Folded horn enclosure

[revoracing247]

hey guys, i was just wondering if anyone's heard anything (good or bad) on using an expanding TL design (folded horn) in a car. i really wanna try messing around with designs on a sub i have but i've heard from somewhere that folded horns in cars don't work well and it'd be nice to get peoples opinions before i spend the money on wood.

any input is welcome!

[Pink Noise]

i personally prefer a regular slot ported or aeroported enclosure

[DubNBass]

t-line in a truck?? hmm, would it even fit?

[the_garynator]

problem is, to make a folded horn big enough to have a reasonable benefit, it's either got to be tuned unreasonably high, or it's going to
be too small to make much of a benefit. I did some calculations to build a folded horn for a 15in sub with a reasonable gain and the mouth
opening needed to be something like 4ftx6ft or something ridiculous like that. It can be done, but you need a lot of room or it won't have much of a benefit over other enclosure options.

[rocking.that.eclipse]

Can someone educate me what a folded horn encloser is?

[the_garynator]

I have been toying with the idea of messing around with a folded horn for something to play with until I get my level 6s, so keep an eye out. I'll be using Martin Kings mathcad sheets for the design, so I'll see what I can come up with.

[the_garynator]

Can someone educate me what a folded horn encloser is?

decent basic rundown of what it is: http://www.newton.dep.anl.gov/askasci/eng99/eng99594.htm

Some in depth reading: http://www.diyaudio.com/forums/subwoofers/97674-collaborative-tapped-horn-project.html

[rocking.that.eclipse]

So the port gets wider the farther you are away from the sub?

Thanks for the pic also

[the_garynator]

So the port gets wider the farther you are away from the sub?

Thanks for the pic also

Basically.

Folded horns are based on quarter wave transmission line theory, there are also calculations to determine the throat area and mouth (opening), this determines the rate at which the line expands

[revoracing247]

yeah basically in a TL you can either have no change in port area or have it decrease or expand (horn). and i know tl can be big. i have a 24Hz t-line that the port area doesn't change for my JL 12" right now and it takes up all the extended cab part of my truck.

the sub im toying around with the idea of building a folded horn for is my 12"s baby brother. its an 8" sub same model and it's fs is around 30 Hz.

i've done some reading and what not today and one person on youtube said " If the point of a horn is to be an acoustic coupling device to match he sound waves with the environment, doesn't a horn loaded enclosure become a problem in a high SPL vehicle application?"

can someone help me understand the "coupling device" part of this.

and thanks for your guy's input so far!