Did I design this Tline correctly?

[galacticmonkey 5,000+ posts]

I did a quick read on 1/4 wave Tline design, and was wondering if I got it right. Heres a design I did for one of the cheap Elemental Design 12s. It has an F2 of 25hz I was told. So would this work? Throat length of 11.3' and a Throad width of 8"?

Click to read more...

 

[Immacomputer 10+ year member]

If you just did the 1/4 wave of 25hz and made that the line length and the line area the Sd of the driver then no, you did not design it correctly.

 

[galacticmonkey 5,000+ posts]

Well what is wrong about that? And how would I go about designing it correctly?

 

[Death By Bass 10+ year member]

it would work, but that box is huge!

 

[Immacomputer 10+ year member]

Well what is wrong about that? And how would I go about designing it correctly?

http://www.quarter-wave.com/

 

[goodstuff 10+ year member]

http://www.quarter-wave.com/

Wow. I wish I was better at math.

 

[Volenti 10+ year member]

It depends on what you want it to do, just eyeballing the enclosure it'll "work" as in it'll make bass, probably more suited to HT use in a room than for in a car (it may sound a little bloated in car and lack upper bass punch) , for car use I'd shorten it up some, look at 7'-8' line length with that same line area or even a little larger, 1.2-1.3x driver SD, that'll give you a little more gain.

TL's are dramatically effected by loading in a car so you can get away with a shorter line length than the calcs/theory would suggest.

 

[Immacomputer 10+ year member]

And, the line length is not based on the driver's free air resonance but rather its point of resonance in a sealed enclosure of the same size. That will almost be higher than free-air and will never be lower.

 

[Megalomaniac 5,000+ posts]

If you just did the 1/4 wave of 25hz and made that the line length and the line area the Sd of the driver then no, you did not design it correctly.

I am going to take a wild guess and say he saw the overgeneralized- tutorial on meades site.

 

[twisztdauthorit 10+ year member]

I'snt the throat supposed to be taperd down ? Or it this only on some designs to cancel out standing waves?

I created a t-line for one of my 10's (fs 25 or 28) i believe. Anyways it hits a hell lot lower then the prefab it came in... definitely a different sound.

 

[BrianChia 10+ year member]

http://www.quarter-wave.com/

Did you buy King's worksheets?

 

[Volenti 10+ year member]

I'snt the throat supposed to be taperd down ? Or it this only on some designs to cancel out standing waves?
.

You can taper it down, that can help smooth the response and decrease the length of the line you need, but at cost of output, an untapered line will have a higher output, you see all this when you start to use Martin Kings Mathcad software and model different designs.

For the most part standing waves aren't a big issue for bass TL's, especially car ones, most of our output happens below 100hz or so, the standing wave ripples are above that so with a decent low pass filter you won't hear them.

 

[80INCHES 5,000+ posts]

If you just did the 1/4 wave of 25hz and made that the line length and the line area the Sd of the driver then no, you did not design it correctly.

i agree and to add..its not taperd

but it looks like a killer ported box though

80

 

[galacticmonkey 5,000+ posts]

Oh, well I designed this to be used as a box for my room, with about 75-100rms. Just as something to test out and mess around with. Anyone know of any good designs that work well for HT? I say HT, but it will only see music if built.

 

[ballstothewall 10+ year member]

The cross sectional area needs to be 1.5 to 2 times the Sd