double check my t line math

[Jroo 10+ year member]

After looking at a bunch of t lines and forums, I thought I would try one. I found a site that had some simple math that I followed and want to know what you think. Mind you I am using a cheap

10" sub with Fs around 30hz.

For line lenght I followed this:

Speed of sound (1130 ft/sec) divided by subs Fs and then divided by 4 again. Gave me 9.4 feet

For port area I followed this:

pi x radius x radius. (middle of dustcap to middle of surround) My sub ended up being 5" roughly.

3.14 x 5 x 5= 78.5. So my port area would be 78.

So I would have a T line about 9 feet long or slightly shorter with a port of 78. This look right so far to you guys.

Click to read more...

 

[subzero 5,000+ posts]

Ask on Diyma. It prob is but ... I have a folded tline. friend drew up the plans for me.

 

[BlactimusCrime 10+ year member]

that sounds huge, just the port volume would be 5 cubes...

 

[Inferno333 10+ year member]

That's because it's a T-Line and not a vented enclosure.

113" is correct. The 78sq.in. seems wrong.

My 10" sub here has a radius of ~4. That gives you around 50sq.in. for the mouth.

I would use a 5.5"x9.5" mouth.

 

[Buck 5,000+ posts]

that sounds huge, just the port volume would be 5 cubes...

That's basically all a t-line is, it's a giant port.

Instead of using pir^2, why not use the Sd that the manufacturer gives you?

 

[sqoverspl 10+ year member]

The whole tuning to the fs and area=sd is wrong. It will work but not as good as it could be. That method more of a guess and not calculated.

 

[Jroo 10+ year member]

When you guys say use the SD, what is the math for that? I used this one becasue it was the one I saw most often.

 

[elancohen92 10+ year member]

How about you buy yourself a design from RAM?

 

[Buck 5,000+ posts]

When you guys say use the SD, what is the math for that? I used this one becasue it was the one I saw most often.

It's the actual cone area, given to you by the manufacturer. They calculate it.