Here are all 5 of the cabinets just before the front panels are attached.
The vented Left and Right Mains are 48” high, 9” wide, and 14” deep. They have a net volume of 61 liters and are tuned to 28.8 Hz. Each will be stuffed with 24 oz. of polyfill.
The sealed center and surrounds are 22” by 9” by 14”. They have a net volume of 27 liters and a Qtc of 0.81. Each will be stuffed with 16 oz. of polyfill.
The notch in one of the braces is to allow clearence for the tweeter.
The crossovers were attached to short pieces of dowel which is then glued to the rear of each enclosure behind the mid-woofers. Two crossovers are used per speaker, one for the tweeter and the other for the mid-woofers. The picture below is a tweeter crossover.