Originally Posted By: Mojo
I'm kind of worried that the 400 will sound similar to my 600. And actually being a sealed design, it may even sound better.


Why worry? Just enjoy that awesome 600. \:\) Its impossible to say without hearing it but I suspect the impulse response of the sealed 400 will be different than the ported 600. But even there its not clear without listening and examining a graph which will sound better in your room when blended with your speakers. A well designed ported sub can also exhibit excellent transient behaviour which contributes to that "tight" sound.

John