AUM vs SynthMaster 2
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
AUM
This app is a versatile audio mixer, recorder, and connection hub for mobile devices. It allows users to connect various audio sources, route signals, apply effects, and record mixes with high fidelity. It supports advanced features like MIDI control, synchronization, and integration with other audio apps and hardware.
- Connect hardware inputs/outputs
- Route audio and MIDI
- Host Audio Unit extensions
- Record mixes and individual tracks
- Synchronize with Ableton Link
- Built-in processing nodes
- MIDI control and routing
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AUM is the flexible audio mixer, recorder, and connection hub for your iPad, iPhone and iPod touch. Connect hardware inputs and outputs, Audio Unit extensions, Inter-App Audio apps, Audiobus, soundfile players, built-in signal processing and filters, in any configuration you want. Route anything to anywhere with mix-busses, effect sends, audiobus ports, and external multi-channel audio interfaces. Play hosted synths and instruments using the built-in keyboard or external MIDI controllers, or sequence them with AU MIDI plugins or from other apps using Virtual MIDI. Record mixes, individual tracks, or both, straight into the storage space of AudioShare (no copying of files needed), with synchronized start and end for perfect loops. Play back recordings, soundfiles and loops as channel sources in the mixer for backing tracks, further processing or mixing. Soundfiles can be opened from anywhere, including USB drives on iOS 13 and later. Route and filter MIDI in any way you like using the MIDI matrix. Combine and filter MIDI endpoints using MIDI buses. Synchronize everything with the transport clock and play in time with other apps or devices using Ableton Link. Connect external music machines and synchronize them with MIDI Clock. Includes built-in processing nodes for various stereo processing, Mid/Side balance and conversion, EQs and filters, limiting, clipping and saturation. Or use any 3rd party Audio Unit extension or Inter-App Audio effect. All controls in the mixer can be controlled via MIDI, including parameters of hosted and built-in plugins. "A brilliant idea that has been brilliantly executed. Top-notch technical stuff and highly recommended" - MusicAppBlog "Feature rich, powerful, intuitive, and simple to use" - DubSpot "Executes live mixing with surprising ease, with a load of extensive features under the hood, quick snappy response on the screen and audio" - AudioNewsRoom FEATURES • High quality audio up to 32-bit 192kHz • Clean and intuitive user interface with crisp vector graphics • Unlimited number of channels • Unlimited number of effect slots • Inserts and sends are configurable pre/post-fader • Internal busses for mixing, effect sends, signal splitting • Supports multi-channel audio interfaces for both inputs and outputs • Supports built-in speaker and mic, including stereo mic on devices that has it. • Supports Audio Unit extensions, Inter-App Audio and Audiobus • Route MIDI output from Audio Unit extensions • Supports Audio Unit multiple output and input busses (for side-chaining etc) • Highly accurate transport clock • Metronome with selectable output and optional pre-roll • Sends host sync to Audio Unit plugins and IAA apps • Play in time with Ableton Link, with Start/Stop support • Slave external hardware via MIDI Clock • FilePlayer with sync and looping with access to all your soundfiles • Records straight into AudioShare storage space • Record synchronized beat-perfect loops • Built-in nodes for stereo processing, filtering and dynamics • Latency compensation makes everything align at the outputs • Optional manual compensation using TimeOffset • Multiple Inter-App Audio / Audiobus output ports • Audiobus state saving • Built-in MIDI keyboard • Fully MIDI controllable • MIDI Matrix for routing MIDI anywhere • MIDI filtering for any MIDI destination • Combine MIDI sources or destinations using MIDI buses BUILT-IN SIGNAL PROCESSING • Stereo balance • Stereo to mono • Stereo panning • Mid/Side balance • Mid/Side - Stereo convert • Invert Phase • Parametric EQ • Low-shelf filter • High-shelf filter • Low-pass resonant filter • High-pass resonant filter • LP/HP combo filter • First order All-pass filter • Second order All-pass filter • Gain • Hard clip • Saturation • Lookahead peak limiter • System-provided Apple Audio Units
SynthMaster 2
This powerful software synthesizer offers a vast array of sound design capabilities, including multiple oscillator modes, extensive modulation options, and a wide selection of filters. Explore over 1000 factory presets or create your own unique sounds. Available as a standalone app or AUv3 plugin.
