Spectrum Analyzer App

with 12 Comments

Spectrum analyze screen cap

Spectrum Analyze is Red Pine Labs’ audio-analyzing app, and perhaps the best available on the Android market. With more than 50,000 downloads and a rating of 4.3 out of 5 stars, the app can be downloaded for free in the Google Play Store. Special features are available on an upgrade for just $1 USD.

Free features include a pause, peak reset, the ability to save a screenshot with a single button, and a share button.

For the extra $1 USD, the user can set high and low limits for the X and Y axis, the number of seconds per frame, and size of FFT.

Get it here:




Google needed a Privacy Policy.  It can be found here: https://redpinelabs.com/about-red-pine-labs/spectrum-analyze-privacy-policy/


12 Responses

  1. Karoly Kortelyesi
    | Reply

    Hi Sir,
    What does the 0dB refer to?
    Thank you!
    Karoly Kortelyesi

    • Bryce Johnson
      | Reply

      The dB in the app is a relative measurement. 0 dB would be theoretically when the the microphone input ADC is completely saturated.


  2. Michael Lee
    | Reply

    Good day,
    I recently downloaded your app, and found it very satisfactory. So I wanted to support it further and bought the special features.
    Anyways, I have a question about the units of measurement used in the app. I understand that decibels represent a value relative to a reference value on a logarithmic scale. But what is the reference value used in the measure? And why is the Y scale initially set between 0dB ~ -120dB? Pardon me if my questions sound naive, I have limited knowledge on the subject. Thank you in advance for answering to my question.

    • Bryce Johnson
      | Reply

      Hi Michael,
      0 dB would be theoretically when the the microphone input ADC is completely saturated. There isn’t a reference value besides that because that would need the microphones on every android device to be calibrated. So you would need to make your own reference. If you measure a pitch with a known dB(SPL) then you could reference off of that. Or you can tell the difference between two pitches currently being heard.

  3. Matthias Wandel
    | Reply

    Love the app. I am just working on a video showing how to use a spectrum analyzer app to measure the RPM and cutter speed of machines. This was the best app for the job, and nearly free (I did buy the $1 upgrade)

    • Bryce Johnson
      | Reply

      Glad to see you are getting some use out of it! Love your videos by the way. Just was showing my Dad the pantorouter videos over Christmas. Also had a friend notice you using the app on your metal plate resonance video!

  4. OT
    | Reply

    Hello, I downloaded your app and experimented with using it but I’m not sure how to interpret the results. I used the microphone built into my LGV20 to record some test tones on a test record played on a turntable. Are the red and green line graphs meant to denote the left and right channels or something else? Also is it possible to shift the scale so that the baseline is at 0db? Thanks.

    • Bryce Johnson
      | Reply

      Hi OT,
      The green is the live value and the red is the peak value since the last refresh. There currently is not a way to shift the signal to have the baseline at 0db.


  5. james pruett
    | Reply

    is the DFT source code available?

    I want to build an app (for me, not for sale) which my horn when it hears any car horn… ‘Creating a horn-a-geddon

    I just need the guts in java. I have tons of other apps…. “See cellurl on play store”.

    -Jim Pruett

  6. Sergiy
    | Reply

    Thanks for nice Analyzer. It helps in EQ tuning.
    Could you please add Notes right under the Freq scale?
    There’re few scale standards: 440 and 442 are more usable.
    (Please see http://pages.mtu.edu/~suits/notefreqs.html)
    It would help even in precious piano tuning.

  7. Chris S
    | Reply

    Hi there,
    Lovely app !
    Is there any technique that would allow me to compensate for my phone microphone’s frequency response ?
    I’m no expert, but if the app had an option to feed a delta function, from the phone’s speaker perhaps, in a calibrate mode on the app, would that achieve the desired calibration ?
    Either way, thanks so much for a great app !

  8. Dan
    | Reply

    Hi Bryce,
    I like your Spectrum Analyzer app, and I’ve used it from long time when I have to work with sound frequencies.
    Now I have a Samsung A54 with Android 14 and One UI 6.0 kernel 5.15.104. The app stopped working and the Google appstore says This app isn’t compatible with your device anymore.
    I would like to ask if you plan to update the app?
    Best wishes:

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