T line building

[Speedo]

How do you figure out the actual box size of a T line sub.

[3vil]

There is a rough formula on the T-Line/Quarter Wave thread, but it's mostly a starting point. It really involves building it then tweaking and testing to get the most out of a design.

[Tarball]

area of port = area of driver (SD)

length of port = 1/4 length of desired tuning frequency [.25(343/fs) result will be in meters using this formula]

ideal tuning frequency = Fs of the driver

round corners while keeping the port area constant for a standard t-line.

use good box building strategy - materials, glue, clamps, etc.

[Triticum Agricolam]

How do you figure out the actual box size of a T line sub.

Do you want it to sound decent, or do you just want to get loud? There is a lot more that goes into T-line design than some would like to believe.

[miniSPLlancer]

I always thought the idea of a T-Line enclosure was to be able to play a wide frequency while sounding generally clean.. Getting loud is easy, 10's, 12's, 15's, 18's, 2 of them, 4 of them, 8 of them.

[Triticum Agricolam]

T-lines can have a very wide frequency range and sound very clean, but its unlikely to get that kind of performance purely by chance or accident.

Really T-lines and ported boxes are very similar, they both do the same thing, they just do it in a different way. Just like how you can change how a ported box sounds by adjusting the net volume and tuning frequency, you can change how a t-line sounds by adjusting the line area/shape and tuning.

There is a problem with the common t-line design methodology of setting the line area equal to cone area and tuning to Fs. You are basing the design off of only two subwoofer attributes. There are lots of 12" (or 10", or 15" or 18") subs with a Fs in the low to mid 30s, but they are certainly not all the same and will have very different specs despite the fact they all have the same cone area and Fs. These different subs will all perform VERY differently if put in the same T-line design. This is why if you care about how the enclosure is going to sound you have to put more effort into the design and consider ALL the specifications of the sub/s you are going to be using.

Setting the line area equal to cone area is usually going result in a t-line that has a huge peak in output around the tuning frequency (small bandwidth) and has pretty low mechanical power handling. This is especially true with higher RMS rated subs since they usually have low Vas (tighter suspensions).

[meade916]

i will go ahead and move this to the proper area since you just randomly stuck in in the first place you saw without paying any attention. Normally i just delete. It's easier. Please pay attention next time, we have specific sections on this forum for a reason.

[Hugh G. Rection]

T-lines can have a very wide frequency range and sound very clean, but its unlikely to get that kind of performance purely by chance or accident.

Really T-lines and ported boxes are very similar, they both do the same thing, they just do it in a different way. Just like how you can change how a ported box sounds by adjusting the net volume and tuning frequency, you can change how a t-line sounds by adjusting the line area/shape and tuning.

There is a problem with the common t-line design methodology of setting the line area equal to cone area and tuning to Fs. You are basing the design off of only two subwoofer attributes. There are lots of 12" (or 10", or 15" or 18") subs with a Fs in the low to mid 30s, but they are certainly not all the same and will have very different specs despite the fact they all have the same cone area and Fs. These different subs will all perform VERY differently if put in the same T-line design. This is why if you care about how the enclosure is going to sound you have to put more effort into the design and consider ALL the specifications of the sub/s you are going to be using.

Setting the line area equal to cone area is usually going result in a t-line that has a huge peak in output around the tuning frequency (small bandwidth) and has pretty low mechanical power handling. This is especially true with higher RMS rated subs since they usually have low Vas (tighter suspensions).

Lots of good knowledge in the above post.

I like to think of PROPER t-line design as a decent primer course before entering into the world of horn loaded designing. It definitely teaches you alot about designing enclosures in general.

I have been a big fan if tapered t-lines for about 10 years, and they have numerous benefits over traditional aperiodic chamber ported type designs.