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

Very cool! I have a degree in geophysics, and FFTs are a primary method to analyze seismic data. In the 80s it took a computer the size of a small RV to process the data... now you can do it on your phone. In real time. With a color display. (Just wish I still remembered what all the settings do...lol) Great app!

First app I felt I NEEDED to give a good review. Definitely the best quick analyzer that feels accurate enough for my use. I run front of house for bands in many different venues, this app makes it so easy to quickly see a frequency that may be problematic. Also has test tones and it's super fast and responsive. I have tried many MANY similar apps, both android and ios, and this one is by FAR the best for quick use.

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

What's new

◆ Improve usability on high-density displays