Hi Thomann!
We ordered this subwoofer in order to strengthen the lower end of our PA system. Our system has consisted of two Yamaha DXR15's, which have taken care of the whole frequency spectrum. Well, adding the sub improved the overall sound a bit, but there's a limit to what one subwoofer can do.
This sub clips at a pretty early stage, so if you are going to make a crowd of 100-200 persons drown in bass, you'd probably need 4 of these bad boys. Of course one could say that you get what you pay for, but I suspect you might get more decibels per euro with some other products.
One of the greatest advantages with this product was the decent crossover, connectivity and the weight. I can tell you, I've moved way heavier subs than this, and it was almost enjoyable to move this one around. Also the freedom of adjusting the crossover frequency was really nice, you don't get that with every subwoofer.
Where would I use this sub? This sub is probably loud enough to make a home system work very nicely, maybe even smaller gigs. If I would need to transport a compact PA system around a lot, I would probably get one of these.
Still, I probably won't buy this product any time soon, unless a very specific need appears. Buy it if you need something portable and okayish, otherwise reconsider your options.