Comparison

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.

Head to head
About

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.

Highlights
  • Mono to stereo conversion
  • Adjustable stereo width
  • Optional LFO modulation
  • Micro-delay de-correlators
  • Creates natural spatial depth
  • No pitch shifting or echo
Features
Read full description

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.

About

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.

Highlights
  • 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
Features
Read full description

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

Stereo Modulator3 screens
JAX Stereo Tool (AU)4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard6 real differences · 4 level
Stereo Modulator versus JAX Stereo Tool (AU): the parameters behind the verdict, then further details
ParameterStereo ModulatorJAX Stereo Tool (AU)
Price$2.99 — better$5.99
Rating5.0 (3 ratings) — better4.4 (27 ratings)
Positive reviews100.0% of reviews — better80.0% of reviews
Number of ratings327 — better
Update frequencyEvery 3 monthsEvery 11 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10.0 — better12.0
Further details — not scored
Size2 MB10 MB
Age rating4+4+
DeveloperBlue Mangoo Consulting Company LimitedJens Guell

Customer experience

Stereo Modulator

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

JAX Stereo Tool (AU)

All ratings27 ratings
Positive85.2%
Neutral0.0%
Negative14.8%
Written reviews10 reviews
Positive80.0%
Neutral0.0%
Negative20.0%

In-app purchases

None

Stereo Modulator

No in-app purchases

None

JAX Stereo Tool (AU)

No in-app purchases

Questions

Is Stereo Modulator free?
Stereo Modulator costs $2.99, with no in-app purchases.
Is JAX Stereo Tool (AU) free?
JAX Stereo Tool (AU) costs $5.99, with no in-app purchases.
Which has better reviews, Stereo Modulator or JAX Stereo Tool (AU)?
Stereo Modulator is rated higher. Stereo Modulator averages 5.0 out of 5 from 3 ratings, while JAX Stereo Tool (AU) averages 4.4 from 27 ratings.
Do Stereo Modulator or JAX Stereo Tool (AU) have ads?
Neither Stereo Modulator nor JAX Stereo Tool (AU) shows ads.
Which is updated more often, Stereo Modulator or JAX Stereo Tool (AU)?
Stereo Modulator ships an update every 3 months, and JAX Stereo Tool (AU) every 11 days. Most recently, Stereo Modulator was updated on August 30, 2026 and JAX Stereo Tool (AU) on September 23, 2026.

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