- Multiple oscillator modes (Basic, Additive, Wavetable, Vector)
- Extensive modulation architecture
- 6 filter categories
- Import custom wave files
- 1000+ factory presets
- Standalone app and AUv3 plugin
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KV331 Audio is proud to announce the availability of their award winning software synthesizer SynthMaster 2.9 on iOS platform. As being the first app developed using KV331 Audio’s new cross-platform UI framework, SynthMaster 2 runs as a standalone app or AUv3 plugin on iPads with iOS 11 and above. SynthMaster 2 supports native resolutions of various iPad devices. User interfaces are provided for 9.7, 11 and 12.9 inch iPads in 4 different skins (Blue, White, Dark, Proto). Separate interfaces are provided for the AudioUnit plugin as well. SynthMaster 2 comes with 1000 factory presets designed by world class sound designers such as BigTone, Nori Ubukata, NatLife and Yuli Yolo. Thanks to the comprehensive preset browsing features, users can easily filter presets by author name, bank name, instrument type or preset name and find the sounds that they are looking for. There’s also an IAP Shop, which lets users purchase additional sounds: 1. "Desktop Presets Upgrade": This IAP adds all factory presets in SynthMaster 2.9, increasing the total preset count to 2000. 2. "All Expansions Bundle": This IAP adds all current 38 SynthMaster preset expansion banks. Sound Engine: At the heart of SynthMaster 2’s powerful sound engine lies its oscillators, modulators, and filters. Oscillators: The oscillators can operate in 4 different modes to generate sound: 1. In Basic mode, the oscillator plays single cycle waveforms or samples. With the Oscillator Unison turned on, up to 8 voices per oscillator can be played. 2. In Additive mode, 8 Basic oscillators can be stacked up to create richer tones. 3. In Wavetable mode, the oscillator can play wavetables with up to 256 frames. 4. In Vector mode, 4 Basic oscillators are mixed in 2 dimensions. Modulators: Modulators are simply basic oscillators that can be added to other oscillators or modulate other oscillators’ or modulators’ phases. By connecting modulators to other oscillators or modulators, complex FM tones can be synthesized. Importing Wave Files into SynthMaster: While designing sounds, users can easily import wave files into SynthMaster 2. SynthMaster 2 can categorize those files into waveforms, wavetables or multi samples and import them accordingly. Filters: Once the sound is generated by the oscillators it goes through SynthMaster’s filters, which can operate in 6 different categories: Digital, VAnalog, Ladder, Diode Ladder, State Variable and Bite. Custom distortion can be applied before or after the filters as well. Modulation Architecture: SynthMaster 2 features a comprehensive modulation architecture with a wide range of modulation sources: 1. MIDI controls 2. Macros controls 3. 4 ADSR envelopes per layer 4. 4 Multisegmented envelopes per payer 5. 4 LFOs per layer 6. 4 Sequencers per layer 7. 4 Keyscalers per layer There’s real-time visual feedback that lets users see how modulation sources and targets are changing when a note is being played. This is extremely helpful when designing sounds with SynthMaster 2. New modulations can be created easily by dragging and dropping a modulation source onto a knob or slider control. Users can easily see which controls are modulated by a modulation source by clicking on that source. Controls that are being modulated by that source will display modulation amounts. By long pressing a control, the modulation amount can be edited without the need to go through the mod matrix. Arp/Sequencer: SynthMaster features a comprehensive arpeggiator / sequencer with 32 steps. Users can easily create sequences by recording steps one by one. Effects: Each of the 2 layers in SynthMaster has 5 insert effect slots. 13 different types of effects can be instantiated in any of those slots. There are also 2 global effect send busses which can be used to create more complex effect routings.
Screenshots
Verdict
The clearest difference is price: SynthMaster 2 at $14.99 against AUM's $24.99. SynthMaster 2 also leads on update cadence (every 3 weeks vs every 3 months). AUM's advantage is ads (none vs shown) and review sentiment (82% vs 68%). On rating, ratings volume, in-app purchases and monetization model 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
AUM costs $24.99 and SynthMaster 2 $14.99 up front. AUM sells 4 one-off in-app purchases and SynthMaster 2 sells 32 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.7 for AUM against 4.8 for SynthMaster 2. Both are backed by a comparable volume of ratings — 524 and 451 respectively. Written reviews are what separate them: 82% of AUM's written reviews are positive against 68% of SynthMaster 2's.
