Ian Macfadgen Posted July 15, 2012 Report Share Posted July 15, 2012 i have two 8" jbl gt82d subwoofers. now... i know they're designed for a car, but the whole idea is to recycle what i'm not going to use in the car to begin with. i'm not too sure about the port area, because these subs were made some time in the 90's, i believe. it'll also be running only on 25 watts rms. i designed an enclosure for a single sub. here's what i came up with. the port is 3" in diameter and is 7.5" long. itll be a pvc port. any ideas? or do you think it's alright to build. i don't want my materials to go to waste. always better to be sure before you start. Quote Link to comment Share on other sites More sharing options...
bassface Posted July 15, 2012 Report Share Posted July 15, 2012 So are you going to be using these in a car or in a home? Quote Link to comment Share on other sites More sharing options...
Ian Macfadgen Posted July 15, 2012 Author Report Share Posted July 15, 2012 So are you going to be using these in a car or in a home? in a home. itll be in a rather small room. Quote Link to comment Share on other sites More sharing options...
bassface Posted July 15, 2012 Report Share Posted July 15, 2012 If it was in a home i would be tempted to build a t-line. Quote Link to comment Share on other sites More sharing options...
Ian Macfadgen Posted July 15, 2012 Author Report Share Posted July 15, 2012 If it was in a home i would be tempted to build a t-line. yeah, i was thinking about doing that. the one problem is all the crazy math and rules to go by. it would probably take me a week before i got a proper t-line design. they're so efficient, i could probably put it in an even bigger room and be fine if i needed to. the sub im using has a 100w rms, but the xmax is really low(4mm from what i've read). not sure if it would be so t-line friendly with a number that low. Quote Link to comment Share on other sites More sharing options...
bassface Posted July 15, 2012 Report Share Posted July 15, 2012 Have you read the sticky on t-lines?http://www.stevemeadedesigns.com/board/topic/1828-quarter-wave-t-line-tutorial-updated/ Quote Link to comment Share on other sites More sharing options...
Ian Macfadgen Posted July 15, 2012 Author Report Share Posted July 15, 2012 yeah, i just got done reading it. figured out the length and port area i need. port length should be 6ft, port area 30sq in, its fs is 47hz. i don't even know where to start. math was never my strong suite. Quote Link to comment Share on other sites More sharing options...
Ian Macfadgen Posted July 15, 2012 Author Report Share Posted July 15, 2012 this is getting ridiculous. i have a basic design drawn out with the right port length, but as soon as i changed one tiny thing all the numbers were completely thrown off. i may as well just stick with the simple ported box. i understand it might not be the best, but at least it's not going to drive me crazy. Quote Link to comment Share on other sites More sharing options...
Ian Macfadgen Posted July 15, 2012 Author Report Share Posted July 15, 2012 (sort of) figured it out. problem is, it's tuned to 34 hz and this is just an 8" sub. putting it through winisd at 34 hz bows the line way down. its perfect at 44hz. changing the depth would change the tuning, but the box would be too small if i tuned it (that way) to 44 hz. changing the opening size would change the port area, so i don't know how to go about this. oh and i almost forgot that i didnt put any bracing in as well. hopefully im not just talking to myself here... but here's what i got H:40 W:10 D:15.5 port opening: 3.6x8.5 the line under the hole for the sub is where it starts at 72 inches overall port length in total, it should be .88 cubic ft tuned to 34.5hz Quote Link to comment Share on other sites More sharing options...
bassface Posted July 15, 2012 Report Share Posted July 15, 2012 If you made the port shorter it would raise the tuning right? Quote Link to comment Share on other sites More sharing options...
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