Bass only when I stand up…

@johnread57, very glad you got this worked out!

Enjoy!

Those that suggest it's speaker position are correct.  It's a common problem when the speakers and listening position are both 1/3 into the room.  

I suggest researching Dave Wilson's process of positioning speakers and listening positions.  It will also help you brush up on your public speaking skills.  

consider a ’swarm’. i’ve been in a 12’ x 12’ x 8’ very small room with great bass. when you look at the room no way it should work, but it does.

not cheap, cheap, but not crazy spendy either. cheaper than trying to build another room or find another house. and......drum roll please.....it actually works.

http://www.audiokinesis.com/the-swarm-subwoofer-system-1.html

I am _NOT_ suggesting the OP go this route, especially now that the issue has been solved, but the basic problem is one that lends itself well to satellites with subs. 

If you _must_ place the speakers in a sub-optimal location for the bass then maybe even just 1 sub while high passing the main speakers can work supremely better, assuming you have better luck with the sub locations.

What are you sitting on when listening? I ask this because I had a lack of bass and a thin midrange until I got rid of an overstuffed sofa w/attached chaise and replaced it with some Barcelona replica chairs. 

It seems the sofa was sucking the life out of my system.

All the best,
Nonoise