resko1 Posted October 14, 2010 Report Share Posted October 14, 2010 Well, I did some math, and a crapy drawing on paper. I can't do graphic design to save my life, just spent two hours trying to get the first straight port wall and couldn't get it the way it needed to be. But, my math - Box 31.5x31.5 x H 11.5 made out of .75 MDF Looked up cone area, and tens are roughly 78.54", but Foreverbumpin said 60, so I said ok, 70" of port. Port is 10" tall and 7" wide.I want it tuned to 30hz, so port needs to be 112.92 inches. (I think i ended up a little over or short, by no more than 5 inches I think. Would this work for an Re SEX? I can take a picture of my sketch if someone wants to help I'm not sure if I did the calculations correctly or if I did the port right, will the specs fit in a 31.5 X 31.5 X 11.5? On paper I think it looks good but I'm not sure if I did the wood displacements correctly. The way I have it is there is a big space in between the ending of the port and the sub, I planned to have the amp here. Also, in my design I didn't include 45 degree corners, I'm not sure if they are necessary? If so, my design is probably way off, I'm not sure. Sorry for writing so much. I could use some help I'm a Thank you very much, Joe To find the port area, take the sd from the ts parameters (effective cone diameter) and divide it by 2. then multiply it by itself and pi. example.. say for instance the sd of a 10" is 8.93(which it will be less but this is hypothetical) 8.93/2= 4.465 then you take... 4.465 X 4.465 X pi(3.1415)=125.259 so your port area would be around 125 sqin. Now take the fs of the sub. 26.6hz divide the fs by the speed of sound which is 1130ft per second. so... 1130/36.6= 30.874ft- that is your full wave. sound transfer is at its apex with the quarter wave so to get the quarter wave, divide that number by 4 so.. 30.874/4= 7.7185ft(or 92.622in)for the quarter wave. that is how long your port needs to be and MAINTAIN 125sq in at all times. That means you will need to 45 the corners. 04 Chrysler Sebring Stinger C&D Technologies Alpine Infinity/cdt Zapco TC Sounds custom subs Link to comment Share on other sites More sharing options...
Playa Named Joe Posted October 14, 2010 Report Share Posted October 14, 2010 To find the port area, take the sd from the ts parameters (effective cone diameter) and divide it by 2. then multiply it by itself and pi. example.. say for instance the sd of a 10" is 8.93(which it will be less but this is hypothetical) 8.93/2= 4.465 then you take... 4.465 X 4.465 X pi(3.1415)=125.259 so your port area would be around 125 sqin. Now take the fs of the sub. 26.6hz divide the fs by the speed of sound which is 1130ft per second. so... 1130/36.6= 30.874ft- that is your full wave. sound transfer is at its apex with the quarter wave so to get the quarter wave, divide that number by 4 so.. 30.874/4= 7.7185ft(or 92.622in)for the quarter wave. that is how long your port needs to be and MAINTAIN 125sq in at all times. That means you will need to 45 the corners. Wow, I don't know how i mess that up so bad. Thank you. The sub's SD (what does that stand for? Surface displacement?) is 310 ^2 cm which is 48^2 inch, You said it'd be smaller than 8.XX? 1994 Pontiac Grand Prix build Link to comment Share on other sites More sharing options...
resko1 Posted October 14, 2010 Report Share Posted October 14, 2010 Wow, I don't know how i mess that up so bad. Thank you. The sub's SD (what does that stand for? Surface displacement?) is 310 ^2 cm which is 48^2 inch, You said it'd be smaller than 8.XX? SD is the effective cone area or diameter. its a little under 8". see 8/2=4 4x4x3.1415=50.246 so your effective diameter is just under 8" so you would need to maintain 48sqin of port area the entire length of the port. I would advise against tunings other then your fs if your not seasoned at building t-lines and dealing with acoustical transfer. otherwise you can easily kill output and have nasty peaks. By tuning to the fs you should have a wide, flat bandwidth and great output. 04 Chrysler Sebring Stinger C&D Technologies Alpine Infinity/cdt Zapco TC Sounds custom subs Link to comment Share on other sites More sharing options...
