# EQ550b vs GSDSP MMM

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.

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

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 35 respectively. Written reviews are what separate them: 100% of EQ550b's written reviews are positive against 67% of GSDSP MMM's.

EQ550b ships an update every 2 weeks, GSDSP MMM every 5 weeks. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | EQ550b | GSDSP MMM |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (14 ratings)](https://appshunter.io/ios/app/eq550b/id1507176549/reviews)** | [4.7 (35 ratings)](https://appshunter.io/ios/app/gsdsp-mmm/id6443846329/reviews) |
| Number of ratings | 14 | **35** |
| Positive reviews | **100.0% of reviews** | 66.7% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 5 weeks |
| Monetization | Free with in-app purchases | **Free** |
| Size | 19 MB | 65 MB |
| Requires iOS | **10.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [RRS, OOO](https://appshunter.io/developer/1486125568) | [Gustav Scholda](https://appshunter.io/developer/1642323227) |

## What reviewers say

### EQ550b

[App page](https://appshunter.io/ios/app/eq550b/id1507176549)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RRS EQ550b Unlimited | $4.99 | one-time |


### GSDSP MMM

[App page](https://appshunter.io/ios/app/gsdsp-mmm/id6443846329)

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:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked 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 35 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 25, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*