# A540DSP vs PZ

The clearest difference is update cadence: PZ at every 8 days against A540DSP's every 47 months. PZ also leads on iOS requirement (9.0 vs 15.6). A540DSP's advantage is review sentiment (50% vs 29%). On price, ads, in-app purchases and monetization model there is nothing between them.

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

A540DSP ships an update every 47 months, PZ every 8 days. The most recent releases landed on October 25, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | A540DSP | PZ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/pz-c31s/id6741699898/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | **50.0% of reviews** | 28.6% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 47 months | **Every 8 days** |
| Monetization | Free | Free |
| Size | 26 MB | 2 MB |
| Requires iOS | 15.6 | **9.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [杏生 卢](https://appshunter.io/developer/1094592555) | [huizhou shangshui technology co.,ltd](https://appshunter.io/developer/1762340195) |

## What reviewers say

### A540DSP

[App page](https://appshunter.io/ios/app/a540dsp/id1423992250)

Control your car amplifier's audio settings, including EQ, bass, and time alignment, directly from your phone. Save and load custom sound profiles for a personalized listening experience.

**Highlights:** EQ control, Bass adjustment, Time alignment, Phase and mute settings, Filter control, Save sound settings to phone, Save sound settings to amplifier, Load sound settings from phone

**Features:** macOS Compatibility

**In-app purchases:** none


### PZ

[App page](https://appshunter.io/ios/app/pz-c31s/id6741699898)

This app allows for advanced, non-destructive audio modifications in cars using a 6-core DSP chip. It offers precise sound tuning, Bluetooth and USB music playback, and smartphone integration for personalized audio experiences.

**Highlights:** 6-core 32-bit DSP processing, DRC dynamic music processing, Bluetooth and USB music playback, Smartphone sound customization, 31-band EQ tuning, Adjustable sound field delay, Lossless installation

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is A540DSP free?

A540DSP is free to download, with no in-app purchases.

### Is PZ free?

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

### Do A540DSP or PZ have ads?

Neither A540DSP nor PZ shows ads.

### Which is updated more often, A540DSP or PZ?

A540DSP ships an update every 47 months, and PZ every 8 days. Most recently, A540DSP was updated on October 25, 2026 and PZ on October 15, 2026.

---

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