14 Replies Latest reply on Aug 8, 2017 4:57 PM by Intel Corporation

    Intel Display Audio (Intel HD Graphics 4600) and 5.1 Surround Sound


      I'm using a Toshiba Satellite S55T with onboard IDT sound. However, I'm not using the on board sound. I'm trying to pass audio through HDMI to a Monoprice (https://www.monoprice.com/product?p_id=5557) switch to split the audio signal off. From the Monoprice switch, I send the audio signal via optical cable to a Panlong 5.1 decoder similar to this (https://www.amazon.com/Panlong-Audio-Digital-Decoder-Co...).


      The audio is handled by the laptop by Intel Display Audio (Intel HD Graphics 4600) over the HDMI cable. When I go and configure the Intel Display Audio connection under Sound, I get a choice of stereo, 2.1, 3.1, 5.1, 7.1 speakers. I select 5.1, and start the audio test. Here's where the problem is--I can only hear tones from the front left and front right speakers. The test routine shows that it is trying to send a tone out to the other speakers, but I can't hear anything.


      Switching to my DirecTV service using the Monoprice switch, I get full 5.1 sound. Running a self test on the Panlong decoder shows that all speakers are working properly. But for some reason Windows will not play 5.1. The laptop is properly detecting that the speakers are attached, because I can switch the Monoprice to 2 channel mode and my only speaker selection in Windows shows stereo only. Switch back to 5.1 on the Monoprice, and Win 10 reports that the surround speakers are there. Still only the front left and right speakers work.


      The vexing thing is that this USED TO WORK!!! I noticed, about a week ago when I was encoding a documentary, that I couldn't hear the dialogue, only the ambient noises. I thought I encoded the show improperly because the documentary was originally in French with english as an afterthought, so I did it again. No change.


      I've tried rolling back drivers, going back to the Manufacturer's web site. I've tried older Intel drivers, as well as the newest release. I've unstalled the device and deleted the drivers and then let Windows Redetect and install new drivers.  Nothing seems to work


      I'm assuming that this is a graphics driver problem, since I am trying to use the Intel Display Audio to handle all sound tasks.


      Any ideas?