I'm working my way through doing complete box designs for all the drivers. I'll have cut-sheets, 3D models of the boxes and complete design guildelines for building each model. I'll also include complete cost analysis and a "best guess" commercial equivilent. Obviously the "best guess" is just that. I can look at models and predict how much output they have based upon what we know about drivers, power and subs in general. Overall.... I can get pretty close because the laws of physics don't favor any one vendor.
Design #1:
Driver: Shiva-X 12" High output XBL^2 low-distortion driver.
Design Goal: Good output and musical performance in compact size with reasonable cost.
Amplifier: O-Audio Bash 500W with single band PEQ, 20Hz bass extension option, & 24db/oct LP filter.
Approx Build Cost: $394 + shipping plus MDF

Simulated output limits and extension with O-Audio amplifier & 20Hz bass extension mode. Notice we get good extension into the teens in a SMALL box. In-room response assumed a 8.5' ceiling, 13' Wide x 20' Deep room with the sub in one of the front corners. Listening position is centered on the room 2/3 of the way back from the front wall & seated.
The limits in this design are mainly from the amplifier @ 23Hz. You will start clipping the amplifier due to the slight bass equalization but only at very high output. You can move up to a 1000W amp but you don't gain much additional headroom because you reach driver excursion limits shortly after the amplifier limits. The O-Audio amp is a good choice for cost, features and its a good fit for the driver capabilities.
Design #2:
Driver: Shiva-X 12" High output XBL^2 low-distortion driver.
Design Goal: Good output and musical performance in larger size for more extension and headroom.
Amplifier: O-Audio Bash 500W with single band PEQ, 20Hz bass extension option, & 24db/oct LP filter.
Approx Build Cost: $394 + shipping plus MDF

Internal volume jumped to about 3.23 cubic feet. You can see you get a little extra extension and the same amount of amplifier power gives you a little more output, as you would expect in the larger box.
