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bunkerking09
11-13-2008, 10:54 AM
Can someone explain these to me?

I tried the search button, didn't get anything.

11-13-2008, 11:14 AM
Its essentially a long 'port' with an area = to cone area, and the length is = to the quarter wave length of the frequency you want it tuned to. There is no 'net volume' in the sense of a ported box, in a t-line, just 'port'.

If you need one designed, pm me for a quote.

bunkerking09
11-13-2008, 11:20 AM
how does the port area = the cone area? I think I understand the wavelength thing...but the other is throwing me for a lupe.

can it be used for a daily box and not just a burp box for a certain frequency? :confused:

slam
11-13-2008, 11:26 AM
The line area should equal or exceed slighty the cone area of the driver used. Normally, it is difficult to make the line area exactly equal to the cone area, as the frame and mounting immediately force an area larger than the cone area. The area can be gradually tapered down to the actual area to save space, but it can remain the same as when it started, as long as it is not more than than about 20-25&#37; more area. This means a very tight sizing for the woofer mount and the begining of the line.

11-13-2008, 11:27 AM
how does the port area = the cone area? I think I understand the wavelength thing...but the other is throwing me for a lupe.

can it be used for a daily box and not just a burp box for a certain frequency? :confused:

Lets say for example your cone area = 100 sq in. you'd then need the area of the t-line to = 100 sq in along the whole length of the line (like a port area of 100 sq in)

In terms of response, it will be affected by your car and your sub, but they have close to an 'ideal' bandpass response generally in terms of output. They are meant (typically) to extend an octave or so below tuning without the loss of output you see with regular ported boxes, as well as plenty above tuning, for a very flat response.

rollerdj
11-13-2008, 11:29 AM
please expain the quarter wave length a little more. That's got me a little perplexed. :crap:

11-13-2008, 11:34 AM
To tune it to a full wave length, you'd just use the length of a wave of that frequency. Divide that by 4 and you have your quarter wave length.

Immacomputer
11-13-2008, 09:26 PM
(Speed of sound in inches/second) / (4*Frequency in hz) = wavelength in inches

Transmission line enclosures do not always need to have the line area equal to the cone area nor does it always need to exceed it. This can work but is often not necessary. In order to find out how much line area you need, you need to consider the resistance factor of the driver, the shape function of the line (line taper and line frequency), the Sd, and the Re/(BL^2) product. That will give you an idea of how much line area would be optimal for the driver. Changing the line taper and line area will affect the frequency response and low frequency extension of the system. If the line area is too small for the mounting depth of the driver, it's possible to add a compression chamber for the speaker to fit.

Transmission line enclosures don't have to be as large as people think. I fit one in smaller dimensions than I fit a 2.2 cube ported enclosure. It had better efficiency; low frequency extension; power handling (mechanical power handling increased around 15-25hz); and transient response.

They are not going to be the best for getting loud at a single frequency but will offer a very musical and very efficient enclosure with a low end that is effortless and full. That is if the design is well implemented for the driver and vehicle.

wasted ink
11-13-2008, 10:15 PM

Immacomputer
11-13-2008, 10:19 PM
That's a bad tutorial.

IDSkoT
11-13-2008, 10:31 PM
That's a bad tutorial.

You should write one up. :D

p.s. where've you been?
You seem to be the only knowledgeable one in this whole site.

ahillworks
11-13-2008, 10:34 PM

Very Very nice! Good one. This should be typed up and posted in the stickies.

wasted ink
11-13-2008, 10:36 PM
That's a bad tutorial.

Write a better one then.

SVT03L
11-13-2008, 10:40 PM
Write a better one then.

Here is a better one quarter-wave.com

wasted ink
11-13-2008, 10:42 PM
problem solved :D

that is a good one

DDSC
11-15-2008, 04:03 PM
(Speed of sound in inches/second) / (4*Frequency in hz) = wavelength in inches

Transmission line enclosures do not always need to have the line area equal to the cone area nor does it always need to exceed it. This can work but is often not necessary. In order to find out how much line area you need, you need to consider the resistance factor of the driver, the shape function of the line (line taper and line frequency), the Sd, and the Re/(BL^2) product. That will give you an idea of how much line area would be optimal for the driver. Changing the line taper and line area will affect the frequency response and low frequency extension of the system. If the line area is too small for the mounting depth of the driver, it's possible to add a compression chamber for the speaker to fit.

Transmission line enclosures don't have to be as large as people think. I fit one in smaller dimensions than I fit a 2.2 cube ported enclosure. It had better efficiency; low frequency extension; power handling (mechanical power handling increased around 15-25hz); and transient response.

They are not going to be the best for getting loud at a single frequency but will offer a very musical and very efficient enclosure with a low end that is effortless and full. That is if the design is well implemented for the driver and vehicle.

Will it move gobbs of air:confused::crazy:

11-15-2008, 04:07 PM
Will it move gobbs of air:confused::crazy:

three gobbs to be exact

poundindak69
11-15-2008, 04:09 PM
three gobbs to be exact

i was hopein for 4 gobbs:crap:

11-15-2008, 04:11 PM
i was hopein for 4 gobbs:crap:

If you wire two in series you could have 6 gobbs :eek:

rollerdj
11-15-2008, 04:15 PM
overall, how much bigger are the t-line boxes vs a standard ported box? i might have to try one.

11-15-2008, 04:30 PM
overall, how much bigger are the t-line boxes vs a standard ported box? i might have to try one.

If you use the full cone area, quite a bit

rollerdj
11-15-2008, 04:32 PM
hummm. i was thinking about doing one for a single 10.

11-15-2008, 04:35 PM
hummm. i was thinking about doing one for a single 10.

that oem? I'm going to be building one for the same sub soon most likely

lets put it this way, for a single 10, at 30hz, the box will have over 3 cubes of internal airspace assuming you use the full cone area

rollerdj
11-15-2008, 04:38 PM
no, that one is for sale. i got a pair of SI baby mag's i might make a t-line for. but the most i really wanna do is 2.5 cubes and still try to keep room for other stuff.

twisztdauthorit
12-19-2008, 01:38 AM
Bringing an old thread back. ;)

Id like to learn more about how the compression chamber works, or atleast how to calculate it into the t-line if possible.

Im gonna go out on a ledge and try to design and build a t-line for an 18" sub. Obviously this wont be for a car. Tuning will be around 24 hz thinking of a tapered design about 1.2 - 0.5 or so.

Plan on using this sub
http://www.soundsolutionsaudio.com/zencart/index.php?main_page=product_info&cPath=2_18&products_id=56

Im stubborn and a DIY type of guy so please dont come to me offering ur services for \$... just yet

sinosic
12-19-2008, 02:44 AM
edit double post

sinosic
12-19-2008, 02:45 AM
That's a bad tutorial.

its not bad. its not the best but it works. i have made three different t-lines for 3 different subs and was surprised with all of them. they all got loud with about half the rms power. but i noticed that its was easy to push the sub to hard. also i used a eq to even the responce out. without the use of an eq all three had a noticable increase in output around the tuning of the line.

i think because of transfer function his tuturial does work.

mr. immacomputer im know you can design a better t-line than ken, ken is the guys name who wrote that tutorial. but kens method does work as long as the sub's qts and qms are with in range and you follow his directions well.