4th Order Bandpass -- Four 15s

[cougarballa2k5 0]

Currently I have four Kicker Comp 15s doing a pretty good #, really pounding for a street beater on such a low budget.

In the vehicle, we have room for a 4th Order Bandpass. I used a calculator from www.carstereo.com to design one but doubt its accuracy.

Can anyone aid me in designing a 4th order bandpass, or link me to a site with theory/equations for one? Simple calculators are hard to trust w/o knowing the math behind them!!

[Eldorado 0]

80inches

dude is obsessed with bandpass

[Aaron Clinton 2,372]

80inches

dude is obsessed with bandpass

[mrray13 30]

actually, look into kickers own specs for their 4th order bandpass setups. they work great for street beaters! and are pretty damn efficient.

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[beerman 0]

You'll get the same results as the carstereo.com calc if you use the formulas from http://www.diysubwoofers.org

There are more advanced formulas that will give you the same results as WinISD if you built an excel spreadsheet for them. But why bother?

You can fire up WinISD and let it design one for you.

The long of the short of designing a bandpass: start with a sealed box where Qtc = 0.7. Determine Fcb. Build an equal size ported box in front of this where Fb(ported) = Fcb(sealed). Fb just determines port length and part of port area. Remember to include port displacement when you design the box.

That should yield a relatively flat response one octave below and one octave above Fb.

4 fifteens = big box. Easily 30 cubic feet of cargo space needed in the vehicle if designed for a healthy balance between SPL and bandwidth. Roughly 12 CF sealed, 12cf ported + woofer and port displacement.

This isn't something you'll be able to do alone, that's for certain.

[cougarballa2k5 0]

I kinda dropped this idea, but so you know, right now I have a 28 cubic foot box .

[beerman 0]

28 cubic feet in what vehicle? :eek:

[80INCHES 0]

just put each sube in 2 cubes sealed paying into a common 8 cube ported area

as far as port 104 square inch port

80

Edited May 19, 2006 by 80INCHES

[cougarballa2k5 0]

4 Door Ford Explorer :-D

Hey 80, what kinda of range is that box supposed to have, where is it supposed to peak? What tuning in the ported chamber?

Are you sure the ported chamber is big enough? Sounds small, I was figuring closer to 8 sealed 14 ported.

[80INCHES 0]

if u have the room to 14cubes ported go for it..the bigger the ported chamber the more efficient the box

as far as where it peaks and tuning freq ,i have to get back to u on that one..but i will tell u this..if u make your ported chamber 14cubes..u can do a 200square inch port and still be able to have a daily box that happens to get really loud

80

[cougarballa2k5 0]

Well here is what I have setup...

240in^2 Port Area

8.5ft^3 Sealed

14ft^3 Ported @ 52.45hz

2000RMS

I think that this is the best option for a serious 45 - 60hz ear burner and meter killer.

What are your thoughts 80? Is the ported side too big for the power I will be running? I think as long as I don't play material too far 40hz I'll be okay.

Think she will chit out a number? My vehicle peaks at 50hz.