Comparison

EQ550b vs GSDSP MMM

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

Head to head
About

EQ550b

This audio effect plugin emulates a classic American equalizer from the late 1960s, offering four bands of equalization with selectable frequencies and proportional Q. It provides a wide range of tonal variations for professional audio manipulation and can be used as a standalone app or an AUv3 plugin.

Highlights
  • Modeled vintage EQ
  • Four bands of equalization
  • Selectable frequency centers
  • Proportional Q filter
  • Stereo, Mid, or Side EQ modes
  • AUv3 plugin compatibility
Read full description

EQ550b AUv3 plug-in — comes as time-limited Demo-version for you to try. It gives you 5 minutes of Free play time. (You can reload the EQ550b AUv3 plug-in as many times as you want, thereby you get the Demo period again and again.) Unlimited version of EQ550b AUv3 plug-in comes as In-App Purchase. Based on Classic American EQ from the late '60s, the EQ550b is a continuation of the EQ that played a major role in the history of music recording, but with an additional filter band and several new frequencies. With a surprisingly wide range of tonal variations, the EQ550b is an invaluable and professional audio tool with great flexibility and excellent sonic ability. Features: • Standalone and AUv3 plug-in; • Precise port of Rack Extensions plug-in; • Modeled vintage EQ; • Four bands of classic American equalization; • Each band offers seven selected frequency centers; • 15 dB of boost/cut per band; • EQ band 1 and 4 offer shelf/peak switching; • Proportional Q narrows filter Q at extremes; • Stereo (Mono), Mid or Side EQ modes; • Undo/Redo; • A/B comparison; • 2x/4x/8x Upsampling; • Macro controllers; • Built-in Gain Match; • Scalable GUI. Rather than offer a huge assortment of complex features, the EQ550b provides exactly the right number of controls. Its four EQ bands are overlapped significantly to aid in dual roles as problem solver and sweetening device with each band offering seven switchable filter frequencies that span four-to-five octaves. These frequencies, purposely selected to be musical rather than numeric. Making use of Proportional Q intuitively widens the filter bandwidth at minimal settings and narrows it at higher settings without the need for additional bandwidth controls. This unique feature minimizes the «phase-shift» sound found in many equalizers. The EQ550b extends the features of the original hardware and joins the flexibility of the digital world to the character of the analog processing. Allows you to choose between equalizer modes (Stereo, Mid, Side) and remove analogue saturation from the processing circuit to deliver pure digital sound. To use EQ550b as a plug-in, you need an AUv3-compatible host app like GarageBand, Auria, AUM, Cubasis and more — EQ550b will appear in the list of Audio Unit extensions for effect plug-ins in the host app.

About

GSDSP MMM

This app offers a robust MIDI modulation engine for controlling various instruments and plugins. It allows users to create dynamic audio with LFOs, random sources, and more, featuring a performance-focused interface for live use.

Highlights
  • MIDI CC control for plugins and hardware
  • LFOs, random sources, and envelope followers
  • Audio-based modulation capabilities
  • Dedicated Performance Skin for live use
  • AUv3 audio effect plugin
  • Desktop versions for Windows and macOS
Features
Read full description

A powerful MIDI modulation engine for controlling plugins, hardware, and instruments using LFOs, random sources, macros, and audio-based modulation. Modulate Everything MMM is a MIDI controller and modulation workstation designed to control any parameter that accepts MIDI CC — software instruments, plugins, external hardware, or any MIDI-capable device. Create modulation using LFOs, Random Generators, Envelope Followers, XY pads, and more. No more drawing of automation curves, keep your audio dynamic and exciting with ease. Perform Live MMM includes a dedicated Performance Skin designed for low-light and stage environments. It uses a restrained, red-accented color palette that preserves focus and minimizes visual distraction while performing. The interface remains clear and readable in dark settings, ensuring stable workflow during your live performance. MMM vs MMMm MMM includes audio input, enabling Envelope Followers, audio-reactive modulation, and audio output — ideal when used as an audio plugin. MMMm, by contrast, is a MIDI-only FX version for hosts such as Logic Pro or AUM that require a pure MIDI processor. Both versions support MIDI input and output and provide the same core modulators. MMM is an AUv3 audio effect plugin compatible with Logic Pro, AUM, Cubasis, GarageBand and many more. A Desktop version is also available for Windows and macOS (VST3 / AU / AAX). More information here: https://gs-dsp.com/products So what are you waiting for?

Screenshots

EQ550b4 screens
GSDSP MMM4 screens

Verdict

The call

The clearest difference is in-app purchases: GSDSP MMM at none against EQ550b's 1. EQ550b's advantage is review sentiment (100% vs 67%) and update cadence (every 2 weeks vs every 5 weeks). On price, rating, ratings volume and ads 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

Both are free to download. EQ550b sells 1 one-off in-app purchase. GSDSP MMM asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for EQ550b against 4.7 for GSDSP MMM. Both are backed by a comparable volume of ratings — 14 and 36 respectively. Written reviews are what separate them: 100% of EQ550b's written reviews are positive against 67% of GSDSP MMM's.

UpkeepUpdate frequency

EQ550b ships an update every 2 weeks, GSDSP MMM every 5 weeks. Both last shipped on October 24, 2026.

Scorecard5 real differences · 5 level
EQ550b versus GSDSP MMM: the parameters behind the verdict, then further details
ParameterEQ550bGSDSP MMM
PriceFreeFree
Rating4.8 (14 ratings) — better4.7 (36 ratings)
Positive reviews100.0% of reviews — better66.7% of reviews
Number of ratings1436 — better
Update frequencyEvery 2 weeks — betterEvery 5 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10.0 — better13.0
Further details — not scored
Size19 MB65 MB
Age rating4+4+
DeveloperRRS, OOOGustav Scholda

Customer experience

EQ550b

All ratings13 ratings
Positive92.3%
Neutral7.7%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

GSDSP MMM

All ratings36 ratings
Positive94.4%
Neutral0.0%
Negative5.6%
Written reviews6 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

In-app purchases

1 purchases

EQ550b

One-time1
  • RRS EQ550b Unlimited$4.99
None

GSDSP MMM

No in-app purchases

Questions

Is EQ550b free?
EQ550b is free to download, with in-app purchases available.
Is GSDSP MMM free?
GSDSP MMM is free to download, with no in-app purchases.
Which has better reviews, EQ550b or GSDSP MMM?
EQ550b is rated higher. EQ550b averages 4.8 out of 5 from 14 ratings, while GSDSP MMM averages 4.7 from 36 ratings.
Do EQ550b or GSDSP MMM have ads?
Neither EQ550b nor GSDSP MMM shows ads.
Which is updated more often, EQ550b or GSDSP MMM?
EQ550b ships an update every 2 weeks, and GSDSP MMM every 5 weeks. Most recently, EQ550b was updated on October 24, 2026 and GSDSP MMM on October 24, 2026.

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