Pc to a/v receiver only getting 2 channel sound

[specimen34]

wasn't sure if i should post this in the video card section or home audio section so i posted in both. ok so i installed an HIS 5770 video card with hdmi output that puts out up to 7.1 sound. i also just bought a sony STR-DH800 receiver. so here's my set-up, i have a dvi connected from my card to my 19" lcd monitor and that's my primary monitor. i have an hdmi cord going from my card to the receiver and have that be my 2nd monitor(receiver is connected to my 56" samsung 1080p dlp). my tv is working great as a 2nd monitor. the display on the receiver says "linear pcm" which should be correct. i'm getting sound from my receiver, but only through the two fronts. so i went into my sound manager in my control panel and ati hdmi output is checked as the sound device. i went into configuration and stereo was selected so i switched it to 5.1, but i'm still only getting 2 channels. i go back into configuration and "test speakers" and the receiver display shows that it's doing somethung but NONE of the speakers make any noise, but the front two work when i play a file. what the hell is the problem?

 

[astrallite]

Turn off the function where the receiver sends audio to the TV. On some receivers it's called simply "hdmi audio." The video card is reading your TV as the device instead of your receiver. Your receiver should play all the channels afterwards after disabling hdmi audio passthrough.

 

[MEgamer]

isnt it easier jsut to use a power amplifier directly to PC? (just asking)

 

[astrallite]

isnt it easier jsut to use a power amplifier directly to PC? (just asking)

He has a $200 receiver, a multichannel power amp is at least $800. Plus he would need a pre-amp ($300?). Using hdmi also requires less hoop jumping than analog outs when it comes to versatility of outputs.

 

[MEgamer]

i thoguht the outputs on the PC are already pre amped, thus only requiring an amp in an active speakers to increase teh volume.

 

[astrallite]

Go ahead and try it lol.

The output voltage is too low on sound cards. Try taking removing the volume pot in your computer speakers entirely and power the speakers with just your sound card. You might manage 1 to 1.5 W of output attenuating the sound card to the max.

 

[MEgamer]

yes i know,,, this si why u need a power amplifier....

 

[MEgamer]

what im saying is you dont need a pre amp when amplifing sound from the PC< because it is already at line level at teh outputs.

 

[astrallite]

500mV to 1V will not give you any useful power. Consider an amplifier that maxes out at 10 amps. At full blast you will be getting 5 to 10 watts of power during transients. You might get 1-2 watts of power during normal playback. Realistically you need something like 15V.

Take for example, the B&O ASP1000 module, which is capable of handling 35A and 1000W of RMS power. To maximize the volume, you would need an input voltage of 30V.

 

[MEgamer]

oh i see

now i see that u must have a pre amp