KenSchoen Posted January 18, 2015 Report Share Posted January 18, 2015 On the following sight http://www.carstereo.com/help/Articles.cfm?id=31 I have entered various spec's for different subs. Something I noticed though is where you calculate the port length...simply changing it from a slot port to a square port but keeping the same dimensions make's it suggest a port thats substantially longer. Im hoping for an explanation on why this is Link to comment Share on other sites More sharing options...
Cj Kumz Posted January 18, 2015 Report Share Posted January 18, 2015 I'm sure it has got something to do with a slot port having common walls. Vw Polo Pioneer Deh-6050UB Sundown Saz-3500d DD Audio 9500 15'' 5.5 cubic feet box with 10 inch port @ 38hz I live to hear the Bass drop!!! Link to comment Share on other sites More sharing options...
alaskanzx5 Posted January 18, 2015 Report Share Posted January 18, 2015 The square port reduces net volume a good amount since it doesn't use already existing walls of the box. The reduced net volume means a longer port to achieve the same tuning. t1500bdcp 2 t2d4 15" 1 t600.4 1 t400.2 1 set p1 tweets singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz. Link to comment Share on other sites More sharing options...
Jeff4661 Posted January 18, 2015 Report Share Posted January 18, 2015 The square port reduces net volume a good amount since it doesn't use already existing walls of the box. The reduced net volume means a longer port to achieve the same tuning. Square port has less surface area than slot port. Less surface area = less air resistance It's a more efficient port Because of that. Heres a better example of what im talking About http://www.stevemeadedesigns.com/board/topic/189867-understanding-ports-a-lesson-in-dimensions-vs-efficiency/# Current build 05 Yukon SLT http://www.stevemeadedesigns.com/board/topic/195350-jeffs-05-yukong-wall-build/ Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 18, 2015 Report Share Posted January 18, 2015 It's what CJ Cums said, with that calculator when you select slot port you will get a shorter result since slot ports share common walls with the rest of box. This makes the slot perform likes its longer than it really is. What everyone else said above about square/slot ports is correct as well. "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: Link to comment Share on other sites More sharing options...
Joe X Posted January 18, 2015 Report Share Posted January 18, 2015 It's called the "End correction factor for slot ports" and JL Audio estimates it as Port Width / 2 (in reference to the pic below): The increased "effective length" of a slotted port is due to the common wall (in this case the back wall of the box) extends beyond the actual port length. The end result is that a slotted port will tune slightly lower than a non slotted one. Link to comment Share on other sites More sharing options...
KenSchoen Posted January 19, 2015 Author Report Share Posted January 19, 2015 The square port reduces net volume a good amount since it doesn't use already existing walls of the box. The reduced net volume means a longer port to achieve the same tuning. Square port has less surface area than slot port. Less surface area = less air resistance It's a more efficient port Because of that. Heres a better example of what im talking About http://www.stevemeadedesigns.com/board/topic/189867-understanding-ports-a-lesson-in-dimensions-vs-efficiency/# So based on going through that round port's are the most efficient. I knew that...but that present's me with a problem. The enclosure I have in mind and have been mulling over different drawing's and sketches...is that it seems to be a lot easier to fit a slot port or even a square port when space is an issue. Not how big the box can be space. Square footage on the face of the box space. Any suggestions? I want to design a box with the subs and port firing into the cabin. It's in my 2003 Honda Accord Coupe. I want designs layed out for multiple options. Three ten's, two twelve's, two fifteen's....but it sucks cause idk which subs I want yet. I was thinking P3's Link to comment Share on other sites More sharing options...
KenSchoen Posted January 19, 2015 Author Report Share Posted January 19, 2015 Also forgot to mention thank you all for the great input I really appreciate it! Link to comment Share on other sites More sharing options...
Joe X Posted January 19, 2015 Report Share Posted January 19, 2015 Not how big the box can be space. Square footage on the face of the box space. Any suggestions? I want to design a box with the subs and port firing into the cabin. It's in my 2003 Honda Accord Coupe. I want designs layed out for multiple options. Three ten's, two twelve's, two fifteen's....but it sucks cause idk which subs I want yet. I was thinking P3's Get the max box size you can build outside and get inside (you can get that building a cardboard dummy box and test fit), then you can answer most of your questions: 1) area of the baffle. 2) gross volume. From there you should choose a set of subs than can work in the space available and subs that you can afford, odd number of subs brings a problem and that is most of them you can't wire them to a final impedance of 1 ohm (usually), that means your amp can't deliver all of it's specified power or you will have to run it below stable impedance. Link to comment Share on other sites More sharing options...
KenSchoen Posted January 19, 2015 Author Report Share Posted January 19, 2015 Not how big the box can be space. Square footage on the face of the box space. Any suggestions? I want to design a box with the subs and port firing into the cabin. It's in my 2003 Honda Accord Coupe. I want designs layed out for multiple options. Three ten's, two twelve's, two fifteen's....but it sucks cause idk which subs I want yet. I was thinking P3's Get the max box size you can build outside and get inside (you can get that building a cardboard dummy box and test fit), then you can answer most of your questions: 1) area of the baffle. 2) gross volume. From there you should choose a set of subs than can work in the space available and subs that you can afford, odd number of subs brings a problem and that is most of them you can't wire them to a final impedance of 1 ohm (usually), that means your amp can't deliver all of it's specified power or you will have to run it below stable impedance. Yeah I know. Im referring to the process of laying out sub and port placement. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.