Comparison

RTA Pro vs Audio Function Generator

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

RTA Pro

Transform your iOS device into a professional audio analysis tool. Analyze ambient noise frequencies, pinpoint room resonance, and set up sound systems for events. Features include custom calibration, multiple display modes, and adjustable speed settings.

Highlights
  • Real-time audio spectrum analysis
  • Frequency range 32Hz to 16kHz
  • Linear, dB(A), and dB(C) weightings
  • 1/3 Octave Bands, Octave Bands, and FFT display
  • Adjustable speed settings
  • Custom calibration options
Currently charting
Read full description

RTA Pro is a real time audio spektrum analyzer. It turns your iOS device into a powerful audio test system usually seen only in audio research laboratories and music studios. Such instruments are used to analyze the frequency spectrum of ambient noise, e.g. to be able to pinpoint frequencies which cause rumble in a room. Another use is the level setting setting of PA systems for concerts. Features: RTA Pro requires iOS11 or later and has been calibrated for the microphones of most iPhones. Custom calibration is also possible. The frequency range is 32Hz to 16kHz. Linear display, as well as weightings for measuring dB(A) and dB(C) is provided. Apart from 1/3 Octave Bands and Octave Bands, RTA Pro also features the display of a Fast Fourier Transform (FFT). The speed is adjustable to impulse, 128ms and 1 second.

About

Audio Function Generator

Generate various audio test tones, including sine, square, triangle, and sawtooth waves. Explore frequency and volume sweeps, noise generation, and custom preset creation. Advanced features like extended frequency ranges and multi-tone playback are available with an upgrade.

Highlights
  • Generate sine, square, triangle, and sawtooth tones
  • Frequency and volume sweep generation
  • Noise generation (white, pink, violet, etc.)
  • Custom preset creation and saving
  • Extended frequency range (PRO feature)
  • Multi-tone playback (PRO feature)
Features
Read full description

This is the highly recommended and praised Function Generator App - an amazingly great and powerful tone generator. Enriched with a vast amount of features yet it is extremely intuitive and designed for simplicity. Get to know this great App now! It is very well maintained and has received considerable upgrades over the past years. So, … what can you do with this App? • PLAY TEST TONES Sine, Rectangular, Triangular and Sawtooth. • PLAY FREQUENCY SWEEP TEST TONES in both directions (minimum to maximum frequency and maximum to minimum frequency). • PLAY VOLUME SWEEPS (from minimum to maximum volume). • Try the SWEEP REPEAT / WOBBLE function. • Try the MUSIC TONES PLAYBACK. • Experiment with the huge FINE TUNE SELECTON, PRESETS SELECTION! • Or create your own CUSTOM PRESETS! • And SAVE an endless amount of CONFIGURATIONS (Frequency, Sweep, Noise) for later quick access and direct playback function. • Even play back different kinds of NOISE – White, Pink, Violet, Grey, Brown, Blue is also supported. The Function Generator is AMAZINGLY INTUITIVE and SIMPLE to use! AND THESE ARE THE ADVANCED SETTINGS/FEATURES (upgrade to PRO required): => Extending The Frequency Range (1Hz - 21kHz) => Extending The Sweep Times (0.1s - 600s) => Changing Min/Max Slider Frequency Ranges => Changing Max Sweep Time Slider Range => Changing Signal Amplitude => Enabling Of The Sweep Repeat / Wobble Function => Frequency Slider Setting to Linear or Logarithmic => Left/Right Channel Individual Selection => Permanently Saving Custom Presets => Saving Of Endless Number Of Audio Configurations => Phase Out Setting (custom phase shift of the generated signal) => BPM (Beats per Minute) Feature => Dual Function Generator => MultiTone Generator (playback of up to eight individual tones) => Background Theme Selection (Light/Dark) Check out the tutorial page: www.ee-toolkit.com/audio-function-generator

Screenshots

RTA Pro4 screens
Audio Function Generator4 screens

Verdict

The call

The clearest difference is price: Audio Function Generator at Free against RTA Pro's $5.99. Audio Function Generator also leads on review sentiment (77% vs 50%) and ratings volume (2.2K vs 2). RTA Pro's advantage is in-app purchases (none vs 1) and chart position (#191 vs unranked). On update cadence, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Audio Function Generator is free to download; RTA Pro costs $5.99 up front. Audio Function Generator sells 1 one-off in-app purchase. RTA Pro asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Audio Function Generator holds the better App Store score, 4.7 against 4.5. That said, the two scores are not equally well evidenced: Audio Function Generator has 2.2K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 50% of RTA Pro's written reviews are positive against 77% of Audio Function Generator's.

UpkeepUpdate frequency

RTA Pro ships an update every 3 months, Audio Function Generator every 6 weeks. The most recent releases landed on October 8, 2026 and October 13, 2026 respectively.

Scorecard8 real differences · 3 level
RTA Pro versus Audio Function Generator: the parameters behind the verdict, then further details
ParameterRTA ProAudio Function Generator
Price$5.99Free — better
Rating4.5 (2 ratings)4.7 (2.2K ratings) — better
Positive reviews50.0% of reviews77.1% of reviews — better
Number of ratings22.2K — better
Update frequencyEvery 3 monthsEvery 6 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
Best chart rank#191 — better—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.615.5 — better
Further details — not scored
Size12 MB14 MB
Age rating4+4+
DeveloperMatthias SchorerThomas Gruber

Customer experience

RTA Pro

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

Audio Function Generator

All ratings2,191 ratings
Positive91.8%
Neutral3.1%
Negative5.1%
Written reviews271 reviews
Positive77.1%
Neutral6.3%
Negative16.6%

Bugs and requests

RTA Pro

Not enough reviews yet to summarise bugs or requests.

Audio Function Generator

Reported bugs

4 issues
  • Crashes on launch
  • Volume slider issues
  • Airplay not working
  • Sound distortion when display is active

Requested features

6 requests
  • Add download/save feature for custom sounds
  • Improve sweep function (continuous mode, better frequency control)
  • Add more multi-frequency rows
  • Implement 432Hz base frequency option
  • Add phase control for noise generators
Show 1 more
  • Improve accessibility (VoiceOver support)

In-app purchases

None

RTA Pro

No in-app purchases

1 purchases

Audio Function Generator

One-time1
  • Upgrade to PRO$9.99

Questions

Is RTA Pro free?
RTA Pro costs $5.99, with no in-app purchases.
Is Audio Function Generator free?
Audio Function Generator is free to download, with in-app purchases available.
Which has better reviews, RTA Pro or Audio Function Generator?
Audio Function Generator is rated higher. RTA Pro averages 4.5 out of 5 from 2 ratings, while Audio Function Generator averages 4.7 from 2.2K ratings.
Do RTA Pro or Audio Function Generator have ads?
Neither RTA Pro nor Audio Function Generator shows ads.
Which is updated more often, RTA Pro or Audio Function Generator?
RTA Pro ships an update every 3 months, and Audio Function Generator every 6 weeks. Most recently, RTA Pro was updated on October 8, 2026 and Audio Function Generator on October 13, 2026.

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