clamshell. hard part is fitting them in side by side cuz i'm just a few inches shy of what i need. so...i gotta angle them now all over the place and glass em in. i got the rings all cut, lol and it may hate me, but i LOVE it. except i think my jig slipped and the ID is a little smaller, so i had to jig saw the circles on the inside to fit the speakers. lil jagged now but you wont see it. and it was the easiest way so to hell with it