Just so we're clear, its a Subwoofer not a speaker
I know it's a subwoofer. It's still a diaphragm and what is a diaphragm? A speaker/bass speaker.
And yes most subs (or higher end ones) come in DF (Down Firing) or the more typical FF (Front Firing) way. They produce slightly different effects that can be more or less beneficial depending on the shape of your room etc
I wonder how good the low frequency effects are on it, say 30Hz…
Also DF is usually for when you don't have neighbours to worry about
Interesting… Can it be done with any sub thats not down firing with custom feet. Or is it sub specific? Or even some modification to send it downwards? Or will it likely harm it…