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For those who want true 5.1 Dolby Digital and DTS

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  • For those who want true 5.1 Dolby Digital and DTS

    I wanted to try to contribute an all in one thread that explains how I was able to achieve Dolby Digital, DTS and Pro Logic from my computer in my car. I hope this helps someone and gives people ideas and saves countless hours of product sourcing.

    This is my hardware:
    Lilliput 7" VGA
    512mb RAM
    VIA EPIA M10000 link
    Opus 90w PSU
    80g WD SE
    40g laptop drive
    Slimline Slot Load CDRW/DVD link Slimline to USB 2.0 bridge link
    Panasonic CY-AC300EX Digital Surround Processor link

    To achieve 5.1 Dolby Digital and DTS you have two roads to take. You can either get an external processor and use your onboard soundcard (if your motherboard offers S/PDIF out like the Via M10000) or you can get an external soundcard that has 5.1 out and Dolby digital. There are pro's and cons to both. Below they are listed

    External DSP Pro's
    1. You can achieve Dolby Digital, DTS over Six chanels (5.1)
    2. You usually have a controll unit (Head Unit) for external volume control
    3. This is really the only option if you want DTS processing
    4. No extra load on your CPU
    5. No USB bandwidth monopolization
    6. Allows the opportunity to have a nearly digital system with the addition of a digital amp.

    External DSP Cons
    1. Usually Expensive. I paid 330 for mine but they can be bought refurbished for less.
    2. You have to control the volume (if using the optical input) with an external control unit which may be undesirable if you want to control the gain on the digital output

    USB Sound Card Pro's
    1. Cheap
    2. Less complicated and less wiring
    3. Control 5.1 Dolby gain with computer

    USB Sound Card Cons
    1. Utilizes CPU to process and decode the surround sound
    2. Utilizes USB bandwidth which can produce choppy DVD playback if you have other heavyweight USB accessories
    3. No DTS processing

    You can see why I chose to go with the external surround sound processor. I wanted True 5.1 and with my hardware I didnít want to intrude on my USB bandwidth and CPU power. This may be of no concern if you have a PIIII and are using a FireWire or IDE DVD drive however even in that case you still donít get DTS processing. If you are on a tight budget and donít care about DTS processing and are using some hardcore hardware then by all means go for the Audigy or Extigy by Creative. Otherwise the external Digital Surround Processor is the way to go.

    The Configuration:
    My Onboard soundcard had a Coax S/PDIF output and the CY-AC300EX had an Optical S/PDIF Toslink input so a converter had to be installed. I used this one: So I ran the Digital out from the computer into the Digital in into the DSP. From there the DSP decoded the dolby codec and split the signal into 6 speretate channels. Each channel needs to be amplified except the center channel (on this particular DSP it has a built in amplifier for the center channel only) so from the DSP I ran each channel to an amplifier. I used a 4 channel 400w amp for the Front and Back Left and Right speakers. The center channel is already amplified (30w) and I ran the Rear channel to a separate mono amp. Check out the attached picture for a diagram

    I used a Monster Coax Digital Cable link and a Phenoex Gold Toslink cable link for all of my cabeling.

    Software Setup:
    I followed this guide for the EPIA I think the process should be similar for any other motherboard or sound card that has S/PDIF out. Use this as only a guide if you have another motherboard. The main thing i think is to find and enable your digital output (coax/optical/ttl) and install the AC3 Codec.

    After you install the AC3 Codec and set it up as it says to in the guide then make sure that your DVD player is set up to output Dolby Digital over S/PDIF. I used WinDVD and was supprised after i had everything setup that i wasn't getting Dolby Digital. I found out after some tweaking that there is a settings page that had the audio set to ANALOG. After I switched it to Digital everything worked fine.

    After you follow all of the above decisions and steps you should be good to go.

    A Couple things to Note:
    Not all DSPís are created equal. Keep in mind when purchasing your DSP that the Mass majority have Proprietary optical cables and Proprietary protocols making it impossible to hook up to the computer. They are mainly made so you buy the complete system from them. I bought the Pioneer DSP and later realized that it A) needs a control unit and canít act as a standalone unit and B) the optical input was proprietary.

