Transfer Function vs D
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Dual-FFT acoustic analysis
- Magnitude, Phase, Coherence graphs
- Delay Finder
- Signal Generator
- Music as signal source
- Internal microphone support
- Two-channel audio interface compatibility
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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.
D
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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
Verdict
The clearest difference is price: D at Free against Transfer Function's $49.99. D also leads on in-app purchases (none vs 1) and update cadence (every 2 months vs every 6 months). Transfer Function's advantage is iOS requirement (15.0 vs 17.0). On 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
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.
Transfer Function ships an update every 6 months, D every 2 months. The most recent releases landed on September 24, 2026 and September 8, 2026 respectively.
| Parameter | Transfer Function | D |
|---|---|---|
| Price | $49.99 | Free — better |
| Rating | 3.0 (2 ratings) — better | — |
| Positive reviews | 25.0% of reviews | — |
| Number of ratings | 2 — better | — |
| Update frequency | Every 6 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 33 MB | 33 MB |
| Age rating | 4+ | 4+ |
| Developer | Andrew Smith | Yamaha Corporation |
In-app purchases
Transfer Function
- Reference Curves Option$14.99
D
No in-app purchases









