Harmony Voice vs SynthMaster One
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Harmony Voice
Create a vocal choir from your own voice with up to four harmonized parts. This app offers real-time pitch correction, automatic chord generation, and voice character modification. Enhance your singing with professional effects and easily record and export your creations.
- Four-part real-time harmonizer
- Automatic tuning correction
- Manual and automatic harmonization modes
- Voice character adjustment
- Hi-end reverb and chorus effects
- Audio recorder with metronome
- SoundCloud upload and file export
Read full descriptionHide full description
Transform your voice into a choir with up to four voices ! Harmony Voice is a pitch shifter and harmonizer with professional features including automatic tuning correction. A realtime visual intonation-display gives you feedback of the tunes you sing. You can sing and Harmony voice will add up to four voices according to the chords you play with the piano keyboard. Instead of playing the chords yourself you can let Harmony Voice play the chords automatically to enrich the sound of your voice in a musically pleasant way. The voice character can be adjusted in a way that you can turn a female voice into a male voice and the other way round. Features: • Four part realtime Harmonizer / Pitch corrector • Different Harmonizer modes: - Manual harmonization by playing chords with up to four notes while singing - Automatic harmonization ( Kraehenbuehl ) - Play base note and Harmony Voice adds appropriate chords - Directly play the tunes for up to four voices with the keyboard. • Select key note and scale for harmonization and pitch correction. • Harmonies can be in just ( Barbershop ) or tempered tuning. • Mix your original voice with the harmonized parts. • Change the voice character. • Play background track from your iTunes library. • Hi-end reverb effect for room simulation. • Chorus and Delay effect. • Audiobus 2 support (Input/Filter/Output) (requires iOS 7 or newer) • Use a CoreMIDI compatible Interface to control Harmony Voice with a MIDI Keyboard. • Audio recorder with Metronome. • Upload to SoundCloud and File Export. • Audio pasteboard for exporting to other Apps Headphones are required to avoid feedback. Headsets with mic work great, for best quality we recommend IK Multimedia's iRig Mic.
SynthMaster One
This powerful wavetable synthesizer app offers an intuitive workflow for creating unique sounds. It features a rich library of wavetables, inspiring presets, and a semi-modular architecture for deep sound design. Easily sync data across devices and integrate with DAWs.
- Wavetable synthesis
- Semi-modular architecture
- 650 factory presets
- AUv3 support
- Cross-platform cloud sync
- Real-time modulation feedback
- 32-step arpeggiator/sequencer
Read full descriptionHide full description
SynthMaster One iOS is KV331 Audio's first full blown universal synth app on iOS platform. It's a powerful wavetable synth with an intuitive workflow. With its simple layout, rich wavetable/waveform content and inspiring factory presets library, designing new sounds with SynthMaster One iOS is a joy. SynthMaster One iOS is feature wise identical to the desktop version except the following: * 16 voice polyphony (32 for the desktop version) * Comes with 650 presets (1250 for the desktop version) FEATURES * Universal App: SynthMaster One is now a universal standalone/AUv3 synth app running on iPhone 7 and above. * 650 Factory Presets: SynthMaster One iOS comes with inspiring factory presets from a world class team of sound designers: Arksun, Aiyn Zahev, BigTone Studios, Brian Transeau, Bluffmunkey, Bulent Biyikoglu, Gercek Dorman, Dejavu Sound, Fragment Audio, Kurt Ader, Mirko Ruta, Nori Ubukata, Rob Lee, Ufuk Kevser, Selcuk Ergen, The Machine, Vandalism Sound, Venus Theory, Vorpalsound and Xenos Soundworks * AUv3: SynthMaster One iOS supports AudioUnits V3, allowing multiple instances to run under supporting DAW apps like GarageBand, Cubasis or Beat Maker. * Files App Integration: Easily import/export presets, waveforms or scales using the common file browser UI (requires iOS 11+). * Real-time Modulation Feedback: See in real-time how modulation sources and targets change. This is a very helpful feature when designing sounds! * Cross Platform Cloud Synchronization: Easily synchronize your SynthMaster One related data across multiple platforms (Windows, MacOS, iPad, iPhone) * Semi-Modular Architecture: For each SynthMaster One instance, there are 2 oscillators with 2 sub oscillators, 2 Filters, 4 ADSR Envelopes, 3 LFOs, a powerful 16 step arpeggiator/sequencer and also 11 different effects