If you like that box, then build it. As soon as you change it, it's not the same box and won't work the same.

This thread is actually getting funny - we have an installer wanting a handout solution and a contributor continually suggesting drivers the OP doesn't want. I'll chime out now and let you guys figure it out.

 

Being an installer has nothin to do with this situation. There are MANY different installer out there. Ever give any thought to the fact I may be into the electrical side of things and not the audio side of things. I don't want to invest hours of my time building a encloser just to be unhappy with the results. This is a forum where people post problems in hopes of a solution and not smart *** comments and sarcasm. You Dukk obviously know what im trying to do and how I should be doing it but offer no solutions but build it and see so when it doesn't work you can sit back and have a laugh. I have seen to many botched cut throughs in my area that do not perform at all. Maybe I should be posting this on another forum to see if I can get a little more help.

 

I gave up long ago.... lol

"rbgnwa45" have you figured out port frequency calculations yet? 4th & 6th orders aren't like calculating a slot port.

 

You never tryed Paul.

 

If I were you, I would build an enclosure with 4 12" subs. Make the port down the center, and tune it to around 36hz or so.

Make sure that it is mounted about 1/3 of the way down the cab.

I think the most important piece is the cutout. Make a 'port' that will fit into it. Make it as long as possible and start tuning, cutting it down little by little. This will result in a 6th order.

 

No, I've never designed a BP or a horn. I didn't think it was a 4th or 6th OBP because there is nothing sealed and a 6th order is a driver in two boxes but that design has them seperated. To me it looks like a box in a trunk and the area outside the port looks like trunk space and not another tune. I was drawing design layouts and not a finished box, although I will tinker with it. I suggested two slanted 18's because he could foreward-fire everything.

If your box is going to be 18" high, the port is going to be 16" high with 1" MDF, and if using 10 sq.in. per cube (with 4 15" M series in 24 cf3), you need a port that's 16h x 15w (240"). So it's like using 5 15's across (81.5) but you can only fit 62" (?) so 4 angles need to make up for 19.5", which means the approximate length from the end of the port to the cab needs to be... 47.33"? Starting baffle angle at 26.32 degrees and then +26.32 for the next... if I did that right... probably not, maybe the length from the end of the port to the cab was half of 47.33".

Right Triangle Angle And Side Calculator

This ain't a slot port? A port calculator says double port area (240) is needed for a BP, which means the angles would be near 90 degrees.

16h x 15w x 17d in 24 cf3 = 30hz, 35hz = 9.2d.

I found this on Termlab forums:

The formula for an exponential horn is:

Ax=At*E(2X/Xo)
Ax= area at distance X in sq meters
At=area of throat in sq meters
E=exponential
X=length in sq meters
Xo= 2/K
K=4*Pi*Fo/c
Pi=3.141592
Fo=horn tuning freq
C=speed of sound is meters/sec which is=344

Too bad I don't know what to do with any of that.

http://melhuish.org/audio/horn.htm#disclaim
http://people.ne.mediaone.net/bennyone/lowhorn6.htm
ROYAL DEVICE Hi-Efficiency Loudspeakers Audiophile speaker systems High fidelity systems Sistemi di altoparlanti hi-end HiFi ed Alta Efficienza Lautsprecher Diffusori acustici stereo Enceintes acoustiques

M 15 D4 specs at the bottom
http://www.powerbassusa.com/sites/po...b_oman_web.pdf

 

He can do 4 15's in a "V" shaped blowthrough. Been done in a certain yellow Dakota about 10 years ago from Windsor. Owners name was Derek. It slammed. Had all RF products, chrome amps. Was a really nice truck.

 

The Subwoofer DIY Page - 6th Order Bandpass Systems: Frequency Response Calculations

To calculate the frequency response of a 6th order bandpass system,you will need to know the following:

Vas = equivalent air compliance (litres)
Vf = net front volume (litres)
Ff = front volume tuning frequency (Hz)
Vr = net rear volume (litres)
Fr = rear volume tuning frequency (Hz)
Fs = driver resonance frequency (Hz)
Qts = driver Q at system resonance
Ql = box losses (Ql=infinite (10000) can
be assumed for most cases)

Then at frequency F,

a = abs(Ff^2-Fr^2)*F^4
b = F^6
c = (Fr^2/Ff/Ql+Fs/Qts+Ff/Ql)*F^5
d = (Ff^2+Fr^2+Fs*(Fr^2/Ff/Qts/Ql+Ff/Qts/Ql)+
Fs^2*(Vas/Vf+Vas/Vr+1))*F^4
e = (Fs^2*(Ff/Ql*(Vas/Vr+1)+Fr^2/Ff/Ql*(Vas/Vf+1))+
Fs/Qts*(Fr^2+Ff^2)+2*Fr^2*Ff/Ql)*F^3
f = (Fs^2*(Fr^2*(Vas/Vf+1)+Ff^2*(Vas/Vr+1))+
2*Fr^2*Ff*Fs/Qts/Ql+ Fr^2*Ff^2)*F^2
g = (Fr^2*Ff*(Ff*Fs/Qts+2*Fs^2/Ql))*F
h = Fs^2*Fr^2*Ff^2
i = -b+d-f+h
j = c-e+g
dBmag = 20*log(a/(i^2+j^2)^.5)

 

omg bloody hell. wanna build me a rocket ship. mad professor lol

 

Been there... read that... long time ago. Have you done the math? I suggest inputting it into Minitab (my personal favorite) or maybe even excel. Then save it, plug in the variables and save most the BS. It's said to be one of the best calculators. Only problem is making sure you have the right volumes and displacements calculated properly.

... and your missing a big part of that info, lol. There's SO much more to it then that.