Comparison

Transfer Function vs Open Sound Meter

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

Head to head
About

Transfer Function

This app performs dual-FFT acoustic analysis for sound systems, including music. It offers magnitude, phase, and coherence graphs, a delay finder, and a signal generator. It can operate with internal microphones or external audio interfaces for comprehensive sound system monitoring and equalization.

Highlights
  • Dual-FFT acoustic analysis
  • Magnitude, Phase, Coherence graphs
  • Delay Finder
  • Signal Generator
  • Music as signal source
  • Internal microphone support
  • Two-channel audio interface compatibility
Features
Read full description

Transfer Function is a dual-FFT acoustic analysis app that is used for sound system audio analysis. Since it can operate with music as the signal source, it can be used during a musical performance to monitor and turn the system equalization during the show. Transfer function includes: -- Magnitude Graph -- Phase Graph -- Coherence Plot -- Delay Finder -- Signal Generator Normally a transfer function requires a two-channel interface, and that is true with this one, also, if you want to use it with program material (music). However, you can use our Transfer Funciton with the internal iOS microphone, if you can send the pink noise generator output to the sound system input. In this configuration, the internal generator is routed back to the input as the reference channel. You can measure delay, magnitude, and phase using this setup. When you use Transfer Function with a two-channel audio interface to run, such as the Studio Six Digital iAudioInterface2, then you can also use any audio source as the test signal, including music. See our website for more information.

About

Open Sound Meter

This application allows real-time tuning and control of audio systems. It provides comprehensive measurement and analysis tools for various audio parameters, with options to store, adjust, and average results. Calibration files and direct console connections enhance measurement accuracy.

Highlights
  • Real-time audio system tuning
  • Spectrum, SPL, Magnitude, Phase analysis
  • Store, adjust, and average measurements
  • Apply calibration files for microphones
  • Direct connection to mixing consoles
  • Project saving to device or iCloud
Features
Read full description

Open Sound Meter is an application for tuning and controlling audio systems in real-time. Allows to measure and analyze: - Spectrum - SPL (RMS, Leq) - Magnitude - Phase - Group delay - Phase delay - Coherence - Impulse - Step - Spectrogram - Impedance - Nyquist plot - Crest factor You can store any result. Stored measurement can be adjusted by gain, delay and polarity, adjusted with filters, equalization. Math function gives you a possibility to average your measurements, virtually join them and predict how they will sound together. For better results, you can apply calibration files for your microphones. For the measurement, you can use any iOS compatible audio interface or connect to your mixing console. Save the project on the device or in iCloud. Direct connection works with Behringer X32, Midas M32, Allen&Heath Qu, DiGiCo S21/S31/SD12/UB-MADI, Yamaha TF and other consoles that have audio over USB. For Yamaha CL/QL you can use Dante AVIO adapter.

Screenshots

Transfer Function3 screens
Open Sound Meter1 screens

Verdict

The call

The clearest difference is review sentiment: Open Sound Meter at 100% against Transfer Function's 25%. Open Sound Meter also leads on rating (5.0 vs 3.0) and in-app purchases (none vs 1). Transfer Function's advantage is price ($49.99 vs $69.99). On ratings volume, ads, monetization model 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

Transfer Function costs $49.99 and Open Sound Meter $69.99 up front. Transfer Function sells 1 one-off in-app purchase. Open Sound Meter asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Open Sound Meter holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 5 respectively. Written reviews point the same way: 25% of Transfer Function's written reviews are positive against 100% of Open Sound Meter's.

UpkeepUpdate frequency

Transfer Function ships an update every 6 months, Open Sound Meter every 2 months. The most recent releases landed on September 24, 2026 and September 11, 2026 respectively.

Scorecard6 real differences · 4 level
Transfer Function versus Open Sound Meter: the parameters behind the verdict, then further details
ParameterTransfer FunctionOpen Sound Meter
Price$49.99 — better$69.99
Rating3.0 (2 ratings)5.0 (5 ratings) — better
Positive reviews25.0% of reviews100.0% of reviews — better
Number of ratings25 — better
Update frequencyEvery 6 monthsEvery 2 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.012.0 — better
Further details — not scored
Size33 MB45 MB
Age rating4++4
DeveloperAndrew SmithPavel Smokotnin

Customer experience

Transfer Function

All ratings2 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews4 reviews
Positive25.0%
Neutral0.0%
Negative75.0%

Open Sound Meter

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

Transfer Function

One-time1
  • Reference Curves Option$14.99
None

Open Sound Meter

No in-app purchases

Questions

Is Transfer Function free?
Transfer Function costs $49.99, and also offers in-app purchases.
Is Open Sound Meter free?
Open Sound Meter costs $69.99, with no in-app purchases.
Which has better reviews, Transfer Function or Open Sound Meter?
Open Sound Meter is rated higher. Transfer Function averages 3.0 out of 5 from 2 ratings, while Open Sound Meter averages 5.0 from 5 ratings.
Do Transfer Function or Open Sound Meter have ads?
Neither Transfer Function nor Open Sound Meter shows ads.
Which is updated more often, Transfer Function or Open Sound Meter?
Transfer Function ships an update every 6 months, and Open Sound Meter every 2 months. Most recently, Transfer Function was updated on September 24, 2026 and Open Sound Meter on September 11, 2026.

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