EQ550

EQ550

Classic American EQ

11 ratings
3 reviews
Free
In-App Purchases

Details

  • Released
  • Updated
  • April 10, 2020
  • January 2, 2026
EQ550 screenshot #1 for iPhone
EQ550 screenshot #2 for iPhone
EQ550 screenshot #3 for iPhone
EQ550 screenshot #4 for iPhone
EQ550 screenshot #5 for iPhone
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About

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.

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
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What's New in EQ550

3.0.3

January 2, 2026

- Fixed parameters Automation bug. If you like EQ550 plug-in, please support us by rating this app in the App Store!

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In-App Purchases

$4.99

RRS EQ550 Unlimited

RRS EQ550 Unlimited

User reviews

Needs a MacOS release to be realistically usable

Title says it all. I like this as a 550A emulator, especially for the price. Pretty nice features and interface, although I don’t love the curve in the saturation knob. Basically goes from no audible difference to total fuzz in like one notch. Feels like they used a virtual “linear pot” where a log would have been the ticket. I also would like an option to use stepped gain values like on an actual 550. All that said, the sound of this thing is pretty nice.

BUT. The lack of a version for MacOS cripples this plugin. Using more than a few instances on a project quickly overloads my iPad, forcing me to try to port it to my laptop in order to keep moving forwards. Then I find out all my plugins are disabled with no hope of using them. This, imo, is a major oversight and it relegates this from tool to toy status. Yes, I know it’s just GarageBand, but come on.
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Great!

These guys kill it with every app they make. IMHO they are underpriced. Sound great, easy to use, get them all! New synth kicks!

Sounds amazing until..

Loading this breaks my whole garageband session now. There’s just a high pitched click and then everything goes silent. The only way to fix it is to start a new project without loading this eq.. so it’s kinda useless

Developer apps

FAQ

How long can I use the EQ550 demo?

The EQ550 offers a time-limited demo version with 5 minutes of free play time. You can repeatedly reload the plugin to access this demo period again.

What is the full price of EQ550?

The unlimited version of the EQ550 AUv3 plugin is available as an in-app purchase. The specific price for the full version is not detailed in the provided data.

Does EQ550 have ads?

No, EQ550 does not contain advertisements. The app is free to download and use in its demo mode, with the full functionality unlocked via an in-app purchase.

What devices is EQ550 compatible with?

EQ550 is supported on iPhone, iPad, and iPod. It requires an AUv3-compatible host app to function as a plugin.

What is the age rating for EQ550?

EQ550 has an age rating of 4+. This indicates it is suitable for users of all ages, with no mature content concerns.

How often is EQ550 updated?

The latest version of EQ550 is 3.0.3, last updated on January 2, 2026. This suggests a relatively recent update, though specific update frequency is not detailed.

What makes EQ550's Proportional Q unique?

The Proportional Q feature intuitively widens filter bandwidth at minimal settings and narrows it at higher settings. This unique characteristic minimizes the 'phase-shift' sound often found in other equalizers.

Can EQ550 be used without a host app?

Yes, EQ550 can be used as a standalone application. It also functions as an AUv3 plugin within compatible host applications like GarageBand, Auria, AUM, and Cubasis.