    What you are looking for is TOSLINK Optical input that support S/PDIF which the CY-AC300 does. I hear that the Alpine PXA-H510 works for this as well but I have not tested it.
    Attached Files
    -Jesus- King of Kings Lord of Lords

  • #2
    Whoa mamma!!

    Great read. THX!!!

    Now if we can get people to search for it...
    Aura MR62 (F and R)
    My Current MP3s


    • #3
      Good Stuff Anti! got some useful info out of this!


      • #4
        first nice post may I use it on my how to site for auto pc's that I am working on ?

        second the alpine don't work you need an analog signal with the toslink at the same time to controll the volume

        also this statement about the pioneer (the optical input was proprietary) is not accurate the cable is proprietary not the input witch is spdif on the pioneer same as any other dolby 5.1 dsp


        • #5

          Thanks for the clarification on the Pioneer Protocol. I wish you were here earlier when i was looking into buying one. I was banging my head against the wall trying to find answers.

          Feel free to use my any information that you feel has been helpful in what ever way you like...thats why i posted.

          Check your PM
          -Jesus- King of Kings Lord of Lords


          • #6
            Any more suggestion for DSP's with Spdif input?

            The more suggestion the more chance of picking one up 2nd hand!
            Proper Planning Prevents Poor Performance


            • #7
              yah I am an expert installer and know mobile 5.1 dsp's better than most people in the industry and I did tell you about AC3Filter and that it needs to be installed and setup right for dts and dolby remember any way I am going to write a new thread about witch dsp's work with computers and why


              • #8
                ok i have searched but not found a right answer.
                heres my q.
                i am going with out a head unit, and want 4.1or 5.1 but still want to use the mic in for my t616 with the phone software. so with this can i still use the mic in from the regular 3 prong plug?? oh and where can i get one for less then 330, i checked ebay and none showed just the older versions. with out the ex
                Best Technique In Life Is Having No Technique



                • #9
                  As far as i know you can still use the Mic input. The only thing that is digital is the output. I could be wrong as i havn't tried it yet. I will be trying it shortly becasue i am hooking up my USB Radio to the Mic In.

                  ebay link

                  Refurbished link

                  Come on you can search better than that.

                  BTW the ebay link is the same seller that I bought mine from. He is a cool guy. He only lived 1/2 hour away from me so we met half way. Grab em while you can

                  Good luck
                  -Jesus- King of Kings Lord of Lords


                  • #10
                    thats the same ebay link i found but its not a ex whats the diff??? if any i was going to bid on it if u tell me its the same. be nice to have a working system again
                    Best Technique In Life Is Having No Technique



                    • #11
                      It is the same. look on the says CY-AC300EX on the box.

                      He fails to mention that in the auction though.

                      I say bid on it
                      -Jesus- King of Kings Lord of Lords


                      • #12
                        hey antimatter have u tryed the mic yet? and if so how did it work?
                        Best Technique In Life Is Having No Technique



                        • #13
                          Okay, I have a dumb question on this subject.

                          What's wrong with just installing an SBLive PCI card that's got the 3 jacks for 6 channel output? You can then just change the headphone outputs to RCA, then to the amp(s). Would this work? Is it only because most of the carPC's don't have room for a PCI card? Or is there a big difference between 5.1 and Dolby Digital and DTS?

                          Excuse the basic questions, the different sound formats are still a bit confusing.


                          How Much Horsepower Can I have And Still Go To Heaven?


                          • #14
                            Im with superduck... What exactly is the difference? and would it be noticedable when in a car and speakers are not perfectly positioned for dolby (no center speaker, oddly placed front and rear).

                            Also I thought that buying an audigy2 PCI card with a digital out would be more than enough for dolby 5.1?
                            Isnt there an adapter that can splice the single digital out into 6 RCA outs?

                            Thanks for your time in advance...


                            • #15
                              I would have thought an audigy2 would be compatible with DTS...