Comparison

amoenus externus vs PX1 FM Synth

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

amoenus externus

Features
Read full description

amoenus externus transforms your headphone listening into a natural speaker experience. Using a carefully tuned arrangement of 9 ultra-short delays, it recreates the acoustic perception of a classic stereo speaker triangle — placing the sound naturally in front of you, slightly outside your head, rather than inside it. No artificial reverb. No coloration. Just a more natural, fatigue-free headphone sound. Compatible with foobar2000 (v2.25+), AUM, GarageBand, and all AUv3-compatible hosts on iOS.

About

PX1 FM Synth

Create rich, wide stereo sounds with a dual-engine FM synthesizer. Explore classic 1980s digital synth tones, from electric pianos to metallic bells, with extensive operator and envelope controls. It functions as a standalone app or an AUv3 plugin for music production.

Highlights
  • 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
Features
Read full description

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.

Screenshots

amoenus externus4 screens
PX1 FM Synth4 screens

Verdict

The call

The clearest difference is price: amoenus externus at $2.99 against PX1 FM Synth's $7.99. amoenus externus also leads on iOS requirement (12.0 vs 17.6). On update cadence, ads, in-app purchases 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

amoenus externus costs $2.99 and PX1 FM Synth $7.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

amoenus externus ships an update fortnightly, PX1 FM Synth every 2 weeks. The most recent releases landed on October 30, 2026 and November 5, 2026 respectively.

Scorecard2 real differences · 7 level
amoenus externus versus PX1 FM Synth: the parameters behind the verdict, then further details
Parameteramoenus externusPX1 FM Synth
Price$2.99 — better$7.99
Rating—5.0 (2 ratings) — better
Number of ratings—2 — better
Update frequencyFortnightly — betterEvery 2 weeks
AdsNoNo
In-app purchasesNoNo
Monetization—Paid
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS12.0 — better17.6
Further details — not scored
Size8 MB121 MB
Age rating4+4+
DeveloperErich MeierPeter Sjogren

In-app purchases

None

amoenus externus

No in-app purchases

None

PX1 FM Synth

No in-app purchases

Questions

Is amoenus externus free?
amoenus externus costs $2.99, with no in-app purchases.
Is PX1 FM Synth free?
PX1 FM Synth costs $7.99, with no in-app purchases.
Do amoenus externus or PX1 FM Synth have ads?
Neither amoenus externus nor PX1 FM Synth shows ads.
Which is updated more often, amoenus externus or PX1 FM Synth?
amoenus externus ships an update fortnightly, and PX1 FM Synth every 2 weeks. Most recently, amoenus externus was updated on October 30, 2026 and PX1 FM Synth on November 5, 2026.

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