I'm putting in a 3.1 system (Artison speaker bar and in-wall sub) and wondering if I'm going to lose any audio by not putting in surround speakers, besides the obvious surround sounds. I'd guess I'll still be getting all three front audio channels.
If I'll lose anything I can put AVR in stereo mode and not use center channel, I guess.

For Ernie, system components:
Marantz NR1403
Sony 65" XBR HX950
Artison LCR speaker bar
RBH In-wall subwoofer, SA200 amplifier

Apple TV
Directv DVR
Sony Blu-ray
Some Karaoke DVD player

Not for me, for you. Try working out an exact answer for yourself without that info -- there might be equipment details that color the entire reply.

The theoretical answer is that you won't lose a single thing unless you can somehow set this up as 5.1 or 42.1 or anything in between, but then you only connect the 3.1 speakers. See, then some of the audio would be removed from the 3.1 and sent to speakers that aren't there. All the audio will go to the 3.1.

However, that occasional single cricket or that minor dog bark that would have come from one and only one of the rear speakers will come from one of the front speakers. You don't lose ANY sound by setting up 3.1. You lose the added specific positioning of sounds that you can get with rear speakers. You don't even lose anything with mono.

set up the AVR as only having 3 front speakers and a sub, and it will steer all the sound to those speakers appropriately.

It will be fine. No loss of anything formats or anything critical. Just loosing the rear effects.

Would the client appreciate the rears? How much would it cost the client to add, wireless or wired?

Bingo. Until last week I had a 3.1 setup at home. I was messing around with some settings and accidentally turned on the surround outputs. Then later I was playing COD and I noticed if I turned while someone was speaking to me I couldn't hear them anymore. At all. WTF? Oh my Surrounds must be set to on! Went in, turned them back off, BAM - the 'rear' voices coming out of the left and/or right spks.

Then I installed surrounds. lol.

"Then later I was playing COD and I noticed if I turned while someone was speaking to me I couldn't hear them anymore."

I cannot make sense of this.

That's what I figured, but wanted to check anyways, thanks for the feedback.

He turned, and UPS was at his door with a package, requesting money.

Noob

I take it its a scene from a movie called COD. ?

you make me sad :(

Call of Duty....its a video game.

that explains why I didnt know it, im not a gamer, lol.

However, the statement still makes no sense to me, turning head, cant hear? still at a lose. But im letting it go, lol.

Let me guess. He does not mean HE turns his head, but rather he makes his game avatar turn its head. When the avatar is talking to someone behind him, the avatar of another gamer, located behind him in the game, responds. From behind. Because there are no rear speakers, no sound is heard.

I don't care how cool it is to assume that the entire world plays video games, not giving the actual title is sad. It's even sadder if I'm right and he is talking about his avatar but identifying it as himself. Dude, it's not you -- it's part of a game.