Having an issue with the 777 sound. Very bizarre to say the least. I have 5.1 surround sound set up. When I fly the NGX, I get all engine sounds coming through all speakers whether I am online via FSINN or not. Engine sounds come through all the time through all the speakers.

 

However with the 777 after I start the engines, the engine noise sounds fail to come through the rear two speakers. I have to go into the FSX menu/sound and then select my primary speakers from the menu pull down which are the default speakers (I have a USB headset for online stuff so that is listed as well) to get the engine noise sounds to be heard through the rear speakers. As soon as I do this the engine sounds come alive. But, as soon as I connect to Vatsim via FSINN, the sound for the engines cut out in the two rear speakers. Other sounds continue to play like the rattling sound when taxing, RAAS, etc... Just the engine sounds. I can reproduce this every single time without fail. I can then disconnect from Vatsim but still keep FSINN running and go back into the FSX menu for sound and re-select the primary speakers again and the engine sounds will come back alive again in the rear speakers and stay that way until I reconnect to Vatsim.

 

So to summarize:

 

-On initial load of the 777 which I have as the "short" turn panel state, after starting engines, the sound for the engines will not come out of the rear speakers until going into the FSX sound menu and re-selecting the primary speakers. The sound then works.

 

-After doing the above, once I connect to Vatsim via FSINN, the sound for the engines will stop working out of the rear speakers only. I can still hear rattling sounds and RAAS out of the rear speakers. If I disconnect from Vatsim and go back into FSX sound menu and again re-select the primary speakers, the sound for the engines will come back on. If I stay connected to Vatsim and try to go back in and re-select the primary speakers, the engine sounds will come back on but cut off within a few seconds.

 

-This does not happen with the NGX.

 

Anyone else seeing this? Going to submit a ticket on it.

 

http://forum.avsim.net/topic/420152-how-the-sound-has-been-done-for-the-t7/

 

In post #5 is about your issue. Hovewer, you will have option to play sounds through rear speakers

The thread that Zeljko provided you includes good info from PMDG. Also, verify that your correct sound is selected in the pmdg options sound menu using the CDU.