# KDJ vs EQ550

The clearest difference is in-app purchases: KDJ at none against EQ550's 1. KDJ also leads on review sentiment (67% vs 33%) and rating (4.8 vs 4.5). EQ550's advantage is update cadence (monthly vs every 3 months). On price, ratings volume, ads and device support there is nothing between them.

Both are free to download. EQ550 sells 1 one-off in-app purchase. KDJ asks for nothing beyond the download.

KDJ holds the better App Store score, 4.8 against 4.5. Both are backed by a comparable volume of ratings — 17 and 11 respectively. Written reviews point the same way: 67% of KDJ's written reviews are positive against 33% of EQ550's.

KDJ ships an update every 3 months, EQ550 monthly. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | KDJ | EQ550 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (17 ratings)](https://appshunter.io/ios/app/kdj-one/id1385367500/reviews)** | [4.5 (11 ratings)](https://appshunter.io/ios/app/eq550/id1507132030/reviews) |
| Number of ratings | **17** | 11 |
| Positive reviews | **66.7% of reviews** | 33.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 82 MB | 20 MB |
| Requires iOS | 10.0 | 10.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [CyberStep, Inc.](https://appshunter.io/developer/459682825) | [RRS, OOO](https://appshunter.io/developer/1486125568) |

## What reviewers say

### KDJ

[App page](https://appshunter.io/ios/app/kdj-one/id1385367500)

Create music on your smartphone with a portable audio workstation. Compose original songs or mix existing tracks using over 400 instruments and 200 preset samples. Ideal for beginners and on-the-go musicians.

**Highlights:** Compose music in 5 minutes, Over 200 preset tracks, Over 400 instruments, Sequencer, Synthesizer, Sampler modes, Song Mode for arrangement, Personal DJ machine functionality

**Features:** macOS Compatibility

**In-app purchases:** none


### EQ550

[App page](https://appshunter.io/ios/app/eq550/id1507132030)

This audio effect plugin emulates classic American EQs from the late 1960s, offering precise control over equalization with unique Proportional Q technology. It functions as a standalone app or an AUv3 plugin for compatible hosts, providing a flexible and characterful sound shaping experience.

**Highlights:** Standalone and AUv3 plugin, 3 bands of classic American equalization, Proportional Q filter bandwidth, Stereo, Mid, or Side EQ modes, Undo/Redo and A/B comparison, Scalable GUI

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RRS EQ550 Unlimited | $4.99 | one-time |


## Frequently asked questions

### Is KDJ free?

KDJ is free to download, with no in-app purchases.

### Is EQ550 free?

EQ550 is free to download, with in-app purchases available.

### Which has better reviews, KDJ or EQ550?

KDJ is rated higher. KDJ averages 4.8 out of 5 from 17 ratings, while EQ550 averages 4.5 from 11 ratings.

### Do KDJ or EQ550 have ads?

Neither KDJ nor EQ550 shows ads.

### Which is updated more often, KDJ or EQ550?

KDJ ships an update every 3 months, and EQ550 monthly. Most recently, KDJ was updated on October 25, 2026 and EQ550 on October 24, 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.*