port displacement
Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=97341
Printed Date: May 01, 2024 at 7:04 AM
Topic: port displacement
Posted By: mrbubbles00482
Subject: port displacement
Date Posted: September 22, 2007 at 9:52 AM
Im going to be building a box for 4 Kicker CVX 12's. Ive built boxes before and Ive decided to make my own for 4 12's, and not have someone build it for because of the cost. I was wondering about the port displacement, and if it would be best to split the box into 2 chambers, and have one port per chamber, or leav the box one hole box with one port. Ive calculated the box volume with the12volt's box calculater, but they dont have a square port calculator The box will be of two peices, a front wedge, and a back rectangle. Wedge Height 1-15 inches, Height 2-13 inches, Depth 21 inches, width 60 inches. Volume in cubic feet 8.4 Square back. width 44, depth 10, hight 11. Volume in cubic feet 1.9 Together the overall volume of the box is 10.3. The program I used to calculate the port said at 36 hertz the port would be inside width 6 by inside length 8, with a port length of 4.12 inches. All that is calculated for one big chamber, and if it is right then I need help figureing the port displacement. If making the box into two chambers would be better, let me know.
Replies:
Posted By: mrbubbles00482
Date Posted: September 22, 2007 at 10:13 PM
anyone? help on port displacement?
Posted By: andrewbutler
Date Posted: November 08, 2007 at 10:32 PM
Try https://www.linearteam.dk/ and download their free software...if you build boxes on a regular basis or even just everynow and then its well worth it to download it...download the "WinISD Pro" and it will give you port calculations and other measurements you need for your box...helped that helps bro ------------- andrewbutler
Posted By: mrbubbles00482
Date Posted: November 08, 2007 at 10:37 PM
Yes it helps. I have a program called Probox but, im not 100% confident in it so ill try it out.
Posted By: andrewbutler
Date Posted: November 08, 2007 at 10:42 PM
good luck
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andrewbutler
Posted By: mrbubbles00482
Date Posted: November 08, 2007 at 10:53 PM
Just installed the program and I got the same as my other program. Either way they both work so. Came out with the same results. Now I got to save the money to buy the stuff and build everything =]
Posted By: andrewbutler
Date Posted: November 08, 2007 at 10:56 PM
lol that is going to be a pretty freakin rediculous set up...is this just for the hell of it or some advertising for you or somethin??
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andrewbutler
Posted By: i am an idiot
Date Posted: November 09, 2007 at 5:12 AM
Mr bubbles you can use the box volume calculator to figure the port displacement. Outside dimensions of the port. Length X Width X Height in inches = Cubic inches. Divide that number by 1728 that will give you port displacement in Cubic Feet
Posted By: mrbubbles00482
Date Posted: November 09, 2007 at 7:53 AM
andrewbutler wrote:
lol that is going to be a pretty freakin rediculous set up...is this just for the hell of it or some advertising for you or somethin??
Its for competition. Ive changed what im going to do. My current set up it two kicker CVX's. Which are up for sell on ebay right now due to my transmission going out.
The new set up will be 4 L7 12's, 2 ZX 1500.1's, and a zx 350.4, 250 amp alternator and 2 extra batteries.
Posted By: andrewbutler
Date Posted: November 09, 2007 at 10:42 PM
lol thats rediculous man haha good luck
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andrewbutler
Posted By: mrbubbles00482
Date Posted: November 10, 2007 at 12:21 AM
Thanks man, it will be a while before I start this project. My system didnt sell, but I re-listed it. It might take a while, but once it does sell and I start this project ill post a new thread for pics and stuff.
Posted By: andrewbutler
Date Posted: November 11, 2007 at 2:34 PM
Great man that sounds good im looking forward to seeing them!!
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andrewbutler
Posted By: boogeyman
Date Posted: November 14, 2007 at 1:55 PM
i prefer seperate chambers...rule of thumb one chamber per amp.....if interested i can get into greater detail and an explanation just let the boogeyman know
Posted By: mrbubbles00482
Date Posted: November 14, 2007 at 7:33 PM
Yes go into more detail if you dont mind. My plan was one chamber, with supports and vented in the middle.
Posted By: boogeyman
Date Posted: November 15, 2007 at 10:41 AM
the reason i prefer seperate chambers is because the subs do not "interact" with each other and because seperate chambers "protect" the subs ......example lets say you have four twelves, one thousand watts rms and they're getting onethousand watts in ten cubic feet single chambered box, two of them blow, so now you have two twelves in ten cubic foot box thats five cubic feet a piece instead of 2.5 thats way too much air space, as airspace goes up power handling decreases, so now power handling may be 750 watts. and they're getting 1000 watts so you may damage those two subs. .........if it was individually chambered 2.5 per sub, if one or more subs blew you wouldnt run into this problem and plus you could listen to the working subs in the correct amount of airspace while repairs were made.
Posted By: mrbubbles00482
Date Posted: November 15, 2007 at 1:23 PM
Very good point, and I would prefer two seperate chambers, with 2 subs apiece, but the problem is the box is going to be assembled in two section, a back and a front, which will be built into the trunk. To put a partition in the middle to separate them would be to much of a hassle. Yes it could help in the long run of things, but with the way this box is designed its a real hassle to add a partition.
Im not ruling it out, but its not in the design right now.
Although, if I wanted two seperate chambers how would I tune each port?
18 hz and 18 hz = 36?
Or would two 36 hz tuned ports come out to a 36?
Posted By: boogeyman
Date Posted: November 15, 2007 at 2:59 PM
treat eachchamber like a seperate box, tune each chamber to 36 hz.....seperate chambers are not a must but just my preference ......what kind of vehicle is it going in
Posted By: mrbubbles00482
Date Posted: November 15, 2007 at 4:18 PM
Its going in an 82 oldsmobile cutlass supreme brougham. Its going to be a while before I can even start saving money to order things, and im not sure if im going to even do the project now. No money, and my current system has not been sold yet to fix my car.
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