Magnepan vs B&W: Same specs, different bass?


Hey everyone,

I recently acquired a set of Magnepan 3.7 speakers which are rated down to 35 Hz, and I've been comparing them to my B&W 803S speakers (also rated to 35 Hz).  While I enjoy the big sound and clarity of the Magnepans, the B&W's blow the Magnepans away in the bass department in an A-B comparison test.

I figured this would be the case, but I can't explain why there's such a big difference in bass when the speakers have the same specs.  Can anyone explain?

B&W 803S specs:
35Hz – 22kHz ±3dB

Magnepan 3.7 specs:
35Hz- 40 kHz

Thanks,
Chris
128x128cjwessing
Those speakers seem awfully close to the walls, in my opinion.
Is there any way to move the chair backwards?
B
I agree with gdnrbob.

They definitely should come out from the from wall more. They should be out about 40% of the length of your room and about 6-9 inches from you side wall. 

Cheers 
I just followed the setup instructions from the Cardas website, here are my room measurements:
http://www.socalhifi.com/Magnepan_Room_Setup.jpg

Here's the Maggie's in their 'optimal' position, something tells me my wife won't allow this... =)
http://socalhifi.com/Maggie_vs_B&W_3.JPG

Here's the B&W's in a similar position:
http://socalhifi.com/Maggie_vs_B&W_4.JPG

Here's the measurement comparison:
http://www.socalhifi.com/Maggie_3.7_vs_803S_take2.png

Looks like moving the Maggie's definitely helped in the 40-80 Hz range, but now I've got a significant room mode around 100 Hz.  Also they still don't have the low end punch of the B&W's, maybe it's that sub-40 Hz performance of the B&W that I'm feeling?
They’re way too close together and did you move them out 40 percent of the overall length of your room?
Moved them out 40% of the room width per the instruction, seems crazy to me that these speakers need to basically be in the middle of the room to sound good?