6-Channel Update Guide

🔧 HD-A2B Software Update Guide – SeirenHD A2B Interface

This is for the 6-Channel Model Only! Do Not Attempt to Update the 8-Channel Model with this Guide

Keeping your SeirenHD A2B interface up to date is essential for proper operation, sound quality, and long-term reliability. This guide will help you determine which update method(s) you need to use—whether it’s the 12-18-24 Updater, the DFU website, or the USB radio update method.

Before moving to the sections below, we recommend reviewing the SeirenHD A2B Setup Guide to get the best sound from your system!

*IMPORTANT BROWSER NOTICE*

At this time, Google Chrome and Microsoft Edge may block USB communication with the SeirenHD DFU and EQ websites because the browser reports the site as “Not Secure.”

This issue has already been reported to both Google and Microsoft and is currently being worked on.

Recommended Browser

Use Mozilla Firefox.

Firefox currently allows proper USB communication with the interface without requiring any browser changes or exemptions.

Chrome / Edge Temporary Workaround

If you prefer to use Google Chrome or Microsoft Edge, you can manually add a browser exception to allow communication with the SeirenHD interface until the browser issue is resolved.

Step 1: Enter the following URL into your browser address bar:

chrome://flags/#unsafely-treat-insecure-origin-as-secure

Step 2: Enable the option located at the top of the page.

Step 3: Add the following URLs into the provided text box:

ws://10.10.254.1,http://eq.seirenhd.com,http://dfu.seirenhd.com

Step 4: Click the "Relaunch" button at the bottom of the page to restart the browser and apply the changes.

This browser communication issue has already been reported to both Google Chrome and Microsoft Edge. Until the issue is corrected by the browser developers, this workaround should resolve connection issues when using those browsers.

🔍 Pre-Check: Check Your Current Firmware Version (Inside the Radio)

Before you begin any update, you need to check which firmware version your SeirenHD A2B module is currently running.

Go to Settings
Select Audio
Tap Speaker Setup
Tap “More Info” on the first page
Your current firmware version and date will be displayed

What Your Version Means:

If your firmware is dated 12-18-2024 or earlier:

You must remove the A2B module from the bike
Connect it to a computer
Complete Step 1 and Step 2

If your firmware is newer than 12-18-2024 but older than version 1.3.8 (Feb 2025):

Still remove the A2B module
Connect to a computer and complete Step 2

✅ If your firmware is 1.3.8 or newer:

You can skip Steps 1 and 2
Proceed directly to Step 3 (USB update)

💡 Checking your firmware version first ensures you take only the necessary steps—saving time and effort.

✅ Step 1: Use the 12-18-24 Updater (if software is dated 12-18-24 or earlier)

This step prepares your module for DFU updates.

⚠️ The DFU website will not function until this update is completed.

You must run this update if:

Your A2B module has never been updated
Your firmware is 12-18-2024 or earlier
The DFU site says “Fully Up to Date” but shows no options

⬇️ Download the 12-18-2024 Update (Dropbox)

🌐 Step 2: Use the DFU Website (Only if you’re pre-Feb 2025)

(Requires USB-C connection to PC)

Visit dfu.seirenhd.com after Step 1 is complete.

⚠️ Skipping Step 1 will cause DFU site to show no options.

Firmware Selection:

Using Hertz speakers? → Choose “Hertz”
Velocity speakers? → Choose “Velocity”
Custom DSP tune? → Choose “A2BEQ”

✅ Step 3: Use the USB Radio Update (If you’re on 1.3.8 or newer)

Download correct file to USB
Insert into Skyline OS factory USB port
Turn ignition to accessory mode
Follow prompts
Remove USB after update completes

USB Update Files:

🎛️ Unlock Full DSP Control with A2BEQ

If you've installed the A2BEQ firmware, visit eq.seirenhd.com to customize your DSP settings.

Adjust EQ, crossovers, gain, time alignment
Start with a base tune and tweak from there

Base Tunes: