Spectroid

Carl Reinke

About this app

Spectroid is a real-time audio spectrum analyzer with reasonable frequency resolution across the the entire frequency spectrum.

💬 FAQ 💬

Q: Why are the dB values negative?
A: Spectroid uses dBFS (Full Scale) where 0 dB is the maximum power that the microphone can measure, so the decibel values are negative because the measured power is less than the maximum power.

Q: Can I zoom in on the spectrum plot?
A: Yes, do a two-finger pinch-to-zoom gesture.

Q: Why are there discontinuities/gaps in the spectrum plot and waterfall?
A: Spectroid uses multiple FFTs overlapped in frequency in order to provide better frequency resolution at lower frequencies than a single FFT. The caveat of this method is varied impulse response and minor discontinuities in frequency. The upside is that it can efficiently produce a spectrum that better matches the frequency resolution of human audio perception. It's still probably not as good as your ears though!

Q: Can I export the spectrum data?
A: Spectroid doesn't make your device a calibrated instrument. If you need the spectrum data then you should be using an actual spectrum analyzer rather than an app on your mobile device.

Ratings and reviews

Excellent app! Could use some features that are missing from web interface, but nothing one can't live without. I wish I could buy one and use it on several devices, but it seems you have to purchase separately for each device... maybe have a pro version? Fortunately, the ads aren't intrusive, so they can be easily ignored.

Frankly, this app helps restore my faith in humanity. Simple. Clean. Elegant, useful. No ads, no popups. I know the author points out he can't calibrate but just for fun, pull up an online tone generator on an adjacent computer and try comparing the results. I'm using this to debug some objectionable noise from some industrial fans. What a nice find. Thanks. Like a few others, I'd love the ability to record an audio clip along with the spectrum analysis. Not a big deal though. Bravo

Looks awesome with certain types of music. Any music with a piano or harmonic type instrument shows up clearly when you use it. Kicks, snares, claps, and hi hats as well, if you know what to look for. Very useful in eyeballing certain melodies of songs if you can't pick which notes are played in your head. Useful and fun. Also note: the quality of the visualization is directly proportional to the microphone quality, distance from sound, and the volume of sound.

What's new

◆ Improve usability on high-density displays