Thoughts start with the Boogieman
The TB driver is a monster for its size, and fortunately, it comes in both neodimium and ferrite versions, at a nearly 2x price delta. My take is they're interchangable, and my simulations agree.
Mobeer suggested a low-profile 12" with modest Xmax befitting a car audio application. I will note the absence of an Sd (cone area) spec in their literature, so I suspect this 12" radiates like a much smaller driver. Still, Sd of a 12 is ~500 sq cm compared with 140 sq cm for the TB W6, which makes 4x used in Boogieman equivalent or better. Where the BOSS driver shines is sensitivity, it has a 12 dB advantage over the little TBs, and they only make up half of that with 4 drivers. Conversely, the TBs have over 2x the excursion capability, so there's likely a Hoffman's Iron Law tradeoff here - size, extension, sensitivity, pick 2.
I already had a W6-1139 simulation, so I looked at the boogieman configuration. I think his write-up is off on box size; I don't like the result at anything less than 2 cu ft., but I like the response options you get when tuning the box to 30-40Hz.
- 30Hz maximizes extension and with room gain, overall flatness of response with an F10 of ~23Hz. 2 port of 4" diiameter about 32" long
- 35Hz is quite flat anechoically, so you hear all the room gain, has an F10 of 25Hz, and is achieved with dual 4" ports of 24" length.
- 40Hz provides a nice thump at 45Hz due to a 1.75dB peak, but the dual 4" ports are now only 16" long and F10 is more like 30Hz.
This is with Darren's 30" port, a 31Hz Fb, and clearly an "extended bass shelf" alignment (Fb <= F3 with a downward tilt).
I'll also note that I did a quick simulation of the BOSS and it's a strange beast. In 1 cu ft sealed, I'm getting F3 of 47Hz, vs. their 45Hz, so we're close, but 100W will exceed Xmax and Qtc is greater than 1, so there's a big bump in output at 70Hz per BOSS and 85hz per Unibox sims. This isn't what I want in residential HT. Plus at 100W, you're not making 110dB while the Boogieman will do 116dB with a 500W amp, and still has excursion to spare. I will note the TB are only rated for 50w, 100W peak, so don't expect to run sine waves at this SPL, but for music and HT, you want amp headroom. Conversely, 500W is only 2dB louder than 300W...
Hope this makes sense...