that can be inserted on to 6 FX insert slots. The sub oscillators can be connected to the oscillators in 5 different modes which let you use it as a regular sub oscillator or do complex modulations such as ring modulation, amplitude modulation, phase modulation or frequency modulation. * 32 Step Arpeggiator/Sequencer: The arpeggiator in SynthMaster One features classic arpeggiator modes such as Up, Down, UpDown, DownUp, UpDown2, DownUp2, AsPlayed as well as Sequence, Chord and Arpeggiate modes. * Wavetable Synthesis: SynthMaster One implements true wavetable synthesis which opens up new possibilities for sound design. It comes with a rich content library with hundreds of waveforms and wavetables. * Stereo Oscillators with up to 16 voices Unison: Each of the 2 oscillators in SynthMaster One have stereo output, and can have up to 16 voices "unison". Using the "voices", "voices mix", "detune curve", "detune spread", "pan stread", "tone spread" and "phase spread" parameters, each oscillator can generate a rich "supersaw" type sound. * Zero Delay Feedback Filters: All of the 4 filter categories in SynthMaster One are developed using the zero delay feedback filter technology. With advanced filter parameters like input gain, drive, acid, filter nonlinearities and up to 4 times oversampling you can get that "analog" sound from the filters! * Rich Set of Effects: SynthMaster One features 11 different effect types: Distortion, LoFi, Ensemble, Phaser, 6 Band EQ, Compressor, Vocoder, Delay, Chorus, Tremolo, Reverb. * Microtuning: SynthMaster One supports Scala tuning, so tuning can be set either for each preset or globally by loading from a Scala tuning file. SynthMaster One comes with 300+ scales ranging from 5 note equal tempered scales to 12 note alternate tuning scales. * Preset Browser: SynthMaster One features a comprehensive preset browser with separate search criterias for instrument type, preset attributes, music style or preset author. SUPPORTS * All 64-bit iPad devices * AUv3 Audio Unit Extensions * Note-per-channel MIDI controllers (MPE) * Ableton Link * Bluetooth LE MIDI Controllers * AirDrop
Screenshots
Verdict
The clearest difference is rating: SynthMaster One at 4.7 against Harmony Voice's 2.3. SynthMaster One also leads on review sentiment (64% vs 33%) and ratings volume (743 vs 24). Harmony Voice's advantage is in-app purchases (none vs 11) and price ($4.99 vs $9.99). 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
Harmony Voice costs $4.99 and SynthMaster One $9.99 up front. SynthMaster One sells 11 one-off in-app purchases. Harmony Voice asks for nothing beyond the download.
SynthMaster One holds the better App Store score, 4.7 against 2.3. That said, the two scores are not equally well evidenced: SynthMaster One has 743 ratings behind it against 24, so its average is the more settled of the two. Written reviews point the same way: 33% of Harmony Voice's written reviews are positive against 64% of SynthMaster One's.
Harmony Voice ships an update every 6 months, SynthMaster One every 2 months. The most recent releases landed on September 26, 2026 and September 28, 2026 respectively.
| Parameter | Harmony Voice | SynthMaster One |
|---|---|---|
| Price | $4.99 — better | $9.99 |
| Rating | 2.3 (24 ratings) | 4.7 (743 ratings) — better |
| Positive reviews | 33.3% of reviews | 63.8% of reviews — better |
| Number of ratings | 24 | 743 — better |
| Update frequency | Every 6 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free with in-app purchases — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 8.0 — better | 10.0 |
| Further details — not scored | ||
| Size | 28 MB | 402 MB |
| Age rating | 4+ | 4+ |
| Developer | Harry Gohs | KV331 Audio |
Customer experience
Harmony Voice
SynthMaster One
Bugs and requests
Harmony Voice
Not enough reviews yet to summarise bugs or requests.
SynthMaster One
Reported bugs
4 issues- Stuck notes and MIDI issues
- Preset loading crashes
- Restore purchases not working
- Incompatibility with certain DAWs
Requested features
4 requests- Add custom wavetable support
- Improve MIDI mapping and MPE functionality
- Optimize performance on older devices
- Streamline preset management and browsing
In-app purchases
Harmony Voice
No in-app purchases
SynthMaster One
- BigTone Club Construction Set$4.99
- True Trance Sounds Volume 1$4.99
- Vandalism Future House$4.99
Show 8 moreShow fewer
- NatLife Retrowave Sounds Vol.1$4.99
- Demis Hellen Euphoric Trance$4.99
- Venus Theory Trap Sounds$4.99
- Vandalism Shocking Future Bass$4.99
- NatLife Progressive&Deep Vol.1$4.99
- Bluffmunkey Cinematic Sounds$4.99
- Desktop Presets Upgrade$7.99
- SM One Expansions Bundle$24.99









