Box volume on WinISD/BCAE seems way too small

[BMW M5]

I have been looking at putting two different drivers in my car that both have a unique "problem" in that WinISD and BCAE box calculators seem to recommend extremely small volumes (at a Qtc of .7)

The first driver is a SoundSplinter RL-p12 D4; the sealed volume I get is 0.300cuft...while Mike recommends 1.25-1.35cuft.
Qts 0.219
Qes 0.242
Qms 2.266
Fs 18.856 Hz
Res 6.26 Ohms
Ls 7.382 m
Lp 9.456 m
Rp 14.68 Ohms
Dia 250 m
(% shift) 33.20%
Vas 142.7 L
Mms 168.8 g
Cms 421.9 u
Bl 22.74
n0 380.1 m
Xmag 26.0 mm
Xsus 24.2 mm
Xmax 24.2 mm
SPL/Sensitivity 87.79 dB
Added mass 212 g
The other driver is a Dayton RS180; the sealed volume I get is 0.013cuft.--I have seen various recommended volumes for an enclosure for this mid and none are anywhere near 0.013cuft.

Specifications: *Power handling: 60 watts RMS/90 watts max *VCdia: 1.5" *Le: .90 mH *Znom: 8 ohms *Re: 6.4 ohms *Frequency range: 40-2,200 Hz *Fs: 38 Hz *SPL: 87.6 dB 2.83V/1m *Vas: .88 cu. ft. *Qms: 2.00 *Qes: .47 *Qts: .38 *Xmax: 6 mm *Dimensions: A: 7-1/8", B: 5-3/4", C: 3-5/8"


Can someone please explain to me what is going on?

[swordfish689]

Something is really wrong with those specs, make sure there right
i have bass box pro and i also get a very small size.

[BMW M5]

Thanks for looking into it, but I am pretty sure they are right. Crazy how the two drivers I am pretty sold on from reviews have this problem. I double checked the specs and they still seem to be right. Here are links directly to them.

http://www.soundsplinter.com/specs/rlp12_specs.htm

http://www.partsexpress.com/pe/showd...number=295-364

Anyone else have a thought on what is going on?

[95Honda]

Look at the electrical Q of the 12. That low and it is going to give you a modeled sealed box very small. The designer proabably found that they work good anyway in the size he reccomends....

[Drachir]

you had WINisd set to liters when you put in the RS numbers, that is why you got such a small box. I tried the same thing and got the numbers you got. PE has their VAS in cuft, not liters. I would go with a .3cuft box (Q=.75) for the RS driver so you get a flatter response to 80Hz and a steeper acoustic rolloff. You are using the RS's as mids, so they don't need the lower extension.
The small Qts of the 12 will net you a small box, this is how it goes. Although I get a box size of .55 cuft with an F3 of 60Hz out of WINisd.

[BMW M5]

Wow, do i feel dumb. I relooked at the specs a few times, but when both were off I obviously didn't look close enough and blamed it on the math.

Thanks for your help guys!!!!