2 type-r's would be all out crap in a tiny box.

Fi BL 12 $274-329 + shipping
New on Ebay with free shipping Alpine PDX 1000 @ 4 or 2 ohms $250-420

Box
29.45w x 12.625d x 20h/.75" MDF/port 3.6 x 5.83 = (displacement .18) 2.68 = 2.5 @ 35hz
RE Enclosure Calculator

 

What's wrong with 2.25 per type-r 12? Are you sure it was designed back in the 80s?

 

like i said..what do i know..but 4.5 for a pair of 12's for daily listening in a small car like that IS too big... try around 1.5-1.8 before displacement..you'll be surprised

 

Ok guys. Obviously 4.5 cubes aint happening in the back of my car.

I'm pleased with my hifonics brutus 1210 for now.

Its either one of two things for me.

Option a. Add a extra dvc 2ohm alpine. At which point ill be sending approv 400 to 450 rms to each sub

Option b. Sell the alpine sub. And get a single 12 of higher quality. And push the 1000 or so watts to it at 1ohm

Remember besides box space I need room for 2 amps. The sub amp and front component amp.

 

ok here look...Im usually not a big fan of manufacturer specs...but this is worth a look.

http://support.alpine-usa.com/produc..._SWR-1242D.PDF

if its the other model the box wont change just the final impedance
I believe it says something like optimum enclosure 1.7 cu ft
but really I dont know shet about boxes

 

heres the specs of the box that im currently running


2 cubic ft tuned to 32hz

 

running (2 jbl power series 12's in 8 cube box) is that too big?

 

Whats the box tuned to? 20-25hz?

 

You didn't account for subwoofer displacment, it gets 1.9. The difference between a Type-R on 500w and a BTL on 2k is huge, probably louder than 2 Type-R's on 1k. The Alpine will conk out at 1000W and a BTL can handle what, 3000?