Coleslaw Posted October 23, 2010 Report Share Posted October 23, 2010 SD is the effective cone area or diameter. its a little under 8". see 8/2=4 4x4x3.1415=50.246 so your effective diameter is just under 8" so you would need to maintain 48sqin of port area the entire length of the port. I would advise against tunings other then your fs if your not seasoned at building t-lines and dealing with acoustical transfer. otherwise you can easily kill output and have nasty peaks. By tuning to the fs you should have a wide, flat bandwidth and great output. Actually Sd is the Effective piston radiating area of driver. Not the diameter. When building a T-Line you want to port area to be the same as the Sd. If you don't know the Sd then you can calculate it by measuring from center of surround on one side to center of surround on the other side, dividing this by 2, squaring the result, and then multiplying by pi. I think you got some things confused. Link to comment Share on other sites More sharing options...
STEvil Posted October 25, 2010 Report Share Posted October 25, 2010 Actually Sd is the Effective piston radiating area of driver. Not the diameter. When building a T-Line you want to port area to be the same as the Sd. If you don't know the Sd then you can calculate it by measuring from center of surround on one side to center of surround on the other side, dividing this by 2, squaring the result, and then multiplying by pi. I think you got some things confused. uh... its a lot easier to just take the radius (4, half of the diameter) and punch that into A=TTr^2 3.14 x(4^2) = 50.24 MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..." Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through. Hammerdown... 1% no links to outside websites, business related FB/YT pages allowed. Link to comment Share on other sites More sharing options...
Playa Named Joe Posted October 26, 2010 Report Share Posted October 26, 2010 What would the result be if I had more port area then needed? Or less? 1994 Pontiac Grand Prix build Link to comment Share on other sites More sharing options...
STEvil Posted October 26, 2010 Report Share Posted October 26, 2010 Too much makes it more of a "free-air" enclosure meaning you need more excursion to make things happen, meaning you lose driver control and power handling capabilties (which are already low for a t-line). Too little just makes it noisier probably. You could make the throat tight like a horn (not too tight though) and flare the last couple feet out with little or no impact probably. MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..." Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through. Hammerdown... 1% no links to outside websites, business related FB/YT pages allowed. Link to comment Share on other sites More sharing options...
polkfan Posted November 2, 2010 Report Share Posted November 2, 2010 I would try my 16ov2 in a t-line but not sure on the spec.. Qts: .36 Qes: .42 Qms: 3.0 Qts and Qes should be ok but qms is kinda low.. Whats you think on that? Link to comment Share on other sites More sharing options...
BanginOnABudget Posted November 2, 2010 Report Share Posted November 2, 2010 Whats you think on that? i fuckin' lold. anyways, tlines are amazing. im taking out my passenger seat, battery is disconnected, going to unwire and take out the three amps, take out the 70+ lb box, then the platform so i can crimp 1 wire. Almost as bad as those fegs that put those horns in their grills and roll down the street distorting the block.... 1990 Jeep Cherokee 2 Dr. Big-3 in 0g on Stock Alt. Pioneer 6.5" and 5.25"s temp. until i can afford the new crescendos. Pioneer 6000ub Reciever NO amps at the moment. SA-15 on 1kw coming soon. MSG Me for a free enclosure design!! Flared port kits coming soon!! Link to comment Share on other sites More sharing options...
manofthehour Posted November 9, 2010 Report Share Posted November 9, 2010 i got a port opening of 6"x10" how do i figure the size of the 45s in the corners? My stuff '06 Scion xA: -Alpine iDa-x100 -Alpine KTP-445 Power Pack -Polk Audio db6501 (front components) -Polk Audio db651 (back coaxials) -2 RE Audio SEX12D4s -Cadence F1200-1D - Custom box tuned to 33Hz - Kinetik HC1400 - 50 ft2 of Audio Technix sound deadner - Big 3 My photography page Link to comment Share on other sites More sharing options...
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