Do you know the cheapest way to get full sorround sound.?

Very vague question. If you buy cheap new gear you will get poor quality. Check out systems that cost 2 or 3 times what you can afford. When you have decided which sounds best, try and buy that system secondhand on Ebay/Craigslist/Gumtree. Used, medium quality systems will beat the socks off new, low quality budget systems every time. There are always people who have lots of money & upgrading to a more expensive or newer system, or people who are emigrating/moving house and prefer to replace all their stuff than go through the hassle of moving it.

Check out the Onkyo TX SR 313 receiver and Fluance AVHTB speakers...you can get the Onkyo for about $150 and the Fluance speakers for 250 that's $400 about the cheapest I could recommend....

This is the cheapest I would go, at the moment.

Pioneer VSX-524-K receiver, $197 free shipping ($50 off sale price ends 3-21),

http://www.bhphotovideo.com/c/product/1053122-REG/

Monoprice 10565, Premium 5.1 Home Theater System (with 8" powered subwoofer), $222 free shipping,

http://www.ebay.com/itm/390980031925

Several possibilities including: a used set of computer speakers with digital audio input (e.g. Logitech Z680 or Cambridge Megaworks 501D); a used budget 5.1 "Home Theatre" with an optical input; a set of 5.1 speakers (See for example http://www.cnet.com/topics/speakers/best-speakers/... and a (used) surround receiver (~$100) to drive them. If discrete surround (separate speakers) isn't essential you could consider a powered sound bar with optical input. Just remember you get what you pay for, so don't expect great sound from (most) budget systems.

Cheapest and "full" do not belong in the same sentence, unfortunately. Cheapest would be you and four friends practicing music on kazoos, or with combs and wax paper. heres a link to systems put together at different price points:

http://www.audioholics.com/recommended-systems/100...

To get surround sound you have to have something called a "surround sound processor". Normally you buy something called an "AVR" (Audio Video Receiver) which has the surround sound processor built in along with multiple power amplifier channels etc. Without that surround processor and multiple amplifier channels you simply cannot get surround sound.

There are package systems called HTiB (Home Theater in a Box) that includes some sort of basic AVR and speakers. This is generally the cheapest way but these are problematic. They frequently have few or no aux inputs meaning you may not be able to use them for anything other than playing disc on the built in player. Also generally if any part of the system fails you must throw the entire thing in the garbage as no part of it is compatible with anything other than what it came with. We here on Yahoo Answers regularly have to provide this bad news to people who have already had one of these HTiB systems fail. Too late for them, they already have it, since you do not, you can avoid it by not buying an HTiB.

The better way is to buy components separately. Buy a budget AVR $200 ~ $300 and inexpensive speakers.

Example:

Get one of these... http://www.amazon.com/Denon-AVR-S500BT-Receiver-Ca...

Get two pair of these...http://www.amazon.com/Micca-MB42-Bookshelf-Speaker...

Get one of these... http://www.amazon.com/Micca-MB42-C-Channel-Speaker...

Get one of these... http://www.amazon.com/Polk-Audio-10-Inch-Powered-S...

The above is just an example of some really low cost equipment. There are lots of similar choices. A system in this price range is not going to be very good, not very good at all but if all you are use to is PC speakers you may think it sounds pretty nice. It will give you basic surround sound and it will sound a lot better than the speakers built into a typical TV. If you want better, you have to spend more money. Very high end systems can cost tens of thousands of dollars and more... a lot more!

mk

What exactly is your budget? By the way, optical is not the only connection you can use with the xbox one. Best way is using a receiver with HDMI inputs and output. This is a nice entry level system that would work http://www.amazon.com/Onkyo-HT-S3500-5-1-Channel-T...

Borrow somebody else's....

or maybe you should clue us in on what size budget you are on....because you get what you pay for.