# PX1 FM Synth > Dual-engine 6-operator FM synthesizer for iOS and macOS. (iPhone/iPad app by Peter Sjogren.) - Source: https://appshunter.io/ios/app/px1-fm-synth/id6785258298 (this page in markdown: same URL + `.md`) - Developer: [Peter Sjogren](https://appshunter.io/developer/1268263124) - Category: Music - Price: $14.99 - Rating: 5.00/5 from 2 App Store ratings - Age rating: 4+ - Requires: iOS 17.6 · 121 MB - Released: 2026-07-08 - Data updated: 2026-08-14 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/px1-fm-synth/id6785258298/reviews.md ## What is PX1 FM Synth? PX1 is a dual-engine FM synthesizer inspired by the classic 6-operator digital synths of the 1980s. Each engine features six operators, 32 algorithms, and full envelope control — giving you everything from glassy electric pianos and punchy basses to evolving pads and metallic bells. What makes PX1 special is the dual-engine architecture. Two completely independent FM voices run side by side. Copy one engine to the other, make subtle changes, then use the Spread control to place them across the stereo field. The result is a lush, wide sound that a single FM engine simply cannot produce. FEATURES • Two independent 6-operator FM engines • 32 classic FM algorithms • Per-operator envelopes (4 rates + 4 levels) • Per-operator pan for detailed stereo placement • Five macro knobs — Brightness, Touch, Attack, Decay, Spread • Copy/Paste between engines for instant layering • Random patch generator exploring the classic FM sound palette • Built-in reverb (Size, Damp, Amount) • Mono, Legato, and Portamento modes • LFO with triangle, saw, square, and random waveforms • Pitch bend range and transpose controls • Key velocity sensitivity per operator • Keyboard rate scaling and level scaling • Operator Key Sync on/off for consistent or organic attacks AUv3 PLUGIN PX1 works as a standalone instrument and as an Audio Unit v3 plugin. Load it directly inside GarageBand, Logic Pro, AUM, Cubasis, or any AUv3-compatible host. Full parameter automation is supported — record knob movements in your DAW and play them back. DESIGNED FOR MUSICIANS The interface stays close to the original FM programming model that experienced synthesists know, while macro controls make it approachable for anyone. Turn one knob and shape the entire sound; dive into individual operators when you want surgical control. LISTEN TO EXAMPLES Hear PX1 in action — sound demos are available at: https://soundcloud.com/peter-sj-gren/sets/px1-demo Requires no in-app purchases. No subscriptions. No ads. No tracking. ## Key features - Dual independent 6-operator FM engines - 32 classic FM algorithms - Per-operator envelopes and pan - Five macro knobs for sound shaping - Built-in reverb - AUv3 plugin support - Random patch generator ## Frequently asked questions about PX1 FM Synth ### What kind of sounds can PX1 FM Synth create? PX1 FM Synth excels at producing a wide range of classic FM sounds. Users can create everything from glassy electric pianos and punchy basses to evolving pads and metallic bells, thanks to its dual-engine architecture and extensive operator controls. ### Does PX1 FM Synth work with other music apps? Yes, PX1 FM Synth functions as a standalone instrument and also as an Audio Unit v3 (AUv3) plugin. It can be loaded directly into compatible hosts like GarageBand, Logic Pro, AUM, and Cubasis, allowing for full parameter automation within your DAW. ### How does PX1 FM Synth handle stereo imaging? PX1 FM Synth's dual-engine architecture is specifically designed for rich, wide stereo sounds. Each engine has per-operator pan controls, and the 'Spread' macro knob allows for detailed stereo placement, creating a lush soundscape that a single engine cannot achieve. ### Is PX1 FM Synth easy to use for beginners? While the interface stays close to traditional FM programming for experienced synthesists, PX1 FM Synth includes five macro knobs. These controls allow users to shape the entire sound with a single knob, making it approachable for those new to FM synthesis. ### What platforms is PX1 FM Synth available on? PX1 FM Synth is available for macOS, iPhone, and iPad, making it a versatile tool for musicians across different Apple devices. It leverages the AUv3 plugin format for seamless integration into iOS and macOS music production workflows. ### Does PX1 FM Synth have ads? No, PX1 FM Synth does not contain advertisements. The app is designed to be a focused creative tool without interruptions from ads. ### What is the update frequency for PX1 FM Synth? PX1 FM Synth was last updated on 2026-07-08, with its initial release on the same date. As a paid application with a focus on core functionality, updates are typically released to add features or improve stability based on user feedback and platform changes. ### What is the price of PX1 FM Synth? PX1 FM Synth is a paid application priced at $14.99. There are no in-app purchases or subscriptions required to access its full functionality. ## Version history (last 3 releases) ### 1.0.2 — 2026-08-11 * Added more patches in the PX1 folder * Show loaded patch name in PX1 tracks in Logic/GarageBand documents * Transpose parameter for both engines independently ### 1.0.1 — 2026-08-06 * Fixed a iPhone GarageBand hanging note bug * Low latency in standalone app ### 1.0 — 2026-07-08 No release notes. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-14.*