# AX vs HARMONY DSP

The clearest difference is update cadence: AX at every 2 months against HARMONY DSP's every 19 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

AX ships an update every 2 months, HARMONY DSP every 19 months. The most recent releases landed on October 3, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | AX | HARMONY DSP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.2 (5 ratings)](https://appshunter.io/ios/app/ax-dsp-xl/id1495854432/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 19 months |
| Monetization | Free | — |
| Size | 10 MB | 3 MB |
| Requires iOS | 12.1 | **11.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Metra Electronics Corp.](https://appshunter.io/developer/1133973919) | [APEX Italy](https://appshunter.io/developer/1446565085) |

## What reviewers say

### AX

[App page](https://appshunter.io/ios/app/ax-dsp-xl/id1495854432)

Enhance your car's audio system with this digital signal processor. It offers an all-in-one solution for various audio setups, allowing for improved sound quality and subwoofer integration while preserving factory features. Control settings easily via a smartphone app.

**Highlights:** Digital Signal Processor, Subwoofer integration, Preserves OE features, Bluetooth smartphone control, Vehicle-specific T-Harnesses (sold separately), All-in-one solution

**Features:** macOS Compatibility

**In-app purchases:** none


### HARMONY DSP

[App page](https://appshunter.io/ios/app/harmony-dsp/id1638244924)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is AX free?

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

### Is HARMONY DSP free?

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

### Do AX or HARMONY DSP have ads?

Neither AX nor HARMONY DSP shows ads.

### Which is updated more often, AX or HARMONY DSP?

AX ships an update every 2 months, and HARMONY DSP every 19 months. Most recently, AX was updated on October 3, 2026 and HARMONY DSP on October 27, 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.*