I just opened up my EBS 210. Just had to have a look inside. The box is made from 3/4 inch baltic birch and there was no bracing inside. Not even butt joints. Probably dadoe joints (sp?). The walls had about an inch of poly filling (not on the baffle or around the port). The tweeter was a Selenium ST304 SUPER TWEETER and the speakers looks just like Seleniums too but they had a small EBS sticker on them. The box is 63 liters and the port is 11,5 cm in diameter and 8,5 cm deep. That makes it tuned to about 54 Hz if my calculations are right. Everything looked solid and simple. Sounds fast and punchie too. Can you tell Im bored and home being ill?