8" woofer enclosure size

[Akil]

I have been given a 8" woofer for free and I wanted to make a seiled box for it and I was wanting to know what is the best volume for a 8" sub.

I have doco from Rockford Fosgate which recomends a box with a volume of 8.5L/8500cm³

[TTriX]

i have a box design for one eight inch sub...but the only problem is that it barely fits into a pulsar/exa-hehe
box weighs in total 250lbs...but with just the front half of the box i hit 145 dbs at the windshield-with one 8" sub!!!
it was louder with both boxes using both waves of the speaker but i could not fit the whole thing into my car-hehe.
as for your box...trial and error, an 8 is small enough that you could build your own boxes and try different things and see what you like with out going through loads of materials.
T

[SupraBOY]

try something small like 10" X 10" X 8"deep for a sealed box.

for a ported maybe 14 X 10 X 9"deep. throw a 2" port in there bout 6" long if you don't want to be accurate and see how u go.

[Akil]

TTriX I would like to have a look at the plans/size for the huge box you are talking about. If I use the woofer it will not be going into an EXA.

I was going to play around with designs and different sizes as my Dad is a cabinetmaker and I can get all the materials for free! :D So all I was wanting was some suggested sizes.

[TTriX]

the box i used was horn theory on the front wave of the speaker and transmition line theory on the back wave of the speaker...i have a pic here somewhere and i will scan it tomorrow. i might even have the specific dimensions in my bible in the shop...it took me a weekend to do all the math on it then the next weekend to build it...then i put another night to figure out the tl part for the back box then another night to build the back box...it was definatly worth the pain in the ass!!!
i used it in my old place for a home audio sub and it shook the bricks on the house-hehe, the poor sub only had a .25" x-max too!!!
my buddy still has the box in his house as when i moved i had no room for it-hehe

but ya...gimme a day to look and load!
T
i designed one for a 15" sub but the box was so big i wouldnt be able to get it through the door-hehe-and it would weigh close to 1000 lbs ...like 9 sheets of 3/4 inch mdf!!!

[TTriX]

akil...
this ones for you-hehe
the hole at the bottom is where the speaker goes, it is mounted so it is firing into the box...
and wire it up as normal.
now the frequency responce was great except it had a significant roll off at 43 hz and down, peak frequency was 47 hz so when i built the transmition theory part of the box i set it up so it would have a peak frequency of 47 hz as well.
this second box that i built onto it also added the response curve to go down to about 23 hz...made a big improvement!
i am heading into the shop today so i'll check my bible for all the parameters...
T
ps...all my friends thought i was crazy when i hooked it up and it was loud as hell with just the front part...then all pissed up one night i said to everyone that i could get it louder and i did-hehe

and another thing...this box has to be corner loaded(the mouth/vent must be in the corner about 4" from the wall on either side for best results)

[Akil]

:eek: Oh S*@T!!! That is Huge! But I'm still interested in the exaxt sizes as I still might make it.

SupraBOY the sizes that you gave was that internal or external dimentions? If external is that with 18mm MDF?

[TTriX]

yup...that thing was huge-hehe
you should see it with the other box attached to it-hehe
i said it was close to 250lbs!!!
the wood i use is 3/4 inch mdf...i am not sure what it is in metric (funny us being canadian we still use the imperial measurements for construction-hehe)
one sheet of 3/4 mdf is about 108 lbs...there is a new wood made with wheat that is as equal as mdf- only half the weight, but it is also like three times the price-hehe
i was looking in my one book and found the specs on another box that is close to the same so it has all the dimentions on it...i'll scan it tomorrow and post it here.
T

[Akil]

TTrix thanks for that :)
Yah 3/4" MDF is the same as 18mm

[TTriX]

sorry akil...
i forgot to grab the bible out of the shop...i'll remember tomorrow-k?
T

[Akil]

That's cool. :}:

[TTriX]

aaaccckkk!!!!
someone took pages out of my bible!!!!
like tore them out!!!
akil...
there is not much left in there but i am going to go through it all and find some with the mighty 8 if there are any parts/pages left!!!
i found one with a t-line 10" and a t-line for three 8"'s but my baby's blue prints are missing!!!
look at the picture and try something or anything but it took me a whole weekend to figure out all the math in that box!!!
sometimes i hate people/theives!!!
T

[Akil]

Grrrrrrrrrrrrrrrr you gotta hate that!!!! :flamedevi :swearin:

Do you have any other designs for an 8" woofer?

[TTriX]

give me a day or two and i will draw and scan in the pics of one i will figure out...
do you happen to know the specs on that sub you got...ie.
Vas, Qts, Fs, Xmax, etc...or even possible kind of sub?
T

[Akil]

That would be cool... But only if you have the time hey. Don't want you to go to too much effort.

I have no info on it at all, the sticker on the back of the woofer was off when I got it. All I can tell you is that the material that the woofer is made of is yellow and that it has sections of blue felt on it.

I will see if I can take some pics of it if you want.

[TTriX]

pics would be coo!
and no problem mate, as i love playing around with the math-hehe
T
let me know what dimensions you have to work with as well or if you want it to fit the exa, as i think a t-line 8" would sound awesome loaded off the back
(a t-line box uses the back wave of the speaker to amplify the low frequencies with low port noise but lots of sound!)

[Akil]

I will see what I can do for pics. The woofer will be going in back of my Suzuki not an EXA. But the smaller the box the better.

[NVME]

lol... no wonder it was free...

but anyways, if you can't figure out what kinda sub it is :thumbsdow

you'll mostly likely have to stick it in a very small sealed box.

without any specs on the sub its gonna be pretty tuff designing any kinda of vented box for it.

good luck with it :heehee:

[Akil]

Grrrrrr, I lost the post where I had the pics of the woofer. Well here they are again has anyone got any idea what brand it is? ???