Ian Macfadgen

ok, so.. turns out my sub was wired to 4 ohms the whole time i had the old box and it was still overpowering the mids and highs lol. i didnt know my amp was even that powerful.. i thought it was just crappy. well anyway, i had to turn the gain half way because it makes a really awful port noise as if the box is about to just blow up lol. lower volumes sound just fine, but itll be good til i get the actual real thickness of board i need and put more time and love into it. thanks for the input guys.

well, maybe i didnt totally lose here. i have a pair of 8" jbl gt82's. im sure i could fit one in here, although it wont handle nearly enough power as id like. or not... so im just going to brace the shit out of this box and dump a whole bottle of glue in each crack and crevice and maybe some caulking and see how it goes lol. and/or, i could put some 'end caps' on each of the sides where it should be the least structurally sound. it would make the most sense in that case because the cap would be hitting every single piece of the box.

according to torres calculator, i could maybe extend the port width from 2 inches to 2.125 and it will somewhat fix the tuning. any thoughts before i actually go and make it? or am i over thinking this?

ok, so... with my great luck, i accidently picked up(and got it cut and everything) 1/2 inch MDF. is that going to greatly affect the inner dimensions or ability to put it together? because i already got a plan drawn out and it was planned out with 3/4 MDF. i didn't realize until i started drawing everything out for the cutouts. the dimensions are: front/back: 24x15.5 top/bottom: 24x14 sides: 14x14 and the port dimensions: p1: 12x14 p2: 9.5x14 should be 2 cubes at 35hz tuning its for a single SA-12 running at about 800 watts RMS power.

the hole doesnt go through the whole box, lol... its just like any other port, it ends before the end of the box.

i made my box in a way that wasnt very good and the side panels werent big enough so i decided to smother the cracks in tons of glue and caulk. im SURE it leaks air.

anywhere from around 30hz all the way to 60-80. i believe most songs are in the range of 30-50 for the main track. all i want is to broaden the range of what i already have. Then make a new box I'm guessing your useing a prefab its not a prefab, haha. it's a poorly made sealed box at 1.07cuft(after displacements). you'd laugh if you saw it haha. i already have a design for a new box for that sub to make it ported, but i don't have the cash right now.. so i don't know what to do. this 8" sub thing is just an idea for now. seems most people say it's a bad idea lol. i may as well just get another 12.

anywhere from around 30hz all the way to 60-80. i believe most songs are in the range of 30-50 for the main track. all i want is to broaden the range of what i already have.

i don't get it. i have two 8" oldschool jbl's. they definitely did put out a better 'high' bass. the 12 can hit the lows much better but when it comes time to hit a higher frequency, it doesn't seem to do it nearly as well as the 8's did.

hey guys, i have a single sundown sa-12. i had the idea of broadening the range of my bass(i listen to lots of dubstep and dnb) by adding a single or maybe two sa-8's. if i made a box for that, would they need to be in a separate space in the box? or could i just make two different sized holes and put them in a shared space and port? what do you think?

i'd like to make it as flat as possible. making it any higher than 1 cube will give it a tiny bump around 50hz. not like they're designed for spl anyway. they only have a 4mm xmax and i don't have the manufacturer's recommendations, nor can i find them anywhere. i feel like the t-line is just a no-go until i can get help from someone who's done it before.

pretty much making the box smaller or changing the size of the opening of the port will raise the tuning. problem is, the internal volume has to be as close to 1cu ft for this sub. i've changed the box size to be the correct tuning, but it changes the box's volume to around .5-.8cu ft. changing the size of the port will change the ports volume, and that has to be 30cu in. (didnt realize til i uploaded. the flat line is tuned to 44hz at 1cu ft. the more gradual one is set to how the box is now.)

