Contour Enthusiasts Group Archives Forums Modifications Audio Hey Dave, I've got a Q 4 U 2

Thanks for the info.

Is that 1 cubic foot rear chamber for each sub or both subs using the same chamber?

1 cubic foot total for both subs (same chamber)

Hey Dave,

I ran the WinISD program and input my sub's parameters along with a dual woofer 4th order bandpass box. Here's what it came up with:

Front chamber: 1.18 cubic feet
Rear chamber: 1.90 cubic feet

port diameter: 4.02"
port length: 5"

Am I doing something wrong with the program or something?

It's showing a flat response from 45Hz to 75Hz.

Here are the sub's specs per the operating instructions:

FS: 36.8Hz
Qms: 3.04
Qes: 0.55
Qts: 0.44
Vas: 44L (1.5 ft^3)
EBP: 66
Revc (2 each @) Ohms: 3.6
SPL: 88.3dB
Xmax (mm) linear peak-peak: 14
Levc(mH): 0.72
Power handling: 200W continuous

Thanks for any light you can shed on this.

-Colin

Yes, the parameters you have listed are completely different than what i found on the internet. That will greatly affect the response and box.

BTW bandpass boxes usually have a narrow freq range of 50-85 hz and lower hz they suffer dramatically, and same with the upper hz. Now what is this cabin gain all about?

Cabin, room, environment gain, [edit]transfer funtion[/edit], all the same idea. In a car, due to its small volume, increases the level of sound by about 12dB/octave going down from about 40-50Hz. So, as the speaker starts rolling off usually in that same range, cabin gain will compensate and you end up with a naturally flat sound.

Don't forget transfer function on your list of synonyms!

Aarons right on, 12dB per octave is pretty typical and is used as a baseline. In small hatchbacks the gain will start as high as 80-100 hz.

Oops. My bad. Sorry for bringing up the old post.

Since you brought it back up. I now use Unibox. It is a much more comprehensive box building program. It's a bit more complex, and requires excel 2000, but it is very very nice.