Originally Posted by pevsfreedom
Onkyo HT-S3400 5.1-Channel Home Theater System
It's hooked up (audio wise) via the 3.5mm green audio jack which goes to the Onkyo (splits into a RCA and plugs in) which goes directly to the speakers.
So your currently running a 2-channel stereo analog audio signal from the computer to the Onkyo.
(I'm assuming your using the 5.1 speakers that came with your HTiB HT-S3400).
Update the audio software on your computer and make sure the computer's audio is set to 2-channel (not 5.1, 6-channel)
and try doing a reset on your Onkyo.
"To reset the AV receiver to its factory defaults, turn it on and, while holding down VCR/DVR, press
ON/STANDBY. “Clear” will appear on the display and the AV receiver will enter Standby mode.
Note that resetting the AV receiver will delete your radio presets and custom settings."
So you would have to go into the Onkyo's setup and put back any custom settings you had.
Also you could get a S/PDIF optical cable, connect the computer motherboard's optical output to the optical input on the Onkyo.
I'm assuming your motherboard comes with DDL (Dobly Digital Live), which would give you 5.1 speaker surround sound.
As with your current setup (3.5mm grren jack) the best you can do is a fake surround sound (expanded stereo).
If your computer's graphics card has HDMI, you could run HDMI from the graphics card into the Onkyo, then run HDMI from the Onkyo to your TV/Monitor.
Or if you would prefer to use optical and not HDMI and your computer's motherboard did not come with DDL, then you could get an Xonar DX or D1 sound card (used $60) as it comes with DDL (and Dolby Headphone surround sound, if you used headphones plugged into the Onkyo)