Having played around with the new PB13U and PC13U for a week,below is my short reports .
The drivers built is . Even push hard (tune at 10hz/sealed,room gain = off) , the drivers still no sign of bottoming , clean and good bass .(Using Flight of the pheonix to test)
There is a new adjustment on this new ultra -- Room gain.
You can set small,medium,large or off(see instruction booklet) . This is to compensate the room gain on different sizes of rooms. The effect is to slope down the deeper freqencies, using your own room to increase back so to get a flatter response .
I myself set to "off" because I want powerful deep
Compare PC13U to PC12U , PC13U is taller . PC12U will tend to have loud port noise when a sudden powerful deep bass chime in . PC13U also has but very faint , so do the PB13U .
Overeall initial impression Will try to watch more deep bass materials in future and see how .
Both is as powerful . "Very faint" refer to port noise . PC12U(set at 10/15hz) used to have loud port noise when SUDDEN push hard(example:hill have eyes 2 , scene when a head pop out from toilet bowl.)