Comparison

Transfer Function vs D

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

D

Control DXR/DXS mk3 speaker parameters remotely via Bluetooth from your iOS device. Adjust levels, EQ, and more in real-time from anywhere in the venue. Monitor speaker status and manage multiple units simultaneously.

Highlights
  • Remote parameter control via Bluetooth
  • Real-time level and EQ adjustments
  • Monitor limiter activity and temperature
  • Control up to ten speakers simultaneously
  • Grouping for unified control
  • Scene save/recall functionality
Read full description

D‑Remote is a dedicated software application that allows you to remotely control DXR/DXS mk3 parameters using your iOS device via Bluetooth. With D‑Remote, you can make adjustments from wherever you are—on stage, at FOH, or while listening from the audience area—so it’s easy to balance levels and refine sound quality in real time. It supports control of all parameters, including level, delay, EQ, crossover, FBS, ducker, identification, panel lock, and scene save/recall. In addition, D-Remote monitors each speaker’s limiter activity and temperature, and displays error alerts. The app can control up to ten DXR/DXS mk3 speakers simultaneously, and grouping is available for unified level and mute control—helping streamline setup and operation.

Screenshots

Transfer Function3 screens
D4 screens

Verdict

The call

The clearest difference is price: D at Free against Transfer Function's $49.99. D also leads on rating (5.0 vs 3.0) and in-app purchases (none vs 1). Transfer Function's advantage is iOS requirement (15.0 vs 17.0). On ratings volume, 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

D is free to download; Transfer Function costs $49.99 up front. Transfer Function sells 1 one-off in-app purchase. D asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

D holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 3 respectively.

UpkeepUpdate frequency

Transfer Function ships an update every 6 months, D every 3 months. The most recent releases landed on October 24, 2026 and October 22, 2026 respectively.

Scorecard5 real differences · 5 level
Transfer Function versus D: the parameters behind the verdict, then further details
ParameterTransfer FunctionD
Price$49.99Free — better
Rating3.0 (2 ratings)5.0 (3 ratings) — better
Positive reviews25.0% of reviews—
Number of ratings23 — better
Update frequencyEvery 6 monthsEvery 3 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size34 MB34 MB
Age rating4++4
DeveloperAndrew SmithYamaha Corporation

Customer experience

Transfer Function

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

D

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

Transfer Function

One-time1
  • Reference Curves Option$14.99
None

D

No in-app purchases

Questions

Is Transfer Function free?
Transfer Function costs $49.99, and also offers in-app purchases.
Is D free?
D is free to download, with no in-app purchases.
Which has better reviews, Transfer Function or D?
D is rated higher. Transfer Function averages 3.0 out of 5 from 2 ratings, while D averages 5.0 from 3 ratings.
Do Transfer Function or D have ads?
Neither Transfer Function nor D shows ads.
Which is updated more often, Transfer Function or D?
Transfer Function ships an update every 6 months, and D every 3 months. Most recently, Transfer Function was updated on October 24, 2026 and D on October 22, 2026.

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