(sort of) figured it out. problem is, it's tuned to 34 hz and this is just an 8" sub. putting it through winisd at 34 hz bows the line way down. its perfect at 44hz. changing the depth would change the tuning, but the box would be too small if i tuned it (that way) to 44 hz. changing the opening size would change the port area, so i don't know how to go about this. oh and i almost forgot that i didnt put any bracing in as well. hopefully im not just talking to myself here... but here's what i got H:40 W:10 D:15.5 port opening: 3.6x8.5 the line under the hole for the sub is where it starts at 72 inches overall port length in total, it should be .88 cubic ft tuned to 34.5hz

this is getting ridiculous. i have a basic design drawn out with the right port length, but as soon as i changed one tiny thing all the numbers were completely thrown off. i may as well just stick with the simple ported box. i understand it might not be the best, but at least it's not going to drive me crazy.

yeah, i just got done reading it. figured out the length and port area i need. port length should be 6ft, port area 30sq in, its fs is 47hz. i don't even know where to start. math was never my strong suite.

yeah, i was thinking about doing that. the one problem is all the crazy math and rules to go by. it would probably take me a week before i got a proper t-line design. they're so efficient, i could probably put it in an even bigger room and be fine if i needed to. the sub im using has a 100w rms, but the xmax is really low(4mm from what i've read). not sure if it would be so t-line friendly with a number that low.

in a home. itll be in a rather small room.

i have two 8" jbl gt82d subwoofers. now... i know they're designed for a car, but the whole idea is to recycle what i'm not going to use in the car to begin with. i'm not too sure about the port area, because these subs were made some time in the 90's, i believe. it'll also be running only on 25 watts rms. i designed an enclosure for a single sub. here's what i came up with. the port is 3" in diameter and is 7.5" long. itll be a pvc port. any ideas? or do you think it's alright to build. i don't want my materials to go to waste. always better to be sure before you start.

you did. people just can't read properly.

ok, cool. that cleared everything up. thanks for the design. the extra .25 cubes should be absolutely no problem. i had a 2 cube box with two 8's before i got this. fit kind of tight, but that's because i havent taken out the 'cup holder' in the back(if you'd even call it that... its way to shallow to act as a cup holder).

i'm not quite sure if i understand this. how did you figure out the port length? i put in torres calculator for the port: width 2, height 14 and length 21.5(i just added the two lengths(of the port cutouts) you gave me and it says its tuned to 40hz. then i tried another thing. taking 15.5-.75(minus the back wall)+9.5(extention)+2.75(port width plus width of board) and i got 27. that made the port tuned to 38 hz. call me stupid, but what's the problem here? is it my awful math or complete lack of knowledge on the subject? lol

this one should be rather simple. it's just going to be a single sundown sa-12 in a ported box. it's going in a small extended cab truck. it should be going on the passengers side in hope that i can get it to seem louder(or is that wrong?). i know the double baffle looks awful there. it was made after i made the port and i didnt want to do it all over again. the real thing will just have two pieces glued together. one question i have though. how am i going to extend the port length? it has to be 6.5" long and i can only find 6" long ones. dimensions should be 20.4LX14WX15.5H using 3/4 mdf. the port is going to be a 3" diameter 6.5" long aero port, so that should make it tuned to 35hz according to torres calculator. what are your thoughts? here's the model i drew up:

awesome! this is the type of information i was looking for. im trying to set it up for SQ anyway. i put some numbers through winisd. the ported box seems to do much much better on the low end. it's all about the loudness and efficiency. i couldn't care less about numbers that show up on an SPL test. spl does not equal loudness. oh, and would you happen to have a design drawn out on sketch up or solidworks or something similar? i'm interested in seeing the dimensions and where you placed the box. maybe a picture would be good enough, if possible. thanks -Ian

i'm extremely unhappy with the box i originally made and i want the best out of what i have. it's a sealed box at 1.08 cubes after displacement. it has all sorts of problems with it. major air leaks, weird proportions and the top piece had some pretty bad water damage, but i took my chances and it didn't work out so the screws are all messed up. so, i want to build another box from scratch. so what's the best way to go about this? i'm thinking maybe making a taller box with the sub facing up and having a port or two facing forward. i may use the lower volume of 1.50 instead of what everyone else says. i think their site just goes with the number in the middle of their two recommended volumes. i'm running an RE audio DTS1000.1 at 1 ohm. that should be ~800 watts. i still need to have at least one or two clicks back available for the drivers side seat, that's one requirement i have. some questions: -is it better for the sub to be facing upwards, backwards or forwards? -does it matter all that much which way the port(s) is(are) facing? SA-12 specs/site: http://sundownaudio.com/index.php/products/subwoofers/item/sa-series.html?category_id=2