T-line build help and advice

[Ryvin R Singh]

Hi there guys

Im from South Africa, and i think not many people here actually no about T-Line enclosures. I'v done alot of reading and trying to understand the method. it seems fairly simple, but the part that confuses me alot is the unit system.. so when its coming to the box design i am getting very confused with inches,squared inches and feet.. where as we work with millimeters,meters,cm or cm squared. add to the fact that i totally suck at math lol.

A colleague and i had built a trial t-line 15" sub box, it sounds great, iv never heard lows sounding so sweet before. But i want to build one for my new Sub exactly to its Fs.

Any advice and help on a single 15' inch t-line enclosure would help me alot My sub is a local brand sub called Targa..The subs are decent at a decent price. i'm saving up for a DD My subs specs are as follows :

Fs : 29hz

Spl : 90.4 dbs

Qts: 0.47

qes: 0.52

qms: 4.46

vas: 102.4Litres.

I realise the box might be massive.. i'v worked out my Line length to be - 9.75ft/2.9718mtrs and my coen area sq to be -
176 square inches (rounded off) am i correct? and how would i go about putting this on paper. perhaps somebody could help me out with a sketch ?

Thanks guys,

Any help will be much appreciated.

[Bradprobert]

To draw out a box you will need your max dimensions first. I would draw a 2 dimensional see-through box then put in your port area dimensions(same as cone area). for example if you can only go 21.5 in deep max and you need 200sq. in. of port, subtract wood displacement (in this example i will use 1.5) from the 21.5 to get 20in. deep for an internal port measurement. take your port area (200 sq in) and divide it by the 20 in you found earlier. that will give you 10in for your other port dimension. Your ports internal dimension is 20"x10".

Here is where that 2D figure will come in handy. put in your ports internal height of 10". (we dont need the depth right now). You can use this figure to find your line length

[Ryvin R Singh]

hey Brad

Thanks for the swift response..

i managed to take the tape measure and measure the space i have available, and im looking at Length - 39 inches, Breadth/depth - 26 inches and height of about 24 inches(could make it 26).. using your formulae i manged to get a port width and height of about 7.20" x 24" and after working out A and C i managed to come out with a port length( of about 91.8 inches.. does that sound near right?

i also wanted to know if the speed of sound formular matters in determining port length? ie 1130/fs(29)/4 which gave me a port length of 117inch?

[Pasta Prime]

i built one for a Skar 15 and my box was massive.

Heres the build if your interested:

http://www.youtube.com/watch?v=g5nlRsZsBJM