How-To:Enclosure in Sketch-UP THIS TUTORIAL IS NOT ONLY FOR SKETCH-UP. Part one *PART I* For the first tutorial I will show you step by step everything I do to design a bass reflex with a slot port. Specifications of the enclosure are random say for a single 12 to get loud down low. - 2.75 cu ft net - 48 in^2 of port area - port length of 37.25" long. Driver displacement is usually around .01-.1 cu ft. I usually add .2-.4 cu ft to the net volume to account for driver displacement and additional bracing. Before we design anything we need to know the GROSS volume. The port will be a slot port 12" tall by 4" wide...assuming 4.75" wide for material thickness. 12 x 4.75 x 37.25 = 2123.25 in^3 divide that number by 1728 to convert to cubic feet for 1.228 cu ft..roughly 1.23 cu ft. Total GROSS volume 2.75 + 1.23 + 0.2 = 4.18 cu ft internal. Now that we have all the specs of the enclosure lets make it fit into whatever we need. In part the basic steps are multiply the gross volume by 1728 to convert to cubic inches. Then divide that number by two different numbers...the last number will be the last dimension found. Take the GROSS volume 4.18 cu ft and multiply by 1728 to convert to 7223 in^3 Internal enclosure height is 12" for port height. 7223/12 = 601.916 Now we can either set the width or depth. Internal enclosure width will be 26.5" 601.916/26.5 = 22.7138 but we can round to 22.75" because the difference is very small. So now the final exterior dimensions with material accounted for is 28" wide x 13.5" high x 24.25" deep *Part II - 3D Modeling* First off delete the retarded guy that is standing next to the axes if he's there. ******notice****** -all dimensions are set by using the number pad and enter while using the various tools. -traced tape measurements are erased with the eraser tool. Click the RECTANGLE box, click and drag out the rectangle but do not click to set the size...from here you can just enter in " 24.25, 28 " and press enter and that size rectangle will be made. Now click the PUSH/PULL button and pull the material up .75" by clicking and entering in the dimensions followed by the enter key. Now from here I usually lay out everything with the tape measure tool. For starters the next step is to lay out the outer panels thickness/ Then I lay out the port walls first by using the tape measure and clicking on the sides and pulling out 4". Then from there pull out the material .75"\ Next I use the pencil button LINE tool and trace over the dotted lines to establish the vertical panels. I usually start with the back panel and work my way around. Now for making the port 45 degree corner. Using the tape measuring tool make the base line. Then using it again click from the inside corner and leave the pointer on the line...press "4" then "enter". This will make a small mark 4" away from the inside port corner. Using the protractor I make the port corner perpendicular to the base line. Then with the tape measure pull out the .75" material thickness...then trace with the LINE tool. Here I show how to copy the port corner to add it to other corners of the enclosure. Using the SELECT pointer click on one wall of the 45. Press and hold "Ctrl" and click the other three walls. Copy and Paste the 45 and then using the "ROTATE" tool rotate the 45 to line up with the corner correctly. Using the "Move/Copy" tool drag one side of the 45 to the port wall. Then the other side to the other port wall. The 45 will "stick" to the walls so its pretty easy to line it up in the corner. Now we have the base layout of the enclosure. From there I usually select the whole thing and copy/paste it over to the side for later dimension layouts. Here is the fun part. Pulling up the vertical panels. I always start with the rear wall. Don't know why but it is just a person preference of mine. After pulling up the rear wall 12" I use the LINE tool to trace the bottom where the base panel meets the vertical panel. Repeat after pulling up each outer wall. If not the final enclosure will look like a single chunk of material and will have no differentiating panels. It's really coming together now. For the baffle hole ORBIT around to the front. Mark the center of wherever you want the cutout to be. Trace out the hole...this radius being 5.5 for average 12" inch sub cut out. Use the Push/Pull and push the circle in. Result should be this. The end result is this The net volume is 2.98 before driver and bracing. Next step I'll add in bracing to bring down the volume to ~2.75 cu ft.