Hey guys I'm wondering if my subwoofer location is any good. most people put it up front. I have cement floor and my sub is in a 2 concrete walls corner blasting towards my sofa (use as a kind of shaker too) I am no audio expert but it feel alright for me. Why does audio experts always put the sub close to the and obviously far from the couch???

tiger, I'll give my opinion but it doesn't mean it's the only way to do it. I like my bass originating from areas close to my main front speakers. It keeps things time-aligned not just in the listening sweet-spot, but everywhere in the room. It also makes sure there is no sense of the bass coming from a different place than the rest of the sound no matter what your crossover is set at. What you might give up in the process is some of the impact that near placement can give you. If you have enough headroom, you are not giving up much in the impact territory.

But isn't bass sounds supposedly undirectional?

That term would be omnidirectional. Bass is mostly omnidirectional, but not entirely. It becomes more directional as the frequency goes up. Many folks also report a sense of pressure that they can feel from the direction from where the bass is coming from. I would not consider the sense of bass to be 100% omnidirectional.

I'm not just talking about direction here, though. I'm also talking about smearing of the sound in the time-domain. That in itself can be a very lengthy discussion.

I am an audio noob in the same boat here. Just purchased a Yamaha YST-SW216BL sub and am trying to locate a good position for it. My room is a family room connected to a kitchen, so basically one long room (family room 12' x 15' attached kitchen 15'x15')
http://theregalbeagle.tv/pics/subhelp1.jpg
http://theregalbeagle.tv/pics/subhelp2.jpg
http://theregalbeagle.tv/pics/subhelp3.jpg
sub spec:

a* High 100W dynamic power
* 10 long-stroke cone driver with magnetic shielding
* Front-firing active woofer
* Selectable high-cut filter
* 25-180Hz low frequency response
# Power rating: 100 watts
# Frequency response: 25Hz-180Hz; -10 dB
# Driver: 10" Long Stroke Cone
# Connectors: 3-way posts
# Magnetically shielded: Yes
# High cut filter: 40 - 140 Hz
# Auto standby: Yes

Thanks in advance

I'd start by trying the corner to the right of your equipment and then make adjustments from that point.

Should I not put anything in front of it? I usually have my shelving unit with wheels (middle pic) in that corner and I can fit the sub behind it.

That can go in front of the sub as long as you leave a couple of inches clearance.