I think your only solution for getting video and sound output out to 3 HDMI ports Simultaneously is to use a multi HDMI GPU. Mixing DVI etc isn't a good idea in any case.
With a decent GPU both sound and video are routed through each HDMI port --- you also need the software to run these monitors as well --usually you'll get this with the card.
Normally though if you've got 3 monitors on the same desk I assume you only need the sound out of ONE monitor at a time - not simultaneously !!!!!.
The cards are expensive but if this is what you want to do there's no real alternative
This card will give 6 Audio output streams (as well as 6 Video)
6 Monitor Video Card | Multi-Display | 6 Output Graphics Card
Better have a decent size wallet though.
I said these sorts of cards are expensive as they tend to be used for specialized applications. I'm getting one for use in a Stock trading system -- will need some good trades to pay for it !!!!!!!.
I need the graphics to drive several LARGE monitors -- rather like those you see on Bank's Stock trading floor or NASA Control rooms.
These aren't really designed for standard home consumer purposes.
However a Get around for you could be to install TWO cheap graphics cards both with HDMI output - that should fix the sound problem. Not sure how many slots you have on your computer but two half height cheap ones should easily drive what you need. I assume you've already got one Video output already so that makes the 3.
Another option if you don't need all 3 outputs at the same time is to use an HDMI switching box. Manually set to positions A,B,C from one HDMI input.
In case you missed it, the "Surround" in this instance doesn't deal with the sound. It's the NVidia Surround, it treats multiple monitors like they are just one big single monitor. 3 1080p screens look like one 5760 x 1080 screen. When the OP turns that on, he gets a no signal. With it off, the his three screens all work. With it on, your Start Screen etc, would span across all three monitors. Windows just thinks its one big screen. Games will do the same, which is what I think its more meant for, gamming.
the OP's question was confusing (at least it was to me) -- he either wants 3 Monitors from ONE Video card output -- in which case you'll only get ONE sound stream (possibly both analog and digital but the same sound) which would go to whatever the primary monitor is -- or he wants to run 3 Monitors with separate applications on each - a multiple output video card or multiple cards will yield multiple sound streams.
The case of the video card with Single output can produce video from HDMI. DVI and possibly VGA concurrently but there will only be one sound stream as there's only one audio chip in the video hardware. How the video card drives 3 monitors depends on the hardware - the documentation or website should give you the permitted combinations and outputs obtained.
Original Post didn't seem to make this clear.
He did leave some info out initially. If you take the time to read all the posts it becomes obvious what he's trying to do. It has nothing to do with the "sound" output though. NVidia chose a poor name for that feature, IMHO. http://www.geforce.com/whats-new/gui...680-surround#1
What it does is fool Windows into thinking your multiple monitors are just one big monitor. It's great for gaming, if you can get it to work. I have monitors with different resolutions so it will only work on 2 out the 3 I have. My two identical 19 I-Inc monitors.