fft aquisition modes:
- normal: simply show currently calculated fft on screen
- average: only add a certain amount of the current fft to the displayed fft, to achieve a smoothing in time. The amount can be user controlled.
- integrating: the currently calculated fft is added to the displayed one, so that the values are steadily increasing. This mode provides a reset button.
- averaged integrating: this mode also sums up all incoming spectra, but the data are resized so that the values are not increasing. This mode provides a reset button.