Spectrum Analyser

keuwlsoft

About this app

Audio spectrum analyser for your microphone.

64 up to 8192 frequency divisions (128 to 16384 FFT size).
22 kHz spectrum range (can reduce down to 1 kHz for higher resolution).
FFT Windowing (Bartlett, Blackman, Flat Top, Hanning, Hamming, Tukey, Welch, or none)
Auto-scale or pinch to zoom, drag to pan.
Linear or logarithmic scales.
Peak frequency detection (polynomial fit).
Averaging, Min and Max.
Save CSV data files (uses Write External Storage Permission).
Free or snap to peak cursor.
Octave Bands - Full, half, third, sixth, ninth or twelfth bands.
Weighting – A, C or None (A weighting filters the high and low frequencies according to how the ear perceives sound loudness).
Musical note indicator (green if within 5 cents, orange if within 10 cents).
Auto-scaling microphone input trace.
For best response on slower devices, keep the FFT size low.

More detailed explanation available on website

Ratings and reviews

Useful but the screen update interval is too slow. Others manage 30 frames per sec for a smooth graph. Its running 2 frames/sec no matter how far up/down I set various options. Buttons on the control panel too small to use, must have been programmed on a low res screen. Adjustable dB and Hz axis is useful as is C, Z and A dB weighing. But, it shows no response below about 50Hz even though my mic works far below that. It could be a nice app but it needs updating.

As far as a spectrum anilyzer goes it does alright but you can't adjust where the display line sits. Either nearly maxed at top or mostly unseen at the bottom unless you turn up the sound? Using it to set up speakers for flat output will require a source playing test tones since this has none built in. The auto leveling is hindering it's usefulness as a testing tool, you're limited in source volume output.

This is a useful and fun app! I can do basic stuff, to show others, or monitor a longer-term project. It enabled me to show a friend why his dog hated the new electronic nail-clipper (vibrations btw!), check speakers, and check a room's acoustics.

What's new

Version 1.42: Updated to use newer code libraries to target newer devices.
If you use the app to save data, the files will now be located in the documents folder, in a \keuwlsoft\spectrum_analyser sub directory.