Front- and down-firing subwoofers -- Teufel Audio blog
Down Firing vs. Front Firing Subwoofer - Blog - REL
Down Firing VS Front Firing Subwoofers (What REALLY Matters!!) - YouTube
Dayton Audio 6-1/2" Down Firing Active Mini Subwoofer Kit with 2.1 Channel Amplifier 60 Watts
Amazon.com: Creative Pebble Plus 2.1 USB-Powered Desktop Speakers with Powerful Down-Firing Subwoofer and Far-Field Drivers, Up to 8W RMS Total Power for Computer PCs and Laptops (Black) : Electronics
DIY Down Firing Subwoofer Build for 2.1 Home Theatre - D&T#011 - YouTube
Down Firing 12" Subwoofer Box | Speaker Enclosure Good for Underseat or Car Compartment | Very Good Qulity Car Audio Design Speaker Box | Passive Setup Black | Lazada PH
L10cs Classic Series Subwoofer | 10-inch (250mm) Down Firing Powered Subwoofer
Dali Alteco C-1 - Up & Down Firing Speaker - Pair | AVStore