Stereo Modulator vs JAX Stereo Tool (AU)
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Stereo Modulator
This audio effect plugin transforms mono sound into stereo, adding width and depth. It uses micro-delays to create a natural sense of space, with optional LFO modulation for a Leslie speaker-like effect without pitch shifting. Ideal for creating separation in mixes, especially for guitars and vocals.
- Mono to stereo conversion
- Adjustable stereo width
- Optional LFO modulation
- Micro-delay de-correlators
- Creates natural spatial depth
- No pitch shifting or echo
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Stereo Modulator is an AU3 effect that converts mono sound into stereo, with an adjustable width and optional LFO modulation. It works by using a bank of randomized stereo de-correlators that apply micro-delays to introduce random differences between the spectrums of the left and right audio channels. In its output we hear a natural sense of space that is not present in mono recordings. It's similar to the sound space one gets from using a stereo reverb plugin except that it is tight and clear, without echo. It can operate either as a static effect or it can be gently modulated by a low-frequency oscillator. The modulation is akin to the sound of a Leslie speaker, except that it doesn't do any pitch shifting, so the output remains focused and tuning is not compromised. This effect is especially useful for mixing overdriven electric guitar sounds together with vocals. Using Stereo Modulator on the guitars, we can push them out to the sides, creating a space in the centre for the vocal to cut through, without needing to reduce the volume of the guitars. NOTE: Stereo Modulator is an AU3 plugin only, not a standalone app. To use it, you will need an audio unit host app such as Garageband or Audiobus.
JAX Stereo Tool (AU)
This audio processing tool allows users to visually manipulate the stereo image of digital audio. It functions as a mastering effect, enabling real-time adjustment of stereo width and the recovery of mono compatibility. The app includes a correlograph for visual feedback and optimization.
- Visual stereo image manipulation
- Real-time stereo width adjustment
- Mono compatibility recovery
- Integrated correlograph for visual feedback
- Audio Unit (AUv3) plugin format
- System-wide availability
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JAX Stereo Tool is a visual Audio Unit plugin for manipulating the stereo image of digital audio. The distribution app comes with an embedded plug-in (Audio Unit) that is available system-wide when you install the app. You should be able to use it with most supporting host applications. Audio Units are Apple's recommended method for providing shared audio effects for applications and audio editors. You can load the plugin into any host application that supports at least stereophonic audio effect plug-ins (in Audio Unit format - AUv3) with its own user interface. JAX Stereo Tool has its main use as a mastering effect, that allows you to modify the stereo image of your audio by narrowing or widening it in a controlled manner. That is, the stereo output can be continuously adjusted in the basic function of pure mono to very wide stereo. This happens in real time and you can observe the result with the integrated correlograph, controlling and optimizing the audio thanks to this helpful additional visual information. One of the special functions of JAX Stereo Toolis to recover lost mono-compatibility. This technique is conceptually quite simple and effective but somewhat difficult to understand. Please read the manual for further details. The manual is shipped with the app or available on the product website at https://audio.digitster.com
Screenshots
Verdict
The clearest difference is rating: Stereo Modulator at 5.0 against JAX Stereo Tool (AU)'s 4.4. Stereo Modulator also leads on review sentiment (100% vs 80%) and price ($2.99 vs $5.99). JAX Stereo Tool (AU)'s advantage is update cadence (every 11 days vs every 3 months) and ratings volume (27 vs 3). On ads, in-app purchases, monetization model 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
Stereo Modulator costs $2.99 and JAX Stereo Tool (AU) $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Stereo Modulator holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: JAX Stereo Tool (AU) has 27 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 100% of Stereo Modulator's written reviews are positive against 80% of JAX Stereo Tool (AU)'s.
Stereo Modulator ships an update every 3 months, JAX Stereo Tool (AU) every 11 days. The most recent releases landed on August 30, 2026 and September 23, 2026 respectively.
| Parameter | Stereo Modulator | JAX Stereo Tool (AU) |
|---|---|---|
| Price | $2.99 — better | $5.99 |
| Rating | 5.0 (3 ratings) — better | 4.4 (27 ratings) |
| Positive reviews | 100.0% of reviews — better | 80.0% of reviews |
| Number of ratings | 3 | 27 — better |
| Update frequency | Every 3 months | Every 11 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 10.0 — better | 12.0 |
| Further details — not scored | ||
| Size | 2 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Blue Mangoo Consulting Company Limited | Jens Guell |
Customer experience
Stereo Modulator
JAX Stereo Tool (AU)
In-app purchases
Stereo Modulator
No in-app purchases
JAX Stereo Tool (AU)
No in-app purchases
Questions
Is Stereo Modulator free?
Is JAX Stereo Tool (AU) free?
Which has better reviews, Stereo Modulator or JAX Stereo Tool (AU)?
Do Stereo Modulator or JAX Stereo Tool (AU) have ads?
Which is updated more often, Stereo Modulator or JAX Stereo Tool (AU)?
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