I own 3 pairs of design acoustics model # PS-6, they have a 6.5'' woofer and a 3/4'' fabric dome tweeter, they are a sealed enclosure. The crossover design is a simple 2nd order configuration. To me they sound almost as good as any high end speaker from 1985 or today. their sound is detailed without being too bright and the bass that comes out of that woofer is rated at about 50 HZ which is very good for a .38 cu. ft. enclosure. The tweeter is one of the most natural sounding tweeters that I've ever heard, very airy sounding with no harshness at all.
Hope this helps
If you can pick up a pair of PS-6's you wont be sorry!