TRU SPEC Prefab Single 10" Subwoofer Enclosure Sundown SA 10v2
 
Tru Spec Prefabricated enclosures are simple, straight to the point, subwoofer specific enclosures dialed in precisely to manufacturer's specifications after displacements. These subwoofer specific enclosures will be versatile to many other subwoofers as well, so you do not have to use the noted driver on the enclosure, just be sure and double check your cutout.
TRU SPEC PREFAB SINGLE 10" : Sundown SA-10" with flush baffle
Material: MDF
 
Box External Dimensions
Width × Height × Depth
20.00" × 12.50" × 13.90"
Material Thickness
0.75"
Net Internal Volume
1.00 ft3
Tuning Frequency
35 Hz
Port Area
15.00 inch2
 
Cutout Diameter: 9.3"
Flush Trim Diameter: 11.5" 
Also fits the following 8" Subwoofers and are close to recommended specifications:
DC Audio Level 1 10" (this enclosure is spot on to DC's suggested specs after displacements.)
CT Sounds Strato 10" Subwoofer
CT Sounds OZONE 10" Subwoofoer 
CT SOUNDS Meso 10" Subwoofer
SKAR IX 10" Subwoofer
SKAR VD 10" Subwoofer
Audiofrog GB10 10" Subwoofer
Massive Audio GTX 10" Subwoofer
Massive Audio MMA 10" Subwoofer