its about 2.4 a side minus the port walls speaker dis and bracing i havent hade a system in like 2yrs i cant wait and its tuned to what it say on the factory spec sheet cant remember
looks great, but you dont really need that many screws //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif one every 5" or so is plenty