box design transmission line

[Rashaddd 5,000+ posts]

don't i calculate down the middle? i planned on putting in 45 degree wedges in the corners, but didn't know they shorten the actual length.

I'll illustrate it for you in a sec

 

[mokedaddy 5,000+ posts]

Oh jeese. Does everyone just through together a 1/4 wave and call it a t-line?

 

[Rashaddd 5,000+ posts]

Alright in this example, port length goes from 30 inches down the middle, to 28.25 inches down the middle

the labelled parts are the parts we are concerned with as they change when the middle of the corner changes

 

[azimuth 5,000+ posts]

Oh jeese. Does everyone just through together a 1/4 wave and call it a t-line?

that's why i posted it dipshit. never done one, so i started a discussion to learn more. what a tragedy. post something useful or avoid the thread.

 

[azimuth 5,000+ posts]

Alright in this example, port length goes from 30 inches down the middle, to 28.25 inches down the middle

the labelled parts are the parts we are concerned with as they change when the middle of the corner changes

that makes sense. it's the "shortest distance between 2 points" rule. thank you.

 

[nikhcePtcejorP 10+ year member]

Oh jeese. Does everyone just [b/]throw together a 1/4 wave and call it a t-line?

 

Fixed. Nice grammar Moke. You of all people.

 

Btw, are T-lines even popular in CA applications?

 

I just haven't heard much about em at all

 

[mokedaddy 5,000+ posts]

that's why i posted it dipshit. never done one, so i started a discussion to learn more. what a tragedy. post something useful or avoid the thread.

Dont get your panties in a wad, I wasnt talking to you.

It really should taper though as that will eliminate standing waves. Also what to you plan on using to dampen the sound waves inside the enclosure?

 

[mokedaddy 5,000+ posts]

http://audioweb.cz/down/a-non-resonant-loudspeaker-enclosure-design.pdf

Here is a very good read by the man credited with the discovery of the t-line.

 

[mokedaddy 5,000+ posts]

Fixed. Nice grammar Moke. You of all people.
Btw, are T-lines even popular in CA applications?

I just haven't heard much about em at all

Meh, it happens.

And honestly they really arent practical for most people in car audio due to high cabin gains, largeness of the enclosure, reflections... yada yada yada. I have seen and implemented quite a few with mixed success though. There are a lot of variables and you usually can get similar if not better results using a simpler design when all other things are considered.

Now give me a couple 18s in a large t-line for home audio, //content.invisioncic.com/y282845/emoticons/drool.gif.b5e863e893038027711d4402f340dad0.gif

 

[azimuth 5,000+ posts]

Dont get your panties in a wad, I wasnt talking to you.
It really should taper though as that will eliminate standing waves. Also what to you plan on using to dampen the sound waves inside the enclosure?

taper smaller or larger from the sub? i was just going to spray rubberized undercoating inside.

 

[azimuth 5,000+ posts]

Meh, it happens.
And honestly they really arent practical for most people in car audio due to high cabin gains, largeness of the enclosure, reflections... yada yada yada. I have seen and implemented quite a few with mixed success though. There are a lot of variables and you usually can get similar if not better results using a simpler design when all other things are considered.

Now give me a couple 18s in a large t-line for home audio, //content.invisioncic.com/y282845/emoticons/drool.gif.b5e863e893038027711d4402f340dad0.gif

i read the same about them being impractical, but i want to try anyway.

 

[mokedaddy 5,000+ posts]

taper smaller or larger from the sub? i was just going to spray rubberized undercoating inside.

I have a habit of going larger to smaller from sub to end of port, but as long as they arent exactly parallel it shouldnt matter. And I would definitely use some kind of acoustical stuffing at least one the walls.

i read the same about them being impractical, but i want to try anyway.

No harm in that. Like I said I have done quite a few over the years and even had one in my personal vehicle for a while.

 

[ContourSPL 10+ year member]

I've had mixed reviews on TL's. I'v read people saying that they don't have as much output as a ported enclosure and vice versa. At the same time, I've seen TL's with a compression chamber do 150 on the Termalb at 20 hz with four 10's. But when does a TL with a compression chamber differ from a ported enclosure with an extremely long port? Hell, anybody can make a ported enclosure with the port length a quarter wavelength of 20 hz I know that dB's don't necessarily mean much but we are talking about subwoofers hear //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Since I'm an SPL guy at heart, I like loud, peaky bass. I think maybe an expanding transmission line would be cool since they have a bigger hump in the frequency response. It would be nice to be able for someone to do an actual comparison with a ported enclosure and a TL in the same vehicle with actual results.

Good luck with venturing into your TL!