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hemi=22s
08-09-2008, 11:41 PM
ok i searched here and google, got a general idea of whats up differnec between 4th and 6th order

i am building a box with RE MT's blow thru the rear deck on the impala

what size box should these go in same spec as ported??

JG903
08-10-2008, 01:04 AM
What sized subs and how much space do you have to work with?

hemi=22s
08-10-2008, 09:20 PM
What sized subs and how much space do you have to work with?



got 13 ft 3 total air space and i have 4 RE MT 15"s i can use (up to)

jdawg
08-10-2008, 09:22 PM
you aernt gonna fit 4 15's in a bandpass with that volume, 2 maybe. I would do a 4th order and port it into the cabin, even then you might be stretchin in

TSGP
08-10-2008, 09:23 PM
you could probobly squeeze 3 15s in there.

1.5 cubes per 15 sealed and as big as possible on the ported

jdawg
08-10-2008, 09:23 PM
you can mess around with these programs http://www.carstereo.com/help/Articles.cfm

JG903
08-10-2008, 09:43 PM
Listen to TSGP.
Small sealed chamber. Huge front chamber with lots of port area

hemi=22s
08-10-2008, 09:59 PM
do i have to tune the front area or no

2 or 3 is fine so 1.5 on the sealed portion and as big as possible on the ported portion

TSGP
08-11-2008, 12:20 AM
The front chamber is what gives you your tuning. Along with the size of the sealed chambers.

1.5 per 15 is a good rule of thumb.
2 per 18.

Too big will have too low of a peak and you'll have a ton of fluttering. Too small and you'll peak too high and blow subs trying to force them to play music.

The ported chamber you tune just like a normal enclosure. More area or shorter port tunes it higher. Less area or more length tunes it lower.

You have to play with tuning a little bit to get a happy medium

PV Audio
08-11-2008, 12:48 AM
PM 80inches. He's fairly adept with bandpass ;) :)

TSGP
08-11-2008, 01:23 AM
no offence to 80 at all...he knows what he' talking about, but I helped build the worlds loudest super street van (uses a bandpass) and I have bass raced over a 157 using 4 18s, 8 20.1s...and 2 batteries, also in a bandpass

PV Audio
08-11-2008, 01:29 AM
Or PM this bloke :)

hemi=22s
08-12-2008, 10:43 PM
any help is appreciated. so 4 is out of the question???

2 or 3 is better lmk what will work best and i will get it done ill get the dimension once i get finished wiring the car and extra batteries the space i have for box and how big a port i can do in the dash

JG903
08-13-2008, 12:56 AM
You should try to PM TSGP. I believe he has actually used MT's in a bandpass before and was pretty loud.
You should probably use 2 subs just so you wouldn't get a weird load to the amp.
Just a shot, maybe try 3 cu. ft net sealed and use the rest of the space as the front chamber and tune to 35 hz.

hemi=22s
08-13-2008, 01:00 AM
how do i tune the front chamber same as ported enclosure??

i'll pm tsgp and see what up with the design of this i got the port space illl post dimensions i can use tomorrow for blow thru here is pic
http://i261.photobucket.com/albums/ii80/56acebtown/IMG_0260.jpg

should be big enough???

Random1010
08-13-2008, 01:02 AM
im trying to do a bp with 2 18"s as well..

hemi=22s
08-13-2008, 01:03 AM
im trying to do a bp with 2 18"s as well..

sweet bump for da bp box u doin 4th or 6th order bp

JG903
08-13-2008, 01:04 AM
Yes, tune the front chamber just as a ported box.
The cut out looks decent.

Random1010
08-13-2008, 01:05 AM
sweet bump for da bp box u doin 4th or 6th order bp

depends on the size requirements. Have like 13 cu. to work with..
Rough plan was 4 cubes sealed for the pair and 8 cubes for the ported at 30hz..

energizedsbs
08-13-2008, 11:31 AM
just a question. isnt a bandpass box tuned different? i have a 15 in a bandpass that 80 designed. its tuned to 55hz which was like around 30hz in a normal ported enclosure. just wondering about that.

PV Audio
08-13-2008, 02:21 PM
That probably means that it peaks at 30hz, or the lower end of the passband rolls off at 30hz.

JG903
08-13-2008, 03:41 PM
I have always been told that tuning a bandpass high is for spl purposes just like vented enclosures.
Alan told me to make a effecient 4th order enclosure to make the front chamber 18 cubes :eek: tuned to iirc 40.

Also if you read some literature that some manufactures publish about box specs they tune thier bandpass boxes to like 40hz as well. For instance the JBL 15" W15GTI series sub bandpass specs the front chamber is tuned to 40 hz for a daily box.
Link here: http://manuals.harman.com/JBL/CAR/Boxes%20and%20Parameters/W15GTi_rev_f.pdf

PSturmer
08-14-2008, 06:01 PM
4th order is a sealed rear chamber and ported front. these are easy to design and build. 6th order both rear and front chamber are ported at different frequencies. these are known as "bass reflex" boxes. much more difficult to design and construct. generally 6th orders are hard to get a flat curve for daily and they are very difficult to function in an spl application. bose uses 6th order for the subwoofers in home audio. (they also hold the patent to this design)