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.
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.