Take the 2-minute tour ×
Sound Design Stack Exchange is a question and answer site for sound engineers, producers, editors, and enthusiasts. It's 100% free, no registration required.

I'm trying to understand something and I think it's a terminology issue that is confusing the issue for me.

I have a computer motherboard with both an optical SPDIF connector as well as 6 ports for audio output. The motherboard is an ASUS Sabertooth X58. Here is a photo of the ports:

enter image description here

The 6 connectors shown (Orange, black, grey, blue, green, pink) allow me to connect up a 7.1 speaker system. My first question is,

  1. are these ports analog or digital?

  2. Should I be looking at a surround sound system that accepts SPDIF or are the 6 ports digital and immune to noise like the SPDIF connector and therefore no sound quality difference should be expected? Or if the 6 ports are analog but SPDIF does not support 7.1 audio, am I stuck with analog only or can a combination of the two be used like stereo SPDIF for head phone use and analog for surround sound in movie watching?

  3. If the 6 ports are analog, then how is it some of them can carry more than two signals? My assumption up to this point is each port is a two signals + ground.

  4. Does SPDIF carry all 7.1 channels?

  5. I would like to purchase a decent surround sound system to connect to this. I intend to play games as well as watch blue ray movies. Any recommendations for a decent setup?

Here is a what the user manual shows:

enter image description here

share|improve this question

migrated from avp.stackexchange.com Jan 25 at 9:36

This question came from our site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation.

    
While I do like your post, with the pictures and all, and have answered it. It's definitely not about "audio recording and production" (at least not how we intended "production" to be read). This is probably not the best site for this question. –  Ian C. Feb 28 '11 at 14:34
    
It should be migrated to superuser.com, I think. –  Lennart Regebro Feb 28 '11 at 19:21

1 Answer 1

up vote 2 down vote accepted

are these ports analog or digital?

Analog.

Should I be looking at a surround sound system that accepts SPDIF or are the 6 ports digital and immune to noise like the SPDIF connector and therefore no sound quality difference should be expected?

I would personally prefer a S/PDIF connection. One cable is easier to run than many cables. I don't usually use the terms "sound quality" and "on-board audio" in the same sentence. :) I don't think you'll notice much of a difference between the two connection methods and if you did I doubt the problem would be interference over the wire run. More likely it'll come from poor D/A converters in the on-board card -- something you'd be bypassing if you used S/PDIF; in that case you'd be using a D/A in the speaker system.

Or if the 6 ports are analog but SPDIF does not support 7.1 audio, am I stuck with analog only or can a combination of the two be used like stereo SPDIF for head phone use and analog for surround sound in movie watching?

If the S/PDIF connection is stereo-only you're stuck using the analog outputs for a 7.1 speaker setup. You can use both S/PDIF and the analog outputs at the same time on most audio interfaces. I have no reason to doubt this isn't true in your case, but check the manual for the concise answer here. The tricky part of your request would be finding headphones with in-build DA that'll accept a digital signal over S/PDIF. That sounds like a rare product to me.

If the 6 ports are analog, then how is it some of them can carry more than two signals? My assumption up to this point is each port is a two signals + ground

They are TRS connections. They can carry two signals and a common ground wire is shared between them.

Does SPDIF carry all 7.1 channels?

Yes, S/PDIF can carry DTS or Dolby Digital encoded audio signals. Your sound card has to support outputting these encoded audio signals on its S/PDIF connection, obviously.

I would like to purchase a decent surround sound system to connect to this. I intend to play games as well as watch blue ray movies. Any recommendations for a decent setup?

Shopping questions aren't encouraged on SE sites. Maybe ask a new question on how to assess and purchase a good surround sound system for a computer? Though, honestly, this is skirting the mandate of the site.

share|improve this answer
    
I don't rate commenting yet, so consider this as a comment on IAN C.'s thread: Unless your board manufacturer paid the licensing fee for the codec, then SPDIF OUT is most likely restricted to 2 channel output. It WILL pass-through pre-encoded 5.1 such as that found on a movie DVD, but you will not (for instance) get surround-sound from games. –  horatio Mar 1 '11 at 17:41
    
Thanks, I did not know that and will check into it. –  Eric M Mar 4 '11 at 13:53
    
Very informative. From your reply and further reading, I've come to learn & understand that SPDIF is merely an encapsulation technology and not an audio format per-say. I now understand that SPDIF will pass audio in the format given to it. I'm curious though, if SPDIF is merely a pass through and all you have is an analog source, would you first have to find a way to convert it to digital? SPDIF being a digital format; thus requiring analog to be A/D first? In other words, SPDIF does not have an A/D audio conversion spec, correct? –  Eric M Mar 4 '11 at 13:57
    
" check the manual for the concise answer here." Oh, I've poured over the manual and, unfortunately, these details are not spelled out and seem hard to come by. They mention the chipset so I've been reading up on the chipset but, of course, chipset is not the same as the actual "implementation" –  Eric M Mar 4 '11 at 13:58
    
@horatio: which codec may use the manufacturer? Is it possible to encode the surround sound from an application (like a game) to DTS/Dolby/etc, in order for the home cinema to understand it? –  Jesus Cuenca Mar 11 '11 at 13:20

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.