Zach Bruning Posted March 21, 2013 Report Share Posted March 21, 2013 What's up SMD forums? This is my first post and I was wondering if someone could check my T-Line design (also a first) and make sure the numbers add up. Thanks in advance guys. Link to comment Share on other sites More sharing options...
Krakin Posted March 21, 2013 Report Share Posted March 21, 2013 Your port looks a little big at 63 square inches. I would see about trying to make those turnes rounder just to make it easier for the air to flow. I would either wait to redesign till after you have your sub so that you can get the actual cone area measured from 1/2 of the surround to the center. Or try to find someone on here that has one to do it for you. I haven't checked your port length yet but just eyeballing it look okay. Edit: It's pretty hard for me to tell the port length with the dimensions given. If you could, could you check it yourself by drawing a line down the middle of the port from the beginning to the end and post the results. 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. Link to comment Share on other sites More sharing options...
Chris Hammer Posted March 21, 2013 Report Share Posted March 21, 2013 Havign the port area larger or smaller then the actual cone area changes the output. I know there is a more in depth explanation on here somewhere...but if my memory serves me right..IF...then the larger area will peak the output more while a lower port area will have a flatter response. How long is the port measured from center for the entire length? That would tell us your tuning. Also 45's or making your bends rounder can increase, or decrease you output...so don't think everything needs 45's. They are over rated IMO. Neither of my 1/4 tline builds used 45's. I tried them on my first one and actually removed them....it was Louder(by ear) without them. I won't use them anymore. Sundown list the cone area if I'm not mistaken..so go of that...Its more complicated to calculate exact surface area by measuring because you are not measuring surface area of a circle..you are measuring somehting cone shaped. MY BUILD *****http://tinyurl.com/gmcbuild***** Vehicles 2005 GMC Canyon CB1000r - Currently where any future funds are going. (exhasut,bazzaz, ohlins shock, screen, etc.) crf250r - Used to be race bike..now I just trail ride..practice at the track on it. CH80 - Daily beater (when nice weather)best 150$ ever spent. 100+mpg Sold to: Skullz - pstone11 - Leo1103 - Volvo 63' - pavelpardo - imnew59585 Shower farts still piss me off.I think theyre pretty neat. When the water runs down your crack as you let one out... its like shitting in a crockpot. Link to comment Share on other sites More sharing options...
Zach Bruning Posted March 23, 2013 Author Report Share Posted March 23, 2013 Sorry it took me a day or two to post back my weekend got started early. But i did some measuring and I think i got things figured out. Couldn't find the cone area of the E10 anywhere so I measured my sub with the tape running flat with the cone and from mid-surround to mid-surround i got 9 inches. Which gives me a cone area of 63.5 in squared. I ran a line down the center of my port in sketchup and i got a full length of 102.5 in. I think you are supposed to subtract 7-8 inches for the sub so that would give me like 95 in of port length. I'm tuning to the Fs of the sub which is 36 hz. Link to comment Share on other sites More sharing options...
matt scarlett Posted April 12, 2013 Report Share Posted April 12, 2013 1) A 1/4 wave transmission line doesn't have a "Port" it has a line width that is guided by a wave guide. Due to the size of the subwoofer, unless you go for a tapered t-line, the 'Line Terminus' has to be what it is. I'm currently running an SA-12 win a tapered t-line with a line terminus of around 4 " (if my memory serves me right without running to the car and checking). 2) 45's seems to be debatable at best. Some say to reduced corner turbulence, some say (in the case of t-lines) to keep the line constant. Zach Bruning, on 23 Mar 2013 - 20:12, said: in sketchup and i got a full length of 102.5 in. I think you are supposed to subtract 7-8 inches for the sub so that would give me like 95 in of port length. I'm tuning to the Fs of the sub which is 36 hz. 3) The reduction is to do with 'Boundary End-correction' and if the design is not optimised then around 5% should be good. On a personal note, I tune to what I want, not to the maunfactrers Fs figure. For good good measure, and because most of the true T/S parameters I’ve seen taken from enthusiasts, seem to be different to the manufacturers figures, and sometimes not by a small margin either I aim for around 5 Hz more than the prescribed Fs figure. Again on a personal and final note, I try and use a few-a-folds as possible. I tried similar output goals using a JBL GTO 804 sub. The more folds there were ... audibly, there was always something lacking. then to then on to Link to comment Share on other sites More sharing options...
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