AUM ships an update every 3 months, SynthMaster 2 every 3 weeks. The most recent releases landed on September 22, 2026 and September 23, 2026 respectively.
| Parameter | AUM | SynthMaster 2 |
|---|---|---|
| Price | $24.99 | $14.99 — better |
| Rating | 4.7 (524 ratings) | 4.8 (451 ratings) — better |
| Positive reviews | 82.1% of reviews — better | 68.5% of reviews |
| Number of ratings | 524 — better | 451 |
| Update frequency | Every 3 months | Every 3 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Best chart rank | #91 — better | — |
| Devices | iPhone, iPad, iPod — better | iPad |
| Requires iOS | 12.0 — better | 15 |
| Further details — not scored | ||
| Size | 13 MB | 918 MB |
| Age rating | 4+ | 4+ |
| Developer | Kymatica AB | KV331 Audio |
Customer experience
AUM
SynthMaster 2
User reviews
AUM
From 524 App Store ratingsWhat we love
- 👍 Excellent audio routing and mixing capabilities
- 🚀 Powerful and flexible workflow
- 💡 Seamless integration with AUv3 and IAA apps
- 👍 Intuitive and clean user interface
- 👍 Reliable and stable performance
Room to improve
- 🐛 Occasional crashes or stability issues
- 💡 Lack of MIDI clock sync receive functionality
- 💡 Limited visual customization options (e.g. channel sizes)
- 🐛 Compatibility issues with some hardware interfaces
SynthMaster 2
From 451 App Store ratingsWhat we love
- 🚀 Best synth on iPad
- 👍 Delicious sound
- 👍 Tremendously powerful synth
- 👍 Great synth with complex possibilities and great sound(s)
- 👍 Perfeito
Room to improve
- 🐛 Auswahl der Modulationsquellen funktioniert nicht richtig
- 🐛 Echt schlecht
- 🐛 Broken Preset System for a powerful synth
- 🐛 Please fix the OSC behavior on Square and Saw
- 🐛 Preset issues
Bugs and requests
AUM
Reported bugs
3 issues- Crashes or freezes when using certain plugin combinations
- Compatibility issues with iOS 15 and newer
- Inconsistent MIDI transport controls
Requested features
4 requests- Add MIDI clock sync receive capability
- Implement a timeline/sequencer view
- Provide more visual customization options
- Improve support for external hardware integration
SynthMaster 2
Reported bugs
4 issues- Presets not loading correctly
- Modulation not working after loading project
- Skin resets to default
- App crashes frequently
Requested features
2 requests- Pitch bend/glide for imported samples
- Integration with AUM audio mixer
In-app purchases
AUM
- Small Tip$0.99
- Medium Tip$1.99
- Large Tip$4.99
Show 1 moreShow fewer
- Huge Tip$9.99
SynthMaster 2
- BigTone Tableworks Vol.2$1.99
- Burak Yeter Synth Sounds Vol1$1.99
- Aiyn Zahev Expansion 1$1.99
Show 29 moreShow fewer
- BigTone Tableworks Vol.1$1.99
- Michael Kastrup Expansion$1.99
- EDM Stars Volume 1$1.99
- Nori Ubukata Pop Hits Vol.4$1.99
- Rob Lee EDM Expansion Vol.2$1.99
- Alonso Sound Future Rave$1.99
- Nori Ubukata Pop Hits Vol.1$1.99
- BigTone Techno Bits Vol.1$1.99
- Club Sequences Vol.1$2.99
- Historical Synth Giants Vol.3$2.99
- Dawn of Electronic Music Vol.2$2.99
- Nori Ubukata Art Rock Basics$2.99
- BigTone Analog Basics 02$4.99
- BigTone Analog Basics$4.99
- BigTone Signature Sounds Vol.1$4.99
- NU Sounds of the World$4.99
- Historical Synth Giants Vol.4$4.99
- Historical Synth Giants Vol.1$4.99
- Historical Synth Giants Vol.2$4.99
- Japan Vintage$4.99
- NatLife Future Bass Sounds$4.99
- Danyella EDM Expansion Vol.1$4.99
- Dawn of Electronic Music Vol.1$4.99
- Dawn of Electronic Music Vol.3$4.99
- Rob Lee EDM Expansion Vol.3$4.99
- Natlife Disco Funk$4.99
- Insigne Essentials 4 Clubbin$4.99
- Desktop Presets Upgrade$9.99
- All Expansions Bundle$49.99









