# AX vs Author BT Update

The clearest difference is update cadence: Author BT Update at monthly against AX's every 2 months. AX's advantage is device support (3 vs 1) and iOS requirement (12.1 vs 16.0). On price, ads and in-app purchases 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, Author BT Update monthly. The most recent releases landed on October 3, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | AX | Author BT Update |
| --- | --- | --- |
| 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 | **Monthly** |
| Monetization | Free | — |
| Size | 10 MB | 4 MB |
| Requires iOS | **12.1** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Metra Electronics Corp.](https://appshunter.io/developer/1133973919) | [AUTHOR-ALARM](https://appshunter.io/developer/1344731145) |

## 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


### Author BT Update

[App page](https://appshunter.io/ios/app/author-bt-update/id6475983875)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is AX free?

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

### Is Author BT Update free?

Author BT Update is free to download, with no in-app purchases.

### Do AX or Author BT Update have ads?

Neither AX nor Author BT Update shows ads.

### Which is updated more often, AX or Author BT Update?

AX ships an update every 2 months, and Author BT Update monthly. Most recently, AX was updated on October 3, 2026 and Author BT Update on October 10, 2026.

---

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