Gigabyte GA-K8VM800M woes

J

jetgraphics

Bought a Gigabyte GA-K8VM800M based on the specs claiming 5.1 audio. Of
course, it cost an extra $20 to get the S/PDIF bracket (getting that
was a whole 'nother tale of woe). However, when all was properly
connected, NO 5.1 audio. The digital signal (on COAX) consisted of L &
R signals only.

Ran the set up utilities, etc, etc.
Ran the speaker placement test.
L, R = good.
Sub, C, Lr, Rr = silence.

Tested the receiver's digital inputs with separate digital source, ran
THX audio test, also verified 5.1 speaker connection with test tone.
Good receiver. Good speakers.

No reply from Gigabyte, yet.
 
P

Paul

Bought a Gigabyte GA-K8VM800M based on the specs claiming 5.1 audio. Of
course, it cost an extra $20 to get the S/PDIF bracket (getting that
was a whole 'nother tale of woe). However, when all was properly
connected, NO 5.1 audio. The digital signal (on COAX) consisted of L &
R signals only.

Ran the set up utilities, etc, etc.
Ran the speaker placement test.
L, R = good.
Sub, C, Lr, Rr = silence.

Tested the receiver's digital inputs with separate digital source, ran
THX audio test, also verified 5.1 speaker connection with test tone.
Good receiver. Good speakers.

No reply from Gigabyte, yet.

All that is missing, is a DVD movie, a software program to play the
movie, and setting it for AC3 passthru. 5.1 only works "for free", with
an AC3 encoded stream. SPDIF is inherently stereo - there are just two
channels. AC3 is a coding scheme, that compresses six channels of
information, into the space of two channels. Your receiver has the
decoder inside it, to take apart the compressed stream, and reconstitute
the original information. A light on the front of the receiver
lights up, when an AC3 stream is detected.

There are software encoders, that can take 5.1 "analog" info, and
compress the data on the fly, to make the necessary AC3. Strictly
speaking, a licensing fee needs to be paid to Dolby Labs, if
some software does that. The encoder has a delay (latency) of 0.5
seconds, which can ruin lip sync.

The Nvidia Nforce2 chipset MCP-T Southbridge, has a group of
DSP blocks, that can make AC3 on the fly as well. The latency
on Nforce2 is much better.

I believe there was also a $100 sound card from a Korean
company, whose main purpose was running SPDIF in 5.1 all
the time. Presumably that had some hardware on the card,
to make the necessary AC3.

But for free, the easiest way to test that it is working,
is to get a DVD movie, a good DVD player application, and
set it up for AC3 passthru. The necessary AC3 is already
recorded on the DVD and you've already "paid for it".

Paul
 
K

kony

Bought a Gigabyte GA-K8VM800M based on the specs claiming 5.1 audio. Of
course, it cost an extra $20 to get the S/PDIF bracket (getting that
was a whole 'nother tale of woe). However, when all was properly
connected, NO 5.1 audio. The digital signal (on COAX) consisted of L &
R signals only.

Ran the set up utilities, etc, etc.
Ran the speaker placement test.
L, R = good.
Sub, C, Lr, Rr = silence.

Tested the receiver's digital inputs with separate digital source, ran
THX audio test, also verified 5.1 speaker connection with test tone.
Good receiver. Good speakers.

No reply from Gigabyte, yet.

As Paul mentioned, you have to have a 5.1 channel sound
source, _OR_ you might have a setting in your audio card
(driver) software control panel to copy or otherwise
transfer some audio to more than the L & R channels.
 
J

jetgraphics

kony said:
As Paul mentioned, you have to have a 5.1 channel sound
source, _OR_ you might have a setting in your audio card
(driver) software control panel to copy or otherwise
transfer some audio to more than the L & R channels.

Apparently the AC97 audio configuration utility that tests the 6
channels doesn't properly encode the signals. It has a cute graphic
with 6 speakers you can select for testing. However, only left and
right speakers responded. If that utility doesn't generate 5.1 sound,
it's pretty useless as a 6 channel speaker tester.
Go figure.

Good news - I was successful getting a 5.1 signal from PowerDVD.

Thanks for the replies.

Problem resolved.
 
K

kony

Apparently the AC97 audio configuration utility that tests the 6
channels doesn't properly encode the signals.

I should have mentioned that it's not going to encode it,
you'd have analog out for the rest on AC97 if the driver
control panel is fancy enough to support it.
It has a cute graphic
with 6 speakers you can select for testing. However, only left and
right speakers responded. If that utility doesn't generate 5.1 sound,
it's pretty useless as a 6 channel speaker tester.
Go figure.

Plug speakers into your analog output then retry it.

Good news - I was successful getting a 5.1 signal from PowerDVD.

Thanks for the replies.

.... at least it works!
 
B

bomberb17

Can't you get 5.1 sound (or at least 4-speaker sound) from computer
games that support it?
Which are the software encoders that compress "analog" sound
to AC3 sound?
 
R

Raymond Martineau


This is not a web forum. Posting a single line message does not
guarantee other postings will be brought to the front, nor does it
ensure content will be shown - in this case, the posting you are
replying to has been deleted from the news server.

If you intended to self-reply, then yes, 5.1 audio is supported by
some games. If you are looking for an AC3 encoder, you have to search
for one - usually they are commercial grade and not necessarily
freeware.
 

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