I use my pc to hold movies which I pipe through my projector onto a
screen.  My problem is I want to get the best sound I can and I dont
know a thing about doing it.  I have a audigy 2 sound card..I take a
cord out of that into a rather cheap surround sound system, I plug the
cord into a splitter which goes into two rca jacks and I get the
sound.  I can control the sound both from the pc and from the
amplifyer.  However I do not get any sound on my rear speakers.  I do
get surround sound if I play a dvd on the Phillips sound system but
not when I plug into the sound system with my pc and use my movies
that are on my hard drives. Maybe I dont have the right wires, or the
right sound card.

If you are using two RCA connectors then chances are super high that
the sound you are feeding to your sound system is just plain stereo.
If you want to drive muti-channel sound from the PC to your system,
you need to use the multi-channel digital output on the back of the
card. Some Audigy 2 models have one coax SPDIF output, higher end ones
have both coax and optical SPDIF. If you have only opical input for
digital sound on your sound system, you can buy a 'Digital I/O module'
made by SB to convert - I am sure other vendors have similar hardware.
Of course your content needs to have multi-channel sound. If you
right-click on your video file and select Properties/Summary/Advanced,
you will get some info about the audio. You are looking for AC-3
encoded audio. Alternatively, your audio system may have the
capability of adding surround effects to stereo sound - but there it
is using it's judgement to 'invent' multi-channel sound from stereo;
not too great...

Thank you for you assistance.   My SoundBlaster Live video card has
line out plugs.  The green and black ( I assume their is some sort of
general color code agreement in the trade but that may be too generous
) they say connect to powered speakers or an external amplifier.  A
pink out put is they say an 'Analog/Digital Out connerctor, 6-channel
or compressed AC-3 SPDIF output for connection to external digital
devices or digital speaker systems.
 (What do you mean by "coax SPDIF output?)
Using the simple bin stero plug from radio shack that splits into two
RCA jacks, I plug into the  Green Line out 1 connector and into the
two available RCA in plugs on the back of my Phillips digital surround
system.  I get adaquate sound but not surround sound.
The Black plug from the SoundBlaster I get nothing from when I plug
into that plug...The pink plug, I also get nothing from.  Is it
possible I have the wrong plug so I cannot pick up the signal, or
wrong speakers?
The Creative write up on the pink plug says I can connect a mini-plug
to a DIN  cable and into a digital DIN speaker system  ( Cambridge
Desktop Theater or Creative Inspire 5700 )
The say I can also plug one plug into the pink~hook that to the Analog
 Front, another to the Green ~hook that to the Rear and Center and
third to what they call Subs Inputs...  That is using the same systems
as described above.

Now why should I be confused?

BIG QUESTION: Do I need a separate power amplifier?  Most the movies I
 put on my hard drive have dolby digital, dts or matrix sound so I
assume when I play them back I should be able to get the same.
Do you have any recomendations for equipment that would help me do the
job I want without breaking the bank?

I hope this clerified my prediciment.

Thank You for your time

Jim

Hey there, 
If you could give the exact model of the reciever/surround box that
you are plugging the audio from your SB into, it would probably be
usefull, However with out that, Here is my best guess:
I
 think what you need is a cable that has a stereo plug on one end, and
a single RCA connector on the other end.
The Stereo end goes into your Sound Blaster, into the port they lable
SPDIF, of DIgital, or AC-3.
The other end goes into your reciever, into a single Audio RCA port
in, It is probably black and May say "Digital" or SPDIF.
If you can send exact modle # of reciever and version of Soundblaster
(Audigy 2, Value, Platinum, etc)  or a pictures of the back of each
device to (travisx@gmail.com) I will try to help further.
Travis.