I recently aquired a brand new Sundown SA8v2. I talked with Thumper about a variation of an enclosure he built years ago for this sub, but after a lot of thinking, I wanted to do something original. Even though I have way more power than the 8 was designed to handle, I wanted to build a T-Line box. I built one years ago, and it sounded amazing. However, I didn't want to build just another boring rectangle t-line box that just looks like a ported box from the outside...

 

 

So... I present to you my variation of a t-line box I threw together this evening. It took a couple of days to design it, and I thought it was going to be a nightmare to build, but it actually went together in under an hour. All I have is the one picture, but the glue on the top and bottom are drying as I type this, so, if all goes well, I'll be finishing the box tomorrow morning, and have it playing by tomorrow afternoon...

 

 

Tell me what y'all think...

 

 

 

 

 

nice work.. bet that fucker is heavy!

oh what do you figure it to be tuned to?

It's not as big as it looks. It's only 26" in diameter. About 3/4 of a sheet of worth of wood. And It's "tuned" to the Fs of the sub, which is 34.7 hz. The line is 8.05 feet long.

Great craftsmanship!

 

 

But fuck that!

Really wasn't as bad as it looks. Only took about an hour to assemble. About halfway through I shot a nail into my finger. Luckily, it bounced off the bone and came right out...

Snail shell!

Very cool man. That should make a nice coffee table, especially if it had a plexi top.

No "tuning" with a T-line. 

 

What are you going to stuff with?

 Looks cool, btw...

Stuff with? Im putting just one SA8v2 in it. No polyfil. No need. I have the correct line length.

Stuffing it is the only way to adjust for flat impedance and decent response.  Unstuffed is the worst way to run a T-line, you loose all the non-resonant behavior a T-line provides, and that is the only advantage they have.

 

I have been building 1/4 wave T-lines since the early 90s...

 

Read Martin Kings white paper.

I'll have to put a pound of stuffing in the box before i.put the sub in.

Read the white paper, it will help you decide on the stuffing and how to properly install it.

And yes, don't finish the box until you finalize stuffing...

If you don't stuff, you are going to get 100% better performance out of a standard 4th order...  In all aspects...

Have a link to the white paper?

Was planning on building a 4th order next anyway. Haha.

If you don't stuff, you are going to get 100% better performance out of a standard 4th order...  In all aspects...

You just disrupted the fabric of truth that holds the internet together. The car audio world will never be the same.

I like different stuff and I like to see new people try stuff they've never attempted.

I've built plenty if just about everything. Doesn't mean I know much. Just because you do something for a while doesn't mean your doing it right. I'm sure this thread will turn into another pissing match but maybe it won't and maybe a few will help. I'll do my part others can add their helpful info too if they wish.

Per Vance Dickason (the way I interpreted it) states acoustic stuffing is to be used only in a transmission line after testing and to adjust system clue. Although not really sure how much that joker really knows. Or maybe I read wrong.

If your interested in a bit more of his teachings I recommend purchasing a copy of his "Loudspeaker Cookbook".

Was planning on building a 4th order next anyway. Haha.

By 4th order he meant a ported enclosure, not a 4th order bandpass

Ive always heard about the "woofer cookbook"... might pick up a copy. I'll probably just throw this box in, test, add some polyfil, test, and so on. But, this is going in a softtop jeep... Not like im striving for SQ here... almost all T-Lines i see have no form of filler. So does that mean everyone is doing it wrong?

Most of the t-lines you see on car audio forums aren't truly t-lines and most of those people also have no idea why they would even want a t-line compared to a more standard enclosure.

So the short answer is yes, most people in this hobby do it wrong.

The box looks great!

The white paper, I think? It's just what I found while using Google.

 

http://www.quarter-wave.com/OBs/OB_Design.pdf