Bass disappears when I sit down

[statikcat]

Hey everyone. Feel free to merge this with another thread if needed.

I have an Acoustic Audio Sub12 and am having a weird issue in my new apt that I did not have in my old apt. When I stand up in my listening position I hear lots of sub.. when I sit down it drops dramatically! I always thought of sub placement as helping on the horizontal axis. Is there anything special you can do to correct verticle issues? I have never had this kind of issue with a sub before.

The sub is about 12-14 inches from the wall and not near any corners. Like a lot of HT the sub is about 8 feet in front of me and to the left about 2 feet. The tv stand is to it's right and floorstanding speaker to it's left. The front positioning is the same as my old apt. It is sitting on carpet and I have been thinking about getting a platform for the sub.

Any suggestions?