6th Order 3 Chamber Bandpass

[Jet-Lee]

http://img447.imageshack.us/img447/5556/juansboxbp88hh.jpg

left chamber will be tuned for 90hz with 2 - 4"x2.15" ports
right chamber will be tuned for 60hz with 1 -4"x2.75" port
bottom (airspring) chamber will be tuned for 30hz with 3 - 2"x18.3" ports

top chambers are 1.61 cubic feet
bottom chamber is 1.4 cubic feet

Will be running RFP-4412's

thoughts?

EDIT - Title fixed.

[drewgray]

same as i said over on ARi. I hope you don't want any sound quality and do desire a narrow bandwidth going for SPL.

[Jet-Lee]

It should perform surprisingly well from 30hz and on. Especially at 50hz and 70hz.

[drewgray]

What makes you assume this? 6th order and even more so 8th order bandpass designs have very very narrow passbands. And if you go below that band, say bye bye to your subs.

These are extremely hard to get correct, good luck. What are you using to model this enclosure that you think it will perform well from 50-70hz?

[Don Juan]

it better be correct, this shit is going on my car!

[5point_Slow]

wtf is 8th order

[drewgray]

The design that he has pictured isn't an 8th order design, its a 6th order. An 8th order has another filter element (volume) that filters the output of a 6th order box.

[Jet-Lee]

The fact that all three volumes are tuned differently allows it to have a wider band.

Using WinISD.

The volumes have changed size now. The airspring chamber (30hz) will now be 2.337 cubic feet with the same ports, except 10.375" long. The other two will be 1.185 cubic feet. 60hz with 1 - 4"x4.875" port and the 90hz with 2 - 4"x4" ports.

EDIT - 6th Order 3 Chamber Bass Reflex, my bad

[drewgray]

The subs are going in the big holes in your drawing, correct? One on each side of that center divider? Is this correct?

[Jet-Lee]

yes. Bottom mounted facing down, in phase. The box may be flipped over though.

[Don Juan]

will this be a better box than the one we already built lee?

[Jet-Lee]

uh huh

:yes:

yup

yessir

fo sho

[Don Juan]

sweet

and far as all of these "hz"

mines set up with 125hz, but i can drop it down to 50hz or what ever, dont know what the hell it means, but i can change it

[Jet-Lee]

It's the pitch, or tone.

What you have yours set on, is the crossover. At which tone/pitch it stops feeding sound out to the amp.

[Jet-Lee]

Juan, you gave me too much time. I've fixed the bottom ports so it's one big slot port now, .75"x26.5"(wide)x23.5"(deep). 20in^2 port area vs. the old 9.5in^2.

http://img416.imageshack.us/img416/3455/juansboxbp8slot8ks.jpg

This one is to scale. Well, almost. I had to shrink it 50% on the computer. But the real drawing is scaled 12.5"=4cm.

[Don Juan]

so will this kick ass even more?

[Jet-Lee]

If port noise was an issue, it's not anymore.

[Doughdog]

Why? what is the advantage of this box? It sounds to me like the guy that comes in the shop and says "I need two 8's and two 10's. 'Why?' because the 10's will play lower than the 8's and the 8" subs will play my high bass" :rolleyes:

[Jet-Lee]

Why not?

this will yield better volume than the current box that he has them in now.

I will be making one for myself, except using two tens, to have an idea of what it sounds like, before telling Lude whether it's worth thetime or not. I have no problems ripping my own shit apart to experiment, but I don't want a friends product be the guinea pig and sound shitty.

So, I ask again. Why not? Why not venture and see how this design will sound? Why not try it and see? If it is shitty, then I know not to go with that design again, if it rocks it was my design and I'll be proud.

Why not?

[Don Juan]

its hella fun to bouild too, especially when you fuck up :haha:

[Jet-Lee]

you mean like, 1/4" off, or make a squiggly angle cut? :ph34r:

[Don Juan]

yep, you sure messed that up there buddy

[Jet-Lee]

The "1/4 off" thing wasn't me, it was the douche at Lowes! It sounds fine though.....