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View Full Version : t-line for sundown e8



tyler_fitz
07-25-2009, 03:31 PM
alright folks, so i read the tutorial about how to make a t-line over on smd, and i even designed a box based of the tutorial, but then i learned that his formula for making a t-line was uber simplified and dumbed down and there is a lot more that goes into a t-line than that...

so how do i design a t-line the right way? and before i go any further, this is not going into a vehicle, this is for my bedroom, its fairly large, about 240 square feet. its for music, not so much movies and video games (maybe sometimes...)

PBateman
07-25-2009, 03:57 PM
alright folks, so i read the tutorial about how to make a t-line over on smd, and i even designed a box based of the tutorial, but then i learned that his formula for making a t-line was uber simplified and dumbed down and there is a lot more that goes into a t-line than that...

so how do i design a t-line the right way? and before i go any further, this is not going into a vehicle, this is for my bedroom, its fairly large, about 240 square feet. its for music, not so much movies and video games (maybe sometimes...)

Where did you learn this? Did someone tell you that?

Miskin
07-25-2009, 04:01 PM
big bedroom

tyler_fitz
07-25-2009, 04:15 PM
Where did you learn this? Did someone tell you that?

is his method correct? not sure where exactly i read it...

PBateman
07-25-2009, 04:18 PM
Just build it!

tyler_fitz
07-25-2009, 04:22 PM
here we go,


If you think the math is easier, you must have built it according the steve meade forum tutorial, which says to use the Sd and Fs of the driver and go to town. This is not an accurate transmission line model and I would bet my life that if you measured your impedance curve you would have to distinct spikes (which means it's a 1/4 wave resonator and not a transmission line for that driver).

Looks good and I bet it sounds great though!

and...


wow that steave meade tutorial was fail then :crap: i dont think anyone should use it.

and then...


I've been saying that for a while. You can still get good results from it though so it's not a completely bad thing, just very misleading and uninformed.

It's kind of sad that people rag on PWK transmission line designs when he has a much better grasp of 1/4 wave resonators than that guy does.

tyler_fitz
07-31-2009, 06:51 PM
bump for a second opinioin

i guess immacomputers main beef with the t-line tutorial is that it doesnt account for cabin gain, but since this is going in a large room will that even matter?

Volenti
07-31-2009, 11:24 PM
You still get "cabin gain" in a room bit it's not as dramatic and at a far lower frequency than in a car.

Since you are looking at a design for home I suggest you check out this link http://www.diyaudio.com/forums/showthread.php?s=&threadid=97674 It's the "new hotness" when it comes to enclosure design, yes it's a horn, but the modeling software used will also model T-lines just as easily, there's no need for guesswork or rules of thumb in T-line/horn design anymore.