I have a Lenovo T450 laptop with which I'm struggling to isolate 5.1 & 7.1 audio output problems over the DisplayPort. I have a home theater bluray disc player which supports 5.1/7.1 audio, and so does my receiver as the test tones it generates properly route to the 7.1 channel speaker setup I have. So I know the HDMI cable and the receiver are not the issue. I disconnect the HDMI cable from the bluray player, and connected it via a mini DisplayPort adapter to the Mini DP port on my laptop. I've also tried a different brand of mini DP adapter.
The Win10 build 1607 Sound control panel applet detects the HD Audio DisplayPort connection and allows me to select Stereo, 3-Channel, Quadraphonic, 5.1 Channel, 5.1 Channel, or 7.1 Channel. Yes, there are two 5.1's listed... one shows side surround speakers and the other shows rear surround speakers. When I select 7.1, the control panel shows that it's attempting to send audio to all the speakers, but the sounds only comes out of the front left and front right speakers. When I choose one of the 5.1 selections, the test tones come out correctly from the L, C, R, and Sub channels... but for the rear speakers the test tones either only come out the side surround (even when I choose the option where it shows rear speakers instead of side speakers), or the the tones come out both speakers simultaneously (left side surround and left rear surround, for example).
I'm asking here because I've read that the HD Audio is actually integrated the the Intel HD Graphics. The CPU in this T450 is a i5-5300U, and I've read that this CPU includes the HD 5500 GraphicsI don't know if the concern is related to the Realtek system & drivers, or the Intel DisplayPort drivers, or a combination, or something else entirely. Does this hardware support discrete 5.1 & 7.1 audio? If yes, what is causing this issue? If not, why is it allowing me to pick options which are not supported by the hardware? I'm completely up-to-date on all Lenovo driver updates and Windows Updates, except for a Intel Win Mgmt Engine update. That update was previously installed but was rolled back with Microsoft's feedback.
Processor: Intel Core i5-5300U Processor(Core i5-5300U): : Memory: 4GB DDR3L 1600: : Operating System: Windows 7 Professional 64 preinstalled through downgrade rights in Windows 8.1 Pro 64(EN:English): : Hard Drive: 500GB 7200; 16GB: : Wireless Network: Bluetooth Version 4.0; Intel Wireless 7265AC(2x2)+BT4.0 M.2 Combo: : Ports: Ethernet; 3 USB 3.0; Microphone/Headphone Jacks; VGA out: : Camera: 720p HD Camera: : Monitor: 14.0 HD+: : Included Warranty: 3 Year Depot
You may find additional detail in the following posts I've already made that I've unintentionally forgot to include here. Microsoft replied to me at this link indicating the driver doesn't support the desired feature due to the feature score within the driver rank:
Trying the Lenovo support forum but no feedback yet:
Thank you for any guidance you have to offer.