After that the ceiling comes next.
Downward firing sub carpet.
I have a downword firing 12 inch ksw klipsch sub i now wish i had been smarter and done my homework and bought a better sub for the price anyway on the klipsch forums several posters suggested that if you have carpet like i do to put a large ceramic tile underneath the sub.
The higher order harmonics when radiating direct were definitely localizing lower mid bass notes and distorting the sound stage probably due to the.
The domino effect starts because of the shaking of the subwoofer box.
The advantages i saw to down firing was getting the woofer away from my ear the cone was about 15 away when it was direct firing.
Although carpet will absorb some of the sound it is better to place the down fire on carpet than it is on hard smooth surfaces as these will reflect sound directly and cause a boomy listening experience that can be fairly unpleasant.
Since the subwoofer is there to push deeper sounds and longer wavelengths the sound waves it s producing simply won t be affected as much as shorter wavelength sounds like those produced at the rest of the speakers in.
A down firing subwoofer box produces a domino effect if placed inside a room.
Most down firing subwoofers are placed on softer surfaces such as carpet.
Main theater and living room but mine have a surface which is part of the sub itself example psw1200 has a down firing power port that fires to a base surface inwhich the sub.
And even for a down facing subwoofer the amount of sound being absorbed by the carpet is likely going to be negligible.
On surfaces got me thinking at one time also.