Jordan92790 Posted November 14, 2007 Author Report Share Posted November 14, 2007 thats not enough port area...rule of thumb generally: 12-16sq" of port area/cubic foot so...my port hole needs to be bigger? What do you mean by 12-16 sq? Is that Square Inches? If so..what would be a good length and width for my port? Quote Link to comment Share on other sites More sharing options...
andym85 Posted November 14, 2007 Report Share Posted November 14, 2007 yea, i mean 12-16 sqaure inches of port area per cubic foot of box...so if ur box is 2 cubes, for example, then anywhere from 24-32sqare inches of port area. that could be acheived by making your port 6"h x 4"w (giving u 24sq")...or any other combination resulting in 24-32sq"... but if those are outer dimensions (14x30x30) then that is 5.88cubes gross (before any displacement). but the sub displaces .23 cubes, which knocks it down to 5.65cubes. a reasonable size port is gonna take up more than .65cubes, and since the smallest enclosure a 18"BL recommends is 5cubes net, then i think your box is too small to begin with.... if you can shoot for a box that is like 6.5-7cubes gross then that would probably be better... Quote i likes me some audio stuff... Link to comment Share on other sites More sharing options...
Derrick824 Posted November 14, 2007 Report Share Posted November 14, 2007 If you go with the minimum recommendations of 5 cubic ft box volume w/ 60 square inches of port area, the port will need to be 20.4" long for a tuning of 34hz. The sub & port displacement will be 1.2 cubic ft so your gross box volume will be 6.2. I did not take any bracing displacement into consideration. You need to make your box 14 x 30 x 31.5 external (assuming 3/4" mdf is being used). Quote Link to comment Share on other sites More sharing options...
Jordan92790 Posted November 14, 2007 Author Report Share Posted November 14, 2007 kk...So my new demensions are 15x35x35. I'm using 3/4 inch plywood. this will give a gross volume of 10.6 cubic feet. I plan on having a double baffle, my sub ( which has a .23 displacement), and a Port that is tuned to 34Hz. So..what would the demensions of my port need to be for the sub box to be tuned at 34Hz. I also need to know what kind "maze design" or what ever it would be called that I need to seperate my sub enclosure from my port? I was thinking of just a piece of wood that is mayb 13x35? I'm not sure on that. if anyone out there can would you mind taking this into displacement when firguring out my net cubic feet. Once again..Thanks alot! all comments are welcome! Quote Link to comment Share on other sites More sharing options...
Derrick824 Posted November 14, 2007 Report Share Posted November 14, 2007 Don't use plywood. Its not as dense and can resonate & delaminate. Use 3/4" MDF. Hopefully someone can come in a do a sketchup to help you with what the box should look like. Quote Link to comment Share on other sites More sharing options...
Jordan92790 Posted November 14, 2007 Author Report Share Posted November 14, 2007 Don't use plywood. Its not as dense and can resonate & delaminate. Use 3/4" MDF. Hopefully someone can come in a do a sketchup to help you with what the box should look like. No store in my area sells MDF bored. so I dunno where I can get it. I've asked hardware stores and they say that they don't sell enough of it to carry it. Can you order it online? Quote Link to comment Share on other sites More sharing options...
andym85 Posted November 15, 2007 Report Share Posted November 15, 2007 (edited) i can do get ya some dimensions and do something quick in google sketchup tomorrow.... and where do u live???? any lowes or home depot should have mdf...or any lumber place in general...if u cant do mdf then do birch, but birch is more expensive... Edited November 15, 2007 by amatt85 Quote i likes me some audio stuff... Link to comment Share on other sites More sharing options...
Derrick824 Posted November 15, 2007 Report Share Posted November 15, 2007 Search for cabinet shops in the yellow pages. They'll have some mdf. The goin price round here right now is $23 a sheet for 3/4". Quote Link to comment Share on other sites More sharing options...
Jordan92790 Posted November 15, 2007 Author Report Share Posted November 15, 2007 I live in a small town called LaFollette. It's in Tennessee. I've been to serveral lumberstores and ask if they carry MDF bored...and they don't because they don't sell enough. I can go to homedepot. There is one in Knoxville (I'm right by it.) and how big is the 3/4 sheet of MDF? and man that would be awesome if you could get a sketch for me. I really need these demensions because I'll be buying my wood soon. I'm forsure going for mayb 15x35x35 so I really only need my port demensions for 34 Hz Quote Link to comment Share on other sites More sharing options...
Derrick824 Posted November 15, 2007 Report Share Posted November 15, 2007 and how big is the 3/4 sheet of MDF? 49" x 97" Quote Link to comment Share on other sites More sharing options...
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