Physics of downward firing woofers

Works great with a subwoofer but is totally wrong for proper bass woofer 

How about upward - firing woofer ?

Advantages and did advantages.... Personally, it is rare that a down firing woofer is as accurate as a front firing.  It isn't impossible, but the floor makes an effect on the bass.  The gap between the floor and woofer can act as a slot load to a ported cabinet,  giving a bass increase at given frequencies.  Kinda like adding another port. If the woofer is too close to the floor as the bass rebounds, it can cause some cancellation.... So Getting a down firing right is tougher than a front firing.  Next,  a down firing woofer does offer some cone protection if it were ever needed. Down firing ports are a very different scenario and really are a different conversation,  they are not affected by the same problems of a down firing woofer. 

inna - 

Usually done for omni or semi-omni directional designs, like Linkwitz LX Mini

http://www.linkwitzlab.com/LXmini/Introduction.htm

Floor bounce is the wrong word for bass, but interference is a real thing. Anytime you see a woofer far from the midrange and near the floor you are seeing designers think this is important.   Perhaps this is more related to having an even boundary re-inforcement? 

Best,

E

Downfiring is probably not a very good idea if you have carpeted floor. Unless I am terribly wrong.