kmb504 Posted June 1, 2015 Report Posted June 1, 2015 I'm really interested in building a box with a kerfed port. I just don't know how to go about figuring it out. I want to have .74 net volume, tuned at 34 hz. The displacement of my sub is .05. It's an American bass vfl 8. I just want some help designing it. I want to kerf both sides of the port.
Triticum Agricolam Posted June 1, 2015 Report Posted June 1, 2015 This is help you with the kerfing, its not hard to do: http://www.caraudiofabrication.com/#!kerfing/c21v7 "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
kmb504 Posted June 1, 2015 Author Report Posted June 1, 2015 I know how to kerf, its just the numbers I'm having problems with. Like how long should I make my port to get the 34hz tune. Also, how do I calculate the airspace of the kerfed corners. That page/video is actually the first one I looked at and got me interested.
Jessica Posted June 2, 2015 Report Posted June 2, 2015 Normally half the radius of the kerf is counted as port. If you kerf both ends then do the same for each end. For figuring box volume figure out what you want first the figure out your port length needed using Torres box calc. Then design your port using the method I stated above. Alteratively you can use Google sketchup but you are going to know where to mark off to get accurate numbers. Rest in peace, walled 87 accord build log 03' Corolla build with AA Mayhem inside. My super random youtube channel and terrible camera work. Wiring comparison by CaptainzPlanetz Wire and fuse guide by Guest SyKo13
Joe X Posted June 2, 2015 Report Posted June 2, 2015 If you like the looks and you have the time, go ahead, subtract half the radius of the flare to the length of the port and add as displacement the lost net airspace due to the kerf, no other differences with a standard box.
kmb504 Posted June 2, 2015 Author Report Posted June 2, 2015 Thanks guys. Yea when I started trying to draw it up myself, I came to the conclusion that I need to start at the port length first
kmb504 Posted June 2, 2015 Author Report Posted June 2, 2015 It seems like ever calculator I use gives me a different number. I don't have a computer to download torres too. I tried going off of the box joex dimensions joex gave me for my original build. It comes out to 33.25 length I believe. The port is 8.5x1.5. The airspace for the sub is about .75. So should I build my port length to that?
Triticum Agricolam Posted June 2, 2015 Report Posted June 2, 2015 Different calculators use different formulas, also some factor in end correction differently, so you are going to get some slightly different numbers. If your tuning is off a hertz or two in either direction you will never know the difference. Your port dimensions of 1.5" by 8.5" by 33.25" long with .75 cubes of net airspace should put you really close to a 34 hz tune. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
kmb504 Posted June 2, 2015 Author Report Posted June 2, 2015 Thanks man, you guys are great. That's what I needed to hear. I really do appreciate all yalls help
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