hi frode, i'm in the process of finishing my four pi's. i've built the cabinets with the woofer mounted near the top and will externally mount the eminence horn, i wasn't thinking about improving the sound i just felt they would look cooler. i'm using the eminence kilomax woofer, it looks cool with the heatsink mounted over the dustcap. i'll post my review in a couple of days. happy tweaking!!