Physics of downward firing woofers


Ok ... this question will show my complete lack of knowledge about physics ... but here goes anyway:

Every now and then I come across a speaker with a downward firing woofer. I wonder: why don't the sound waves bounce off the floor back towards the speaker, rattling the bejeezez out of it and / or messing up the woofer itself?

~Jim
128x128jimspov
Very timely topic for me!

Theories aside, I am interested in actual experiences of others comparing down and front firing subs in practice.

My experiences with front firing bass drivers (conventional box speakers) versus downward firing (as is the case in OHM Walsh speakers) is that floor interactions are perhaps the biggest issue to address first in either case to get bass under control. Its usually a yuge problem with suspended plywood floors found in upper levels of most homes. Not a problem with solid concrete foundations found at floor level in most homes.

I only have experience with front firing subs to-date and same problem there.

Have been debating getting a new sub and not sure about whether to get front versus down firing. There are very good quality subs of both persuasions out there it seems.
"....actual experiences...." *G* OK...

Agreeing with Erik @ 11:25, my modest bottom-firing sub is up against the wall.  If I opt to listen to my front-firing speakers, they pass up to a pair of 12" +/- 15" above the concrete floor. They in turn pass up to a 6' active with a 6" passive physically above the 12".  Both are aligned +/- 30" from the back wall to accommodate the dipole ribbon above them that takes it to top....

...when I'm not listening to omnis, anyway. *S*  Not your typical approach, but I like the results.  All the bass and lower mids one could want, unless you're into 'burping' in the car.  Not the sort to hang out here @ AG... ;)
A successful design with downward-firing woofers were the Snell Type A's. Excellent bass extension and impact! No need for a subwoofer! I own the Type AIII's and can attest to this - some of the best dynamic bass available! And the against-the-wall placement frees up a lot of space in the listening area!
Anyone have or compared the Sumiko subs? They seem well received in home audio circles. They use a downward firing active driver and a front firing passive, which is said to help make them integrate easier. Seems to make sense.
Maybe the only real listening-oriented problem I could say that I’ve ever really run across in downward-driver designs is that, as a rule, I find there can be a big difference really between "bass impact" (or "wallop") and "bass dynamics". It’s possible to have lots of impact and yet still have (sometimes) even dreadful bass dynamics. Yet many people might be inclined to say that that kind of sound is as good or even preferable to one that tics all the traditional boxes in bass reproduction (???). Although it’s usually not to quite that objectionable degree audibly, that to me may be about the worst thing you can find yourself getting into with downward designs, that and the slight loss of timing that seems to go with it. But, it’s possible these designs may work as good or better in some "problem rooms" where there may not be enough space to properly present a direct setup. But, that’s one reason why I say above that dynamics can be better with a direct setup. They are not necessarily any stronger, they are just presented more fully intact.

I know when trying to assess downward subs that there tend to be sooo many other variables involved (placement, room size, etc) that establishing the exact audible effect the downward arrangement actually has can end up getting pretty intractable.