My 448's sounded a lot better with the E11 especially the bass. Unfortunately, at around 4 or 5 (in the volume level of the E11) you'd hear some cracking sounds. If you really want the deep booming sound in the 448s, it is likely unable to handle it even with an amp. Nonetheless, it still sounds great with medium range volume using the amp.
the 448s are known to distort easily when the low's are pushed.
im not sure about the other 4x8 cans, has anyone tried?