Jun 10, 2019
Thank you for your post and welcome to the Bose Community.
It great to hear that you are interested in our QC35 II Wireless Headphones.
That is correct. To completely stop Bluetooth, the audio cable will override and disable Bluetooth and BLE.
Here is a previous thread that discusses the same topic which you may find useful: Bluetooth completely OFF on QC35
Please let me know if you have any other queries or questions and I will be more than happy to help.
Charlotte G - Community Support
Jun 15, 2018
You can go to the Apple or Google store and get a free app which checks for Bluetooth Low Energy (BLE). I use "BLE Scanner" on my iPhone. With that you can measure whether a BT signal is coming from the device. The last time I checked my QC35ii, in the OFF position, there was no BLE signal detected. So imho, there is nothing BT related coming from the device when it is off. The same can not be true for all Bose BT devices. For example, the Revolve will put out a BLE signal when it is turned off the normal way. To turn it completely off, you need to hold down the multifunction key for 10+ seconds.