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Quarter Wave / T-Line tutorial-UPDATED


Forevrbumpn

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Quote...from the tutorial....from the first page..... "to have a true T-line, you need to keep the port/tunnel/line - a Line, that equals Cone area, or pretty close to it."

The tapering alters output and can actually increase it. Tapered lines are way over my head and the math that is involved but I hav e afeeling he gets the fundamentals and isn't just winging it on angle length etc. Tapered ones are out of my realm right now but something I want to try in the near future. I think they are considered a transmission line box still because they still involve calculating the quarter wave and stuff.

OR i could be totally wrong...wouldnt be the first time.

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Shower farts still piss me off.

I think theyre pretty neat. When the water runs down your crack as you let one out... its like shitting in a crockpot.
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sub PG R312D4

SD sub 500cm2

SD port constant 502 cm2

sintonized at Fs ~33hz

18mm mdf

The line would be better if it was the same depth all the way. If you scroll through here you can find some examples of what I mean. Hope it works out for you

it HAS the same depth and constant since the 1st 45 till the end of the port.

The line area should equal or exceed slighty the cone area of the driver used. Normally, it is difficult to make the line area exactly equal to the cone area, as the frame and mounting immediately force an area larger than the cone area. The area can be gradually tapered down to the actual area to save space, but it can remain the same as when it started, as long as it is not more than than about 20-25% more area. This means a very tight sizing for the woofer mount and the begining of the line.

http://www.t-linespeakers.org/design/classic.html

btw, thank you Eddie!

I just realized that i could do the normal desing since the depth of this line is a little larger than the actual magnet.

On my first attemp of t-line box (10 inch sub) i had this problem, the magnet depth of the sub was 12.5cm or so and the depth of the line was around 10cm, and i didn't wanted to waste extra space on the first division so i ended up using this kind of non-pure t-line desing xD

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Quote...from the tutorial....from the first page..... "to have a true T-line, you need to keep the port/tunnel/line - a Line, that equals Cone area, or pretty close to it."

The tapering alters output and can actually increase it. Tapered lines are way over my head and the math that is involved but I hav e afeeling he gets the fundamentals and isn't just winging it on angle length etc. Tapered ones are out of my realm right now but something I want to try in the near future. I think they are considered a transmission line box still because they still involve calculating the quarter wave and stuff.

OR i could be totally wrong...wouldnt be the first time.

Tapering the box (inward or out, depends on preferred acoustic outcome) does exactly that, increases the capability of the t-line for your preference. Some of the calculations end up looking very similar to a tapped horn.

The bog standard "i can build it" basic t-line is a symmetrical length of port built to your preferred resonant frequency. Where you go beyond that is your choice.

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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From my understanding, as long as the line doesn't get any THINNER than cone area, than it doesn't matter much, as long as it's not much wider. The thinnest part of the line is pretty much the bottleneck, and it will act as if that's the constant length.

*New vehicle and system coming soon.*

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Quote...from the tutorial....from the first page..... "to have a true T-line, you need to keep the port/tunnel/line - a Line, that equals Cone area, or pretty close to it."

The tapering alters output and can actually increase it. Tapered lines are way over my head and the math that is involved but I hav e afeeling he gets the fundamentals and isn't just winging it on angle length etc. Tapered ones are out of my realm right now but something I want to try in the near future. I think they are considered a transmission line box still because they still involve calculating the quarter wave and stuff.

OR i could be totally wrong...wouldnt be the first time.

Tapering the box (inward or out, depends on preferred acoustic outcome) does exactly that, increases the capability of the t-line for your preference. Some of the calculations end up looking very similar to a tapped horn.

The bog standard "i can build it" basic t-line is a symmetrical length of port built to your preferred resonant frequency. Where you go beyond that is your choice.

I've always been interested in tapped horns. Could you pm me maybe with a place I can go to read up on them. I think I want to try one for my little home audio 10" sub

MY BUILD *****http://tinyurl.com/gmcbuild*****

Vehicles

2005 GMC Canyon

CB1000r - Currently where any future funds are going. (exhasut,bazzaz, ohlins shock, screen, etc.)

crf250r - Used to be race bike..now I just trail ride..practice at the track on it.

CH80 - Daily beater (when nice weather)best 150$ ever spent. 100+mpg

Sold to:

Skullz - pstone11 - Leo1103 - Volvo 63' - pavelpardo - imnew59585

Shower farts still piss me off.

I think theyre pretty neat. When the water runs down your crack as you let one out... its like shitting in a crockpot.
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Best place is usually your favorite home theater based forum. I'd suggest Bill Fitz Maurice but he has this thing against any diaphragm exceeding 15" which makes it exceedingly hard to discuss horns there from time to time..

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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  • 2 weeks later...

So I think I've gotten my spec on a T-Line box for my Polk 8". My line will be 8' with a port area of 2.3ft^3. I have to go to Augusta Tomorrow so I'm going to pick up some MDF to supplement my stack in the shop just so I have extra if needed.

Here are my T/S Parameters as per the manual.

QTS:0.6

QMS:5.5

QES:0.7

VAS:15.40L

FS:35Hz

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