destroyer in a t-line

[MACnonsence6]

k guys so i have a pair of re destroyers with soft parts from tantric rated for 3.5-4k rms ea. murphy said 2-2.5 cu ea tuned to 30s with 14sq per ft of port. not i was able to get that with tores. with my max dementions being 32w17h28d so with those specs i was able to fit the pair of destroyers tuned to 33 with a net of 4.63 so just about right. and thats after woofer and baffle displacement. for bracing i planed to use full thread rods so id didnt acount for that as i dont think it would take to much space.

but then i actually sat down on this t-line section we have and pondered the idea of just running one destroyer. the reason being is after trying to figure electrical. im gonna have to cut out my spare tire well and build a battery bank to hold 6-100ah batteries to be able to even think about feeding an amp to feed those. im just not good with mapping things out so im wondering if someone can help me i did the math.

in order to have my destroyer in a 1/4 wave t-line tuned to 30hz i would need 9.14 ft of port and then my cone area would be 78sq in. now i tried to see if i could map that type of enclosure out in torres. just to get an idea if i could fit what i need in my dementions. the other issue i run into is the destroyers displacement. its pretty large .56 cu feet. i guess im asking opinions as to the cost of trying to feed 2 oposed to the output of one in a t-line.

i currently already haev a rf t20001bd just needs repairs. and my destroyers are d2 so a t-line oposed to having to get batteries, larger amp alt ect,

so those that are skilled in sketch do i have enough space to do a t-line for 1 destroyer ? with both woofer and port firing in the same area as this is a trunk car

[bbeljefe]

You won't be able to get a line in that space unless you taper it to about 60% of the sub's Sd and even then it will be tight. You might be able to make a snail shell line and have the terminus load to the back of the trunk, with the sub facing up, like this:

As for the output of a line... you won't be disappointed.

[MACnonsence6]

the only issue with the snail is its a small trunk car 98 neon. so that wouldnt work. i read about adding polyfill so the t-line doesnt need to be as long. im having issues trying to draw it out on paper.

pretty crazy that i got enough room for 2 of them in a ported but not enough for 1 in a t-line lol.

how do you calculate exactly how large the port is wxh. is it as simple as it can be anything as long as the total is 78 sq in of port and 9 ft long. perhaps if i tune to 40 and then poly fill. a 40 hz t-line should be able to dig into the 20s accuratly though correct esspecially with this driver

@ 40 hz tuning i would only need 7ft of lengh vs 9 but my original concern is still there

[bbeljefe]

As long as you keep the ratio of height to width less than 8:1 you can make the line any dimension you like. You can also build a loading chamber for the sub that reduces down to the proper line area and you can taper the line to about 60% of driver Sd.

I don't recommend tuning high and trying to fill the line, as the stuffing won't change tuning any appreciable amount. And for sure, don't tune above driver Fs because the sub won't have anything to control excursion. I've done a few at high Fs that matched the driver(s) and they did not perform well below tuning. One was for a pair of 6.5" subs and the other was for a custom built 12. They were loud as hell at and above tuning but low end response fell off rather quickly. It's possible that tapering the line would have corrected that to some degree but I doubt it would make enough of a difference to make it worthwhile.

All in all, I've had the best experience with tuning 5Hz or more below driver Fs and reducing the line area. Personally, I haven't reduced line area more than 20% but I have talked with a builder who's had a lot of success reducing by as much as 40%, which is why I suggested tapering to .6 of Sd.

[MACnonsence6]

i could reverce mount the woofer eliminating the need for the extra chamber but then everyones gonna see that huge ass motor. so you think i would be better off staying at the 30 hz tuning point of 9ft and then using 60% of my 78 sqin of port area?

my problem im having is im unable to grasp how to draw what your saying out within my dementions. so its hard for me to understand with out seeing it.

[bbeljefe]

Inverting the sub really won't help you if you plan to put it on top because you still have to have enough surface area for it to mount.

And yeah, I think you'd be better of at 30Hz but I don't know the Fs of your sub. If it's below ~38Hz, then tuning to Fs would be an option although it wouldn't save you a huge amount of length going from 30 to say, 35.

As for the drawing thing, I can't really help much because I don't use Sketchup... I'm an old man who uses pencil and paper or just works from what I see in my mind.

[MACnonsence6]

thats what ive been trying to use as well. and idk the fs being i built these with recones from tantric. im gonna read up draw some stuff out and see what you think. being its a trunk build i need both the sub and port to be firing forward. inverting it would make the taper easier to do

[bbeljefe]

Usually in a trunk you get better sound from sub/port back or sub up/port back. Or even sub up/port side. But whatever you decide, I'll be more than happy to look at it for you.

[MACnonsence6]

ya but then you have the issue of deck ratle and then interference with the 6x9s. thats why with my se's i did sealed firing in. sounded way better and was able to dig wicked deep into the lows.

[MACnonsence6]

had someone post this on caco

http://i1230.photobucket.com/albums/ee500/JarrodKitson/Macseven6_zpse4a83720.png

then reverse mount because of the size of motor and such. whats your thoughts here. 9.8' long port