Windows 11 Volume Mixer Not Working Correctly with BlackShark V2 Pro (Original Model)

Update after further troubleshooting:

First, to clarify the hardware: I am using the Razer BlackShark V2 Pro (2020 / original model), not the 2023 model.

Since my original post, I have done much more detailed troubleshooting using PowerShell, PnPUtil, Device Manager, Windows audio settings, and repeated A/B testing.

I also want to mention that I used ChatGPT to help organize the troubleshooting process, interpret the PowerShell/PnPUtil results, and prepare this summary. However, all of the tests and results below were performed and verified on my own PC.

At this point, the issue appears to be very closely related to the THX Audio Effects/APO processing path.

What I tested:

1. I checked the BlackShark V2 Pro device, the installed driver packages, related THX PnP components, and the THX packages stored in the Windows DriverStore.

2. I completely removed the THX-related PnP components and all THX driver packages associated with the headset.

3. After rebooting with the dongle disconnected, I confirmed that no THX driver packages or THX components remained.

4. I then connected the BlackShark V2 Pro again without running Synapse.

In this completely THX-free state, Windows used the Microsoft standard USB Audio driver (wdma_usb.inf).

Result:
Windows per-application volume changes were applied immediately. There was no 0.5–1 second delay.

5. I then installed only the current THX 3.2.3.0 components again.

The BlackShark V2 Pro was then using:

thxusbapo.inf
THX Ltd.
Version 3.2.3.0
Driver date: 06/24/2024

The following current THX components were recreated successfully:

- THX Spatial Audio Effects Component
- THX Spatial Audio Service
- THX Spatial Audio Configuration Razer BlackShark V2 Pro 0528

Only the current THX component lineage was present. Older THX 3.0.36.0 packages/components were not restored.

6. After rebooting, I tested the Windows Volume Mixer again before making any additional changes.

Result:
The 0.5–1 second delay immediately returned.

This happened even with Synapse not actively running.

7. I then tested Windows "Audio Enhancements".

Audio Enhancements ON:
- Synapse EQ / THX processing works
- Windows per-application volume changes take approximately 0.5–1 second before the audible volume actually changes

Audio Enhancements OFF:
- Per-application volume changes are applied immediately
- Synapse EQ / THX no longer works

Important detail:
The Windows volume slider itself moves immediately.

The Windows master volume also reacts immediately.

The delay only affects the actual audible result of per-application/session volume changes in the Windows Volume Mixer.

I also tested Chrome, Edge, Discord, Apple Music and other applications, and the behavior is not limited to one application.

As an additional test, I disabled Windows Audio Enhancements and used FxSound as an alternative EQ.

With FxSound:
- EQ works correctly
- Windows per-application volume changes remain immediate
- The 0.5–1 second delay does not occur

Because of this, it does not appear to be a general problem caused simply by using an EQ.

My current conclusion is that the problem is most likely related to the THX 3.2.3.0 Audio Effects/APO processing path and how it interacts with Windows 11 per-application audio session volume changes.

The strongest A/B result is:

THX completely removed + Microsoft standard USB Audio driver
→ per-application volume is immediate

Clean THX 3.2.3.0 installation + Audio Enhancements ON
→ approximately 0.5–1 second delay

THX 3.2.3.0 + Audio Enhancements OFF
→ per-application volume is immediate, but Synapse EQ/THX is disabled

For now, my workaround is to keep Windows Audio Enhancements disabled and use FxSound instead of Synapse EQ/THX.

If Razer would like to investigate this further, I can also provide the PowerShell/PnPUtil commands used during testing, PnP device information, driver package information, INF details, Windows build information, and additional test results.