Triticum Agricolam Posted November 22, 2014 Report Posted November 22, 2014 If I were to pick between the two numbers I'd go with JLs just because if anything it will tune you a little on the low side. It's a lot easier to raise tuning on a box than lowered it. The important thing to remember is both formulas are just approximations and will only get you so close. Though the 2" difference between the two is only going to amount to about 1 Hz in change which you would never be able to hear. "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:
user18436572 Posted November 22, 2014 Author Report Posted November 22, 2014 If I end up with 33hz, I'm cool. I just don't wanna be above like 35. Thanks so much for your help! Btw, I looked, but I didn't find it. Can you link me to the formula on the JL website?
Triticum Agricolam Posted November 22, 2014 Report Posted November 22, 2014 Here is the article: http://www.jlaudio.com/header/Support/Tutorials/Enclosure+Ports/Tutorial%3A+Enclosure+Ports/287541 Their formula doesn't include end correction, but its easy to add it in. Also with their formula you know the area of the port, the length, and box volume and you are solving for the tuning. So you have to use it a little differently. "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:
Joe X Posted November 23, 2014 Report Posted November 23, 2014 If I end up with 33hz, I'm cool. I just don't wanna be above like 35. Thanks so much for your help! Btw, I looked, but I didn't find it. Can you link me to the formula on the JL website? That paper Triticum Agricolam has provided is all the accuracy you will ever need for daily projects, read it thoroughly, for inefficient port layouts you may likely experience slightly lower tuning than predicted. To be honest I see way more serious issues from what you comment up there so hope it turns out good for you.
user18436572 Posted November 23, 2014 Author Report Posted November 23, 2014 If I end up with 33hz, I'm cool. I just don't wanna be above like 35. Thanks so much for your help! Btw, I looked, but I didn't find it. Can you link me to the formula on the JL website? That paper Triticum Agricolam has provided is all the accuracy you will ever need for daily projects, read it thoroughly, for inefficient port layouts you may likely experience slightly lower tuning than predicted. To be honest I see way more serious issues from what you comment up there so hope it turns out good for you. What do you mean? And what paper?
Krakin Posted November 23, 2014 Report Posted November 23, 2014 Joe? Care to elaborate? This one: http://www.jlaudio.com/header/Support/Tutorials/Enclosure+Ports/Tutorial%3A+Enclosure+Ports/287541 Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener.
user18436572 Posted November 24, 2014 Author Report Posted November 24, 2014 Joe? Care to elaborate? This one: http://www.jlaudio.com/header/Support/Tutorials/Enclosure+Ports/Tutorial%3A+Enclosure+Ports/287541 OK. So, according to JL, you should subtract half the port width, not 2.227(Dv). That's a HUGE difference. JL's way, I would only subtract 2in. Not 18..Can someone please give me a straight answer on this? Also, I was more curious about what other more serious issues Joe was talking about.
Joe X Posted November 24, 2014 Report Posted November 24, 2014 Joe? Care to elaborate? This one: http://www.jlaudio.com/header/Support/Tutorials/Enclosure+Ports/Tutorial%3A+Enclosure+Ports/287541 OK. So, according to JL, you should subtract half the port width, not 2.227(Dv). That's a HUGE difference. JL's way, I would only subtract 2in. Not 18..Can someone please give me a straight answer on this? It doesn't say subtracting the end correction anywhere on that paper. You should use the tuning equation on the same paper also.
user18436572 Posted November 24, 2014 Author Report Posted November 24, 2014 Joe? Care to elaborate? This one: http://www.jlaudio.com/header/Support/Tutorials/Enclosure+Ports/Tutorial%3A+Enclosure+Ports/287541 OK. So, according to JL, you should subtract half the port width, not 2.227(Dv). That's a HUGE difference. JL's way, I would only subtract 2in. Not 18..Can someone please give me a straight answer on this? It doesn't say subtracting the end correction anywhere on that paper. You should use the tuning equation on the same paper also. It says that the effective length of the port is longer than the physical length by half of the width of the port. So, I would have to subtract half the port width in order to make my effective length accurate. No? I would prefer someone actually explain why one way is the correct way rather than just tell me to read something I already read that totally contradicts what someone else showed me. I created this thread to actually learn, not so someone can just tell me how to do something without explaining it to me. And I take it you don't want to answer my other question? You expressed that you had other concerns, but won't elaborate...
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