Comparison

Stereo Modulator vs SL Tune

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

SL Tune

This app offers vocal pitch and tone effects for iPad, providing quick corrective or creative processing. It features fast pitch correction, modern vocal tone shaping, and mix control for flexible audio manipulation. It supports AUv3 for integration with compatible music hosts.

Highlights
  • Fast pitch correction
  • Modern vocal tone shaping
  • Mix control
  • Factory and user presets
  • AUv3 support
Features
Read full description

SL Tune is a vocal pitch-correction and tone effect for iPhone and iPad. Insert it on a vocal track in a compatible AUv3 host. Choose a key and scale, or select the allowed notes yourself. Natural mode preserves small pitch movements, Hard gives faster correction, and Robot locks pitch to the selected root across octaves. Six controls shape the sound: Retune, Humanize, Formant, Snap, Echo and Mix. Formant changes the tonal balance. Mix blends processed and original audio. Start with one of six factory presets: Classic Hard, Trap Lock, Silk Vocal, Clean Fix, Robot Grid and Echo Adlib. Save and load your own presets locally. The resizable interface adapts to portrait, landscape and compact host windows. Use SL Tune as an AUv3 effect in a compatible music host, or open the standalone app to preview and adjust the controls. Pitch correction works best on a single vocal line. It is not designed to tune a complete mix or separate voices from background music.

Screenshots

Stereo Modulator3 screens
SL Tune3 screens

Verdict

The call

The clearest difference is update cadence: SL Tune at every 9 days against Stereo Modulator's every 3 months. Stereo Modulator's advantage is price ($2.99 vs $7.99) and ratings volume (3 vs 1). On rating, review sentiment, ads and in-app purchases 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 SL Tune $7.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Stereo Modulator against 5.0 for SL Tune. Both are backed by a comparable volume of ratings — 3 and 1 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

Stereo Modulator ships an update every 3 months, SL Tune every 9 days. Both last shipped on October 24, 2026.

Scorecard4 real differences · 6 level
Stereo Modulator versus SL Tune: the parameters behind the verdict, then further details
ParameterStereo ModulatorSL Tune
Price$2.99 — better$7.99
Rating5.0 (3 ratings)5.0 (1 ratings)
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings3 — better1
Update frequencyEvery 3 monthsEvery 9 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10.0 — better15.0
Further details — not scored
Size2 MB37 MB
Age rating4+4+
DeveloperBlue Mangoo Consulting Company LimitedVIACHESLAV ZHILTSOV

Customer experience

Stereo Modulator

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

SL Tune

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Stereo Modulator

No in-app purchases

None

SL Tune

No in-app purchases

Questions

Is Stereo Modulator free?
Stereo Modulator costs $2.99, with no in-app purchases.
Is SL Tune free?
SL Tune costs $7.99, with no in-app purchases.
Which has better reviews, Stereo Modulator or SL Tune?
Stereo Modulator and SL Tune are both rated 5.0 out of 5 on the App Store, from 3 and 1 ratings respectively.
Do Stereo Modulator or SL Tune have ads?
Neither Stereo Modulator nor SL Tune shows ads.
Which is updated more often, Stereo Modulator or SL Tune?
Stereo Modulator ships an update every 3 months, and SL Tune every 9 days. Most recently, Stereo Modulator was updated on October 24, 2026 and SL Tune on October 24, 2026.

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