I have two headphones, both are APT-X Bluetooth. One's a jogging headphone and the other is a Velodyne vFree headset.
My computer is Windows 7 x64.
Prior to installing the CSR APT-X driver, I was using the default Windows Bluetooth drivers. And had acceptable volume levels.
But since the Windows drivers don't support APT-X, I decided to install the only APT-X driver on the market, which is the CSR Bluetooth driver. Driver name is: CSR_Harmony_2.zip
Problem is, while APT-X sounds nice and crystal clear, I no longer have the same volume levels. Now everything is noticeably lower volume and while it's loud enough for casual listening, it's nowhere near loud enough for watching movies.
I've already verified the volume levels for Windows and the Bluetooth drivers are both set to max, as well as my media player.