Jump to content
Second Skin Audio

Quarter Wave / T-Line tutorial-UPDATED


Forevrbumpn

Recommended Posts

I still don't understand how all this works. I thought it was cone area = port area, port length tuned to fs of the sub. Apparently there's way more to it :shok:

There is not a wrong with making a T-line with the line area = cone area, and tuning to the Fs of the sub, there are just other ways to do it too. By varying the line area, length, a taper you can control how the T-line will sound. Much like how you can change how a ported box sounds by adjusting the internal volume and tuning.

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

Link to comment
Share on other sites

I still don't understand how all this works. I thought it was cone area = port area, port length tuned to fs of the sub. Apparently there's way more to it :shok:

There is not a wrong with making a T-line with the line area = cone area, and tuning to the Fs of the sub, there are just other ways to do it too. By varying the line area, length, a taper you can control how the T-line will sound. Much like how you can change how a ported box sounds by adjusting the internal volume and tuning.

Could you explain more to me or maybe PM? I'm planning on building one for my home surround sound just to try out.

Link to comment
Share on other sites

  • 3 weeks later...
  • 4 weeks later...
  • 2 months later...

https://transmissionlinedesigns.wordpress.com/

I don't claim to be an expert on t-lines, I built my first t-line back in 1991 and I haven't got it all figured out. I just built that site (link above) because I'm a bit OCD about t-lines. I've never put 100% faith into free software, and I design for fun. However, for me there's a degree of trial and error.

I don't by any means think that t-lines are the be-all and end-all of a good sounding substage, however it seems that of my friends who work in acoustics, they seem to hands down recommend t-lines (don't shoot the messenger), especially over ported enclosures (mostly talking about home audio applications here).

As for working out a design based around SD, FS etc, for me that's a bit of a misnomer. It's 'a' place to start, but certainly not the be all to t-line design. As for FS I design for a desired response curve. Yes I could search out the exact sub that has an FS of 30 or 43 or 28 Hz, but I'd rather build around my needs, and use a half decent quality subwoofer. There are some, especially in home audio, who buy a $6 sub from part-express closeout sales and tries and do something wonderful with it. Though it's fun, I wouldn't suggest doing that in this SMD forum. I'd rather buy a good sub, with an FS that isn't too high, then go from there.

Link to comment
Share on other sites

  • 2 weeks later...

So nobody has built one where the subs depth is deeper then the line dimensions should be ?

You can always reverse mount the sub if you run into that situation.

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

Link to comment
Share on other sites

Your line depth is going to be measured in feet for a subwoofer t-line, unless your tuning at something like 1hz. So how is your speaker mounting depth an issue? Just resign your folds to accommodate

He is referring to line DEPTH not line LENGTH. If he is designing a T-line for 10" sub and sets the line area = cone area its going to have a line area of around 55 sq in. Make the line 10" wide and its only going to be 5.5" deep. So with 3/4" material that gives you a max depth of 6.25", there are plenty of subs with mounting depths deeper than that.

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Who's Online   0 Members, 0 Anonymous, 817 Guests (See full list)

    • There are no registered users currently online
×
×
  • Create New...