They can be made to work well in wide BW apps such as with 'full-range' drivers, but for best performance overall they must be designed with a fairly low acoustic XO, which is too often ignored and why so many designs I've auditioned or seen posted on the various forums either have a 'hole in the middle' of its response and/or sound too 'phasey'/'muddy' through the mids due to excessive front/rear output timing errors to qualify as 'HIFI' for me.

Agreed, that wasn't my intent.

GM