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View Full Version : helpin a friend wit a box for 4 12's ????



jmkanek
06-12-2009, 11:26 PM
ok im designing a box for a friend of mine, he has 4 pioneer championship sereis 12's got a box designed that is 42 wide, 15 1/4 deep, and 32 high. port is going to come out of the top going to be 40.5 wide and 3 1/4 deep, giving it a port area of 131, tuned at 38 hz. does this sound about right, the box comes to 9.8 cubic feet befor displacements, and is 131 too much port area or would it be alright

illbmeubu
06-12-2009, 11:34 PM
Sounds bout right. 131 is cool for port area. Most do 12-18 inches per cu ft of the box

ABSOLUTEAUDIO
06-12-2009, 11:34 PM
what is the length of the port?

jmkanek
06-12-2009, 11:36 PM
port will be 16 inches long

ABSOLUTEAUDIO
06-12-2009, 11:39 PM
any idea on sub displacement?

ABSOLUTEAUDIO
06-12-2009, 11:39 PM
You have around 8.58 after port

jmkanek
06-12-2009, 11:41 PM
ill look right quick

jmkanek
06-12-2009, 11:46 PM
.076 per sub is what the owners manual says

ABSOLUTEAUDIO
06-12-2009, 11:55 PM
Yes your port area is good, and you would have around 2cuft per woofer! build it :D

jmkanek
06-12-2009, 11:55 PM
awesome what would the final tuning be after displacements and everything

ABSOLUTEAUDIO
06-12-2009, 11:58 PM
what is the port made of 1/2" or 3/4" mdf?

jmkanek
06-12-2009, 11:58 PM
will be using 3/4 mdf

ABSOLUTEAUDIO
06-13-2009, 12:01 AM
I would say around 40hz

jmkanek
06-13-2009, 12:02 AM
ight man awesome, may cut the port to 3" high so it will be tuned a lil bit lower, thank that would give around 37-38 hz thanks for the help btw

ABSOLUTEAUDIO
06-13-2009, 12:04 AM
no problem! You can give up a little port area to lower your HZ:)

jmkanek
06-13-2009, 12:07 AM
ight thanks fer the help man, we prolly start workin on the box tommorrow,

jmkanek
06-15-2009, 09:10 AM
got the box built, but we are going to have to add more braces inside the port to keep the back of the box from flexing, my question is will this lower the tuning or raise the tuning by adding some braces in the port

jmkanek
06-15-2009, 11:06 AM
ne one i was just wondering what the bracing is goin to do to the tuning, raise or lower it. thnks

mbrooky
06-15-2009, 01:15 PM
i believe the tuning goes higher the more airspace you take up and port size doesn't change.