My top (though by no means only) priority was minimizing power compression. It's hard to find a subwoofer that can "keep up" with a good high efficiency system. I think one of the reasons is that while the high efficiency system is loafing along at a handful of watts, the less efficient subwoofer needs maybe 100 times as much power to keep up. This is one of the reasons a horn subwoofer works so well. But if you don't have room for a horn sub, or if you want bass extension south of 30 Hz, then a more conventional system optimized for minimimal power compression makes sense.

You can find 15" drivers that will significantly out-displace the Acoupower. But I don't think there are any out there that can match its motor when it comes to minimizing power compression.

I'm a subscriber to Voice Coil, a loudspeaker industry newsletter published by Audio Amateur Publications. Each month Vance Dickason, of "Loudspeaker Design Cookbook" fame, does a review of a couple of drivers. The only time I have ever seen him go beyond reporting "just the facts, ma'am" and indulge in outright praise was in his review of the Acoupower woofer.

At this point I am very happy with the Acoupower, and have plans to build a big bucks high-end commercial subwoofer system around it.

Duke