J-Lane Posted August 5, 2020 Report Share Posted August 5, 2020 So a friend has two JL 12W3V3-4 subs. He wanted me to design a ported enclosure for him. Bass Box Pro says it would be best suited for a sealed enclosure. However he's dead set on going with a ported enclosure. After he gave me the maximum dimensions and looking at the recommended tuning and box volume from JL audio I have run into some issues. I was going to do a long slotted port facing the back of the vehicle (port running along one side and back of box) with the subs facing up but he want's the part of the box that faces the seat to be angled to match the seat. So I don't think I can do the slotted port the way I planned. I looked into Aero ports but they would have to be ridiculously long and have several bends in them and I heard that is not recommended with Aero ports. The last option I came up with would be to face the slotted port up with the sub's but to maintain the correct port area and tuning it's going to be super long and skinny (see photo). I'm concerned about performance. I know I'm probably over thinking this but it's driving my crazy! Does' anyone know if this port shape will greatly affect performance? Link to comment Share on other sites More sharing options...
fishchris1 Posted August 5, 2020 Report Share Posted August 5, 2020 18 hours ago, J-Lane said: So a friend has two JL 12W3V3-4 subs. He wanted me to design a ported enclosure for him. Bass Box Pro says it would be best suited for a sealed enclosure. However he's dead set on going with a ported enclosure. After he gave me the maximum dimensions and looking at the recommended tuning and box volume from JL audio I have run into some issues. I was going to do a long slotted port facing the back of the vehicle (port running along one side and back of box) with the subs facing up but he want's the part of the box that faces the seat to be angled to match the seat. So I don't think I can do the slotted port the way I planned. I looked into Aero ports but they would have to be ridiculously long and have several bends in them and I heard that is not recommended with Aero ports. The last option I came up with would be to face the slotted port up with the sub's but to maintain the correct port area and tuning it's going to be super long and skinny (see photo). I'm concerned about performance. I know I'm probably over thinking this but it's driving my crazy! Does' anyone know if this port shape will greatly affect performance? I'm not am expert on this, but I know a fair bit about ports.... In my personal opinion, a long narrow port will work, but probably won't be as efficient as a wider narrower one, because of increased surface area (drag on the air passing through it) If you just have no choice, I'd probably go about 10 or 15% larger to make up for this.... And of course it will need to be accordingly longer, as well to get you to the same tuning point. Link to comment Share on other sites More sharing options...
1point21gigawatts Posted August 5, 2020 Report Share Posted August 5, 2020 No where near wide enough and not enough port area. There would be port noise and the output would be affected. What kind of amp is going on them subwoofers? “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
fishchris1 Posted August 5, 2020 Report Share Posted August 5, 2020 2 hours ago, 1point21gigawatts said: No where near wide enough and not enough port area. There would be port noise and the output would be affected. What kind of amp is going on them subwoofers? Well, my answer was based on the assumption that the port area and port tuning were already figured correctly. Link to comment Share on other sites More sharing options...
1point21gigawatts Posted August 5, 2020 Report Share Posted August 5, 2020 4 minutes ago, fishchris1 said: Well, my answer was based on the assumption that the port area and port tuning were already figured correctly. No worries dude. It’s weird he just thanked us but didn’t respond. His buddy is gonna be pissed about that enclosure once he hears it lol! “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
J-Lane Posted August 5, 2020 Author Report Share Posted August 5, 2020 2 hours ago, 1point21gigawatts said: No where near wide enough and not enough port area. There would be port noise and the output would be affected. What kind of amp is going on them subwoofers? He said he's going to use a JL Audio Slash Series 1200/1v3. Your right on the port area. I swear I had checked that and now I'm looking at it wondering how the hell I missed that. Damn it! Back to the drawing board. Thank you for catching that. Link to comment Share on other sites More sharing options...
J-Lane Posted August 5, 2020 Author Report Share Posted August 5, 2020 3 minutes ago, 1point21gigawatts said: No worries dude. It’s weird he just thanked us but didn’t respond. His buddy is gonna be pissed about that enclosure once he hears it lol! I thanked you and was typing my reply. I wouldn't ask for advice and then turn around and build something you don't think would work. It took me a minute to reply because I was trying to figure out how I miscalculated the port area. Stupid mistake. Link to comment Share on other sites More sharing options...
1point21gigawatts Posted August 6, 2020 Report Share Posted August 6, 2020 13 minutes ago, J-Lane said: I thanked you and was typing my reply. I wouldn't ask for advice and then turn around and build something you don't think would work. It took me a minute to reply because I was trying to figure out how I miscalculated the port area. Stupid mistake. My bad dude. I jumped the gun and sounded crazy. But what is the net volume you are trying to yield on that enclosure build? I can help you on the port specs. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
J-Lane Posted August 6, 2020 Author Report Share Posted August 6, 2020 2 minutes ago, 1point21gigawatts said: My bad dude. I jumped the gun and sounded crazy. But what is the net volume you are trying to yield on that enclosure build? I can help you on the port specs. No worries! So I'm still not sure how I overlooked the port area. I know it's supposed to be 14-16 sq in per cubic foot. I was trying to keep the box volume close to JL's recommended 1.75 cu ft per sub (seems kinda big) and they recommend tuning to 30 Hz. My issue is his limitations on the max dimensions of the box. I think I'm gonna have to see if he can give me a few extra inches because increasing the height of the port to achieve the area I need is going to make the port even longer. Link to comment Share on other sites More sharing options...
1point21gigawatts Posted August 6, 2020 Report Share Posted August 6, 2020 16 minutes ago, J-Lane said: No worries! So I'm still not sure how I overlooked the port area. I know it's supposed to be 14-16 sq in per cubic foot. I was trying to keep the box volume close to JL's recommended 1.75 cu ft per sub (seems kinda big) and they recommend tuning to 30 Hz. My issue is his limitations on the max dimensions of the box. I think I'm gonna have to see if he can give me a few extra inches because increasing the height of the port to achieve the area I need is going to make the port even longer. The port isn’t gonna work in that location. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
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