Users claim that the ANC is much worse after the official firmware upgrade to 4.1.1. A firmware downgrade is possible to 2.0 by tricking the Sony
Headphone Connect Android application to update the firmware for the headphones from a custom server ran on the local network.
The following zip file:
contains two python scripts:
sony-WH-1000XM3-downgrade-2.0-MDRID291600.py- for international headphones,
sony-WH-1000XM3-downgrade-2.0-MDRID291601.py- for Japan/EU headphones
with instructions at the top on how to downgrade the firmware.
The version of the
Headphones Connect application that was used to perform the downgrades can be downloadeded locally:
The scripts contain a built in HTTP server that Android is made to connect to from the
Headphones Connect application with the proxy settings pointing to the machine running the scripts. Once connected, the scripts will intercept the
Headphones Connect requests to the Sony update server and then upload the payload (the scripts have the 2.0 firmware inside as a Base64 encoded string, hence the size).
The downgrade scripts are attributed to FormalDetail5.