For music professionals, audio engineers, sound technicians, sound system installers and audio students.

Equally great both for quick reference and for long - term live spectra display. Supports multiple FFT sizes, adjustable averaging time and bandwidth, selectable mic input, selectable plot color.

Main features:
- vide range of frequency resolutions & averaging times
- scalable & movable plot that animates smoothly
- uses the whole audio range even on built-in mic
- selectable input source/mic or external device

With Spectrum-Eye, You can:

- monitor sound quality on concerts,
- ring out feedback in stage monitors,
- find resonances in acoustic environments,
- evaluate spectral properties of audio material in studio,
- develop Your hearing skills (frequency - aware hearing practice),
- detect problematic frequencies in speech/music,
- tune up car sound systems

Supports external microphones & audio interfaces compatible with Your iPad or iPhone. Currently uses sum of input channels 1 & 2.

Allows selecting preferred iPad mic when no external audio input is connected. You will discover how many mics and mic directivity configurations Your device has.

Uses iOS "Audio measurement mode" to bypass built-in mic processing. This setting too can be switched on/off for comparison.

Nominal sampling rate, Hz: 48000
Measurement frequency range, Hz: 8...22000
Measurement magnitude range, dB: 144dB
Magnitude precision, dB: ± 0.2
Frequency resolution (bandwidth):
- 1 octave
- 1/3
- 1/6
- 1/12
- 1/24
- 1/48
- 1/96 (iPad only)

App also employs pink noise generator for cases where You will use it with external audio interfaces. You can use the app as a pink noice generator even when screen is off.

Basic usage tips:

Re-position plot by sliding on scales (frequency scale for moving horizontally, dB scale for moving vertically). Scale the plot horizontally or vertically using two finger pinch.

Slide Your finger over the plot to move the cursor and see it's position in Hz and dB.

You can also find some tweaks and fine - tunings in Settings, accessible using three-dot button on top left.

The app is in active development, Your suggestions welcome!

What’s New

Version 1.3.3

- frequency range popup has all frequency labels
- better display of parameters in Settings -> Input source
- sample rate checks for more stable operation
- ready for new 11" & 12.9" iPads!
- more distinct scale labels

Ratings and Reviews

4.8 out of 5
6 Ratings

6 Ratings

Gio89kid ,

Great calibration app

This app allows you to send pink noise through the headphone jack and read the generated output with the integrated mic on the phone.

Very well designed and has many options and features. The only thing I would say it is lacking is an overall decibel meter to check loudness, but even if that never becomes a feature this is a great app and does what it is designed to do very well.

Developer Response ,

Thank You for Your kind review! We will keep working on the app so stay tuned, and thank You for a good suggestion.

The_Myth_Maker ,

Excellent app, one feature request

Great frame rate, pretty low latency, performs very well. However, I wish the resolution could get as fine as 1/100 or if I could type in an exact frequency to monitor instead of touching the frequency closest to the one I want, not getting the exact one I want because of the course resolution.

Developer Response ,

Thank You for a valuable feedback. Regarding max resolution: on iPad it’s 1/96 which is almost what You want. Unfortunately, higher resolutions are not practical as it will double the latency, require more computation.

Makc_Z ,

Favorite Spectrum so far

Very fast, light and easy to use! My favorite for now and ever!

Developer Response ,

Thank You for Your positive review!


Naumenko Oleg
27 MB

Requires iOS 9.3 or later. Compatible with iPhone, iPad, and iPod touch.


English, Ukrainian

Age Rating
Rated 4+
© 2018 Oleg Naumenko


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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