4TH ORDER MADNESS

[DaPlague]

ok so im fighting this 4th order im in need of information of how to port these ive hear more area the better but does it get to a point where it "too much" port area?

is there a set number that works well?

is vented or aero better or worse?

ive read countless forums and build logs and non seem to answer those questions. below is info about the box and also the subs thanks for all the input!

2 cubs seales 5-6 cubes ported (that number is being messed with but 6 is max and 5 is min)

4 rockford p3 10s

2400w amp

thanks for help if needed i can upload a pic of the design if necessary

THANKS!

[mrd6]

What are you tuning to?

General rule of thumb starting point is half your cone area...and with those subs I would go a bit smaller than that. If you can build it so that you can adjust your front port that will be best. Its going to take some testing.

[DaPlague]

55-60 that area

[DaPlague]

what im getting at is this http://www.carstereo.com/help/Articles.cfm?id=31 says alomst 200^2 in of port it just sounds high to me but i havent done this that long so im not sure what normal numbers are im thinking of going with a 13" aero this will give me 113^2 in of area or 18^2 per foot is this good or should it be bigger? and is the term "more port area the better for a bandpass" correct ?

[mrd6]

More port area is not necessarily better. The lows in a bandpass come from compression, if you have too much port area you will lose musicality and efficiency.

[mrd6]

I would try around 100sq in to start. And FYI a 13" aero is 133 sqin...stop thinking of port area as sqin/ cubic. Just disregard that entirely.

[Hugh G. Rection]

and is the term "more port area the better for a bandpass" correct ?

if that was true then nobody would discussing ports on them, they would all just be open faced.

[fecupe2001]

Rockford P3 10" T/S parameters acording to web page:

EBP = FS/ QES

EBP = 28 / .63

EBP = 44

Nice subs for a 4th order bp

Rear chamber depends on many factor, such as, power, desired bandwith, low lows, etc etc,still, this is a fine way to get the rear chamber size

.7 / QTS ^ 2 -1

.7 / .56 ^ 2 -1

1.57 - 1 = .57

Each sub should perform just fine on .57 per, x4 this means 3 cubic feet should be perfect for the rear chamber

Front chamber, well, lots of people like to do the ratio thing, i honestly don´t care about that, i always test as much as i can the proper size for a ported box on each sub i use, and honestly speaking, it always work for me using about 75% of that proper size i get on ported boxes on the front chamber of the 4th order bandpass, for example, if 1 c/f is the best i´ve tested on a ported box, then i use about .75 c/f for the front chamber on a bp

Those subs work awesome in about 1.55 cubic feet on a ported box , at least that´s what i got when i tested those things before

1.55 - 25% = 1.16

1.16 x 4 = 4.65 cubic feet

I would do then, 3 cubic feet sealed chamber and 4.65 cubic feet front chamber, 1.5 : 1 ratio for those who likes the whole ratio thing

Port size? that´s another story, i would start big and then shrinking it until it´s loudest to your ears and plays the bandwith you like, if you go with aeros, then i guess maybe a 7" aero would work? who knows