Where to place room treatment?

Hi,
I plan to buy some bass trap, diffusing and absorbing materials for treating my room, and the room is 8Hx10wx22L. Here are the questions
1/ Where to place room treatment, and where should I put diffusing or absorbing materials?
2/ Do I have to buy the ASC tube trap to control down to 50Hz? Are there any things cheaper than ASC?

Last night, I used Audiophiles test CD and Radio Shark analog meter to measure the low requency between 200Hz to 40Hz.

200Hz, 160Hz = around 68 to 69db
125, 100, 80Hz = around 74 to 76db
50, 63Hz = around 82 to 86db
40Hz = 72db
Do I have a peak problem @ 50 and 63Hz? Tube trap help?
How about the low at 200, and 160Hz? How to fix?

Thanks a lot!
Tran