One of my friends gave me these and they sounded good to me, nice, tight bass being sealed:
http://www.audiovisionelectronic.com/im5/prod5/Subwoofers/enclosures/Al_PBB102.jpg
A little while after that, I took them out of that box and put them in a ported enclosure and stuck them in my old 73 vw bug and they POUNDED! They set off a few alarms on only 300w rms..!
In other words, I was happy with them..