Tline Tuning

[siucsaluki11]

So im lookin to see if i can get anything more outta my setup...Im currently runing 2 clarion PXW1251s in a 5 cube box tuned to 30 Hz. Im lookin at going to about 4.6-4 cubes tuned to 35 Hz, but i dont wanna loose my lows. So now im thinkin about a Tline. Only thing is, how low should i tune it? Tlines are new to me.

Subs specs that you may need to give me a bit of advice

FS: 30.76

Qms: 6.759

Qts: .545

Just not sure what to tune it to, it will be for 2 12s

[siucsaluki11]

So ive done some math, and layed it out on sketchup. Its gunna be a big box, but i can get 160 sq in of port and tune it to 36-40 Hz. Im wantin to give this a shot, see how it sounds. Next week i got pretty much nothin to do and i figure what better way to kill some time than tryin out a new enclosure right?

Edit for pics...

Edited June 26, 2009 by siucsaluki11

[Boon]

I'm not sure if it'll like having the subs at different lengths from the end of the line. T-Lines are all about phasing and you're introducing some dirty dirty phase inconsistencies by having them like that.

[siucsaluki11]

well, i can fix that, im takin off in a few to go shooting but ill work on it when i get back to the hotel.

[siucsaluki11]

is too much port area bad on a t-line? EX. say i have 160 IN of surface area between my 2 12s. (rounded number) and i got 180 in of port, cuz of design issues, is that a problem?

EDIT: So i got it at 192 in^2 if i stack them. Thats with leaving the port at 8" wide. I can cut it down to 7 but tat has to wait till tonight or tomorrow. That will put me back down at 160 in^2. Cant go narrower than 7 cuz the subs mounting depth is 6 1/4"

Edited June 26, 2009 by siucsaluki11

[SojiaRaggs9000]

Using math on the first page of the T-line thread you should have something like this:

( 1130 / freq ) / ¼ = ¼ wave length and ( Cone Area / 2 ) = ( X )² x 3.14 = X in²

SO....

( 1130 / 30.76 ) / ¼ = 12.245ft and ( 11 / 2 ) = (5.5)² x 3.14 = 94.985n² (90in² rounded)

SO you need to have 90n² of constant port with the port length totaling 12.245ft.

Of course all that math is just for one 12. If you can figure out the math and squeeze two 12's in the same port (which I doubt you can) Then you'll need

atleast 24in ~25in height internally and if you go with 25in tall then your width can only be 3.6. Because 25 x 3.6 = 90n² and 3.6 won't cut it unless your running some really shallow subs.

Not sure is if you can boost the 90n² to 180n² and run both subs in the same chamber. Might wanna ask forever bumpin about that.

But if you could then you're golden because 25in x 7.2in = 180n² and 7.2 is plenty of mounting room.

SO... you're port would need to be 25in tall x 7.2in wide x 12.245ft long.

Confirm that info tho.

~Kurk

Edited June 26, 2009 by SojiaRaggs9000

[siucsaluki11]

Using math on the first page of the T-line thread you should have something like this:

( 1130 / freq ) / ¼ = ¼ wave length and ( Cone Area / 2 ) = ( X )² x 3.14 = X in²

SO....

( 1130 / 30.76 ) / ¼ = 12.245ft and ( 11 / 2 ) = (5.5)² x 3.14 = 94.985n² (90in² rounded)

SO you need to have 90n² of constant port with the port length totaling 12.245ft.

Of course all that math is just for one 12. If you can figure out the math and squeeze two 12's in the same port (which I doubt you can) Then you'll need

atleast 24in ~25in height internally and if you go with 25in tall then your width can only be 3.6. Because 25 x 3.6 = 90n² and 3.6 won't cut it unless your running some really shallow subs.

Not sure is if you can boost the 90n² to 180n² and run both subs in the same chamber. Might wanna ask forever bumpin about that.

But if you could then you're golden because 25in x 7.2in = 180n² and 7.2 is plenty of mounting room.

SO... you're port would need to be 25in tall x 7.2in wide x 12.245ft long.

Confirm that info tho.

~Kurk

As i recall the port area needed to be equal to the total amount of surface area of the woofers. so using ur math, i need 180 in^2 of port. I was planning on tuning a bit higher than the subs FS cuz its so low. Even at 25 in i would need roughly 7" of port width.

Tuned to 33.2 Hz is only 8.4 ft for the 1/4 wave. I was going to run both subs same chamber, im pretty sure you can do that. I just need to make sure they are perfectly alligned. I may end up going subs and port up

Heres the old one modded a bit to fit the 2 12s. Only problem is that there is too much port area now. I could cut it down if need be.

Edited June 27, 2009 by siucsaluki11

[SojiaRaggs9000]

Im pretty sure if you build a t line you need to tune it to the subs FS... that's the whole point of the t line... When I built mine I built it to my FS which was 38. something and it got loud! The point of a t line is your building the perfect environment for the sub to play in.

[siucsaluki11]

and u need to check ur maths 1/4 wave for 30 Hz is just over 9 ft. Is it bad to tune it 5-6 Hz over the Fs?

[will77530]

Using math on the first page of the T-line thread you should have something like this:

( 1130 / freq ) / ¼ = ¼ wave length and ( Cone Area / 2 ) = ( X )² x 3.14 = X in²

SO....

( 1130 / 30.76 ) / ¼ = 12.245ft and ( 11 / 2 ) = (5.5)² x 3.14 = 94.985n² (90in² rounded)

SO you need to have 90n² of constant port with the port length totaling 12.245ft.

Of course all that math is just for one 12. If you can figure out the math and squeeze two 12's in the same port (which I doubt you can) Then you'll need

atleast 24in ~25in height internally and if you go with 25in tall then your width can only be 3.6. Because 25 x 3.6 = 90n² and 3.6 won't cut it unless your running some really shallow subs.

Not sure is if you can boost the 90n² to 180n² and run both subs in the same chamber. Might wanna ask forever bumpin about that.

But if you could then you're golden because 25in x 7.2in = 180n² and 7.2 is plenty of mounting room.

SO... you're port would need to be 25in tall x 7.2in wide x 12.245ft long.

Confirm that info tho.

~Kurk

dude how do you figure out the math is there like a formula you use i dont understand it could you please explain it to me thanks ~will