JAX Unisonic (Audio Unit) vs SL Echo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
JAX Unisonic (Audio Unit)
This audio unit generates up to 8 additional voices from any audio input by multiplying and shifting pitch. It simulates analog synthesizer unison effects for fattening sounds and adding presence, with individual voice transposition capabilities.
- Generates up to 8 additional voices
- Multiplies and shifts audio input pitch
- Simulates analog synthesizer unison effects
- Individual voice transposition (+/- 1 octave)
- Time domain pitch shifting (low latency)
- Panorama spread for voices
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JAX Unisonic is a special Audio Unit, able to produce up to 8 additional voices from any audio input (also polyphonic audio) by multiplying and shifting it in pitch and other parameters. Audio Units require a host application for operation. The concept of JAX Unisonic is loosely derived from ‘Unison’ which was adopted from the ancient analog synthesizer world, where manufacturers and sound designers intended to fatten the sound by multiplying and stacking available voices together. Also digital synthesizers did adopt this technique to fatten sound sources. Due to the instability of analog oscillators and components and some wilful detuning, an interesting sonic effect is achieved, giving the produced tones significantly more presence and life. Unison voices are still excessively used in modern music styles today. (In classical music compositions ‘unisono’ basically means a performance, where multiple instruments or voices play the same parts in an ensemble fashion.) Technical Now JAX Unisonic can simulate this sonic effect with any audio source by incorporating a bank of independent time domain pitch shifters, that are optimized to detune and spread artificially multiplied voices in panorama. It can be understood as a kind of super chorus generator or an ensemble like effect with variable, realtime controlled intensity and pitch relation. But it is clearly something more. With JAX Unisonic you can create up to 8 additional voices, that will be passed thru a chain of pitching and positioning, creating massively fattened sounds with any kind of voice input. Additionally you may transpose each voice individually per semitone to max. +/- 1 octave, something that cannot be achieved with usual choruses, unison or ensemble effects and moves the results slightly in the direction of the category “harmonizer” effects. Although the harmonic results can be programmed (automated) freely and are not auto generated in any way, as on some available other harmonizers. The used pitch shifters in our JAX Unisonic are NOT based on the phase vocoder paradigm (FFT) and do not introduce the static latencies, which are unavoidable by the latter. A time domain pitch shifter in contradiction, uses very small delay buffers, where the latency is dynamically adjusted (dependent on the used pitch shifting amount) and much smaller and nearly latency-free. Such pitch shifters are better situated for live usage therefore. Although, such pitch shifters sound slightly more raw and tend to produce disharmonic overtones with more extreme values. Usage JAX Unisonic may be used as a massive unison effect generator or more decently for creating various, more subtile effects for improving sonic qualities of parts in a composition. For instance controlled voice detuning, manual pitch correction, doubling of vocals or solo instruments or just to give some boring voices more interest and static sound some special movement. It is even usable with drums, adding subtile or even massive new frequency components.
SL Echo
This audio effect app provides animated delay and space for musical decisions on iPad. Easily adjust time, feedback, and tone for various repeat styles, while maintaining a clear dry signal with stereo width and ducking. It supports AUv3 integration with popular music hosts.
- Animated delay and space effects
- Adjustable time and feedback
- Tone shaping controls
- Stereo width and ducking
- AUv3 support
- Standalone preview mode
- Factory and user presets
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SL Echo is a focused AUv3 delay effect designed for fast musical decisions on iPad. Move from a close vocal pocket to wide, evolving repeats without navigating complex pages. • Time and feedback for slapback or long trails • Tone shaping for darker or brighter repeats • Stereo width and ducking for a clear dry signal • Factory presets and local user presets • AUv3 support for compatible iPad music hosts Works as a standalone preview app and as an AUv3 effect in GarageBand, AUM, Cubasis, BeatMaker 3 and other compatible hosts.
Screenshots
Verdict
The clearest difference is rating: SL Echo at 5.0 against JAX Unisonic (Audio Unit)'s 3.9. SL Echo also leads on price ($6.99 vs $9.99). JAX Unisonic (Audio Unit)'s advantage is ratings volume (9 vs 1) and iOS requirement (12.0 vs 15.0). On update cadence, ads, 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
JAX Unisonic (Audio Unit) costs $9.99 and SL Echo $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.
SL Echo holds the better App Store score, 5.0 against 3.9. That said, the two scores are not equally well evidenced: JAX Unisonic (Audio Unit) has 9 ratings behind it against 1, so its average is the more settled of the two.
JAX Unisonic (Audio Unit) ships an update every 5 days, SL Echo weekly. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.
| Parameter | JAX Unisonic (Audio Unit) | SL Echo |
|---|---|---|
| Price | $9.99 | $6.99 — better |
| Rating | 3.9 (9 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 44.4% of reviews | — |
| Number of ratings | 9 — better | 1 |
| Update frequency | Every 5 days — better | Weekly |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 40 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Jens Guell | VIACHESLAV ZHILTSOV |
Customer experience
JAX Unisonic (Audio Unit)
SL Echo
In-app purchases
JAX Unisonic (Audio Unit)
No in-app purchases
SL Echo
No in-app purchases
Questions
Is JAX Unisonic (Audio Unit) free?
Is SL Echo free?
Which has better reviews, JAX Unisonic (Audio Unit) or SL Echo?
Do JAX Unisonic (Audio Unit) or SL Echo have ads?
Which is updated more often, JAX Unisonic (Audio Unit) or SL Echo?
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