building sub box

[brendon]

I have to do a project for school and I wanted to do a simple sub box. Does anyone know where I can find sub box plans for a simple box that will fit in our trunks? Thanks any help would be appreciated.

[973000GTSL]

It's not that hard to build a basic box to fit in the back. First select which subs you want to use and find out the cubic air space required for the sub. Once you have that, building a box is easy. Lets say you are using a 10" woofer that requires .75cuft. lets say the only height spec is 12" tall or under. You use 1/2 mdf to build the box. So the OUTTER dim. are 12"X12"X8" the inside airspace would be 11"X11"X7" due to the 1/2mdf that would be 968cuin or .56cuft so you need to increase one dimension to increase the air space. Just run the inside dim. numbers till you are within the suggested space and add the thickness of the wood to the inner and you have your box. One think else to remember is that you can stuff the box to "trick" the sub that there is more airspace in a smaller box. Hope this helps. There are also programs you can get that will ask for the air space you want and a basic shape of the box and it will give you all your cuts to cut out the thinking.

[axispiral]

if its just a simple sub box, yea, but if you want a good functional one . . . get out your calculator

i made mine a long time ago, but as i recall it takes some work and nuts calculations to make it sound good.

some tips:
pick the sub you are making the box for, look for mounting hole diameter and mounting depth, then look if the sub should be in a ported or sealed box. most sound louder and deeper in ported box, but the sealed boxes sound cleaner and more crisp, just not as loud.

read the size recommendations for the sub, whether it be sealed or ported and then figure that into the construction of the box. when calculating for interior volume of the box make sure you take into account the size of your materials and the displacement of the sub. make sure everything is AIRTIGHT, very important and use good materials like 1/2 or 3/4 MDF, medium density fiberboard. do go cheap and get particle board, that is weak will crack and has imperfections, and please don't use plywood. use LOTS of wood glue and put in on at every wood to wood connection. its easy to clean up so feel free to put more than enough, just don't skimp. Also, along the inside of the box, along the seams, I used silicone sealant, just to be safe and make sure there are no leaks. Also, have lots of wood screws, there is no problem of using too many, just make sure they are on the middle of the wood when you drill, and make sure to drill pilot holes, so you don't split your wood. MDF is a little pricey compared to particle board or plywood, but its the best.

if your sub wants to be in a ported enclosure, then have fun with that, then you have to deal will port length and volume, then opening size and tuning the box to a certain Hz. you can look at the Theill Snell parameters of the sub to find all the important specs to know when constructing the box.

If you don't have a sub that you are building the box for there are some generic box designs and ports set-ups that i bet you can find online, but the trunk in our cars is short, so make sure you take that into account, i doubt that you will be able to fit a 12" standing up in the trunk, i have an RE SX 10" in mine in a ported box, more than enough for the car. since the car is a hatch it will resonate quite well. Remember that if you are getting a 10" sub the hole will be smaller than 10 inches, but you want to make sure that there will be enough wood on the top and bottom of the sub so that you will have room to mount the sub to the wood without worrying about splitting the wood.

what else . . . . . . hmmmmm

you want the sub to be facing backwards, cause in that way, there are more walls for the sound to reflect off of before it gets to your ears and it will sound better, also, dont make a box with the sub facing upwards, it will just ratter the shit out of your hatch, not a good idea. also, this may sound like a no brainer, but plan ahead as you put the box together, especially if its gonna be ported, cause once you glue and screw parts in they are not coming off, so make sure you can get to certain parts before you glue then together. i planned all my wood out first, then took my plans down to home depot and had the guy cut it up in his huge saw, very cheap and easy on my part. if its for you shop classes make sure to be EXACT when you make you cuts, if one wall is too short or too tall, you could try and fill in that gap with extra glue, but that can rattle out over time, best idea is to be very careful, and precise with the cuts, remember, measure twice, cut once.

ok, thats all i can think of now, as for terminal posts, wires and that black carpeting that makes the box like legit, i went to a local audio shop and bought all those, you will probs need a dremmil or roto-zip to cut the circles for those, better than a jigsaw for circles IMO. and for the wiring, you wanna see how many ohms and how many wires you will need to run inside the box, you can hook the wires up to the terminal posts inside the box after the fact, but its easier to do it all before and then just snake the wires inside the box and the screw the terminal posts into the side of the outside of the box AFTER you put on the carpeting, if you are gonna put on the carpeting. you do it after so you will can cover up the cut edges of the cut carpet, also when making the hole of the terminal posts, you should make it a bit too small first and then slowly open it up, so that it will fit snug, if its too big to start with, your fucked. haha

ok, i cant even remember your question, i just wanted to try and vent everything i learned when making my box. any other questions?

[Twizt1d]

I built a complete Deck which eliminates my trunk completly but add some tweeters or maybe 2 8 inches and it wouldd be sick...it hold 2 sony xpold 10's and they face up and rock out... will post pics tomorrow morning

[brendon]

Thanks for the help guys, I appreciate it.

[westonian18]

Originally Posted by axispiral

i doubt that you will be able to fit a 12" standing up in the trunk,

dont make a box with the sub facing upwards, it will just ratter the shit out of your hatch

If you want to do this I have kicker l5's and i built my box with 3/4 inch mdf and it fits, but barley.So theres some subs that will fit.

My subs face up and the bass sounds amazing against the rear winshield.As long as you have it so your box fits under the lip of the seats it works out awesome, well at least it did for me .

[braxthnc]

subwoofers are actually omnidirectional. the bass is going to be radiating in all directions from the sub.

[GSU3000gt]

Originally Posted by braxthnc

subwoofers are actually omnidirectional. the bass is going to be radiating in all directions from the sub.

True. But porting or firing the sub against the back glass of our cars does make a pretty noticible difference.

I have a Fosgate HX2 Power 15 incher. No way it'll fit in the trunk without removing the spare and cover. I just laid the back seat down and have the 3" port firing into the galss at the base of the rear glass. No need for those back seats anyway, they're tiny.

Back to the original poster. Just pay attention to the tech specs of your sub. There are numerous things to take into account. Mounting depth, thickness of box material, minimum rear clearance, cone excursion. etc.

P.S. - A 15" Power HX2 BEATS in a 3000GT. Had to reattach the rear-view mirror about 3 times. I had two of them in an S-10 and they didn't have anything on the ONE in my car.

[973000GTSL]

Originally Posted by GSU3000gt

True. But porting or firing the sub against the back glass of our cars does make a pretty noticible difference.

I have a Fosgate HX2 Power 15 incher. No way it'll fit in the trunk without removing the spare and cover. I just laid the back seat down and have the 3" port firing into the galss at the base of the rear glass. No need for those back seats anyway, they're tiny.

Back to the original poster. Just pay attention to the tech specs of your sub. There are numerous things to take into account. Mounting depth, thickness of box material, minimum rear clearance, cone excursion. etc.

P.S. - A 15" Power HX2 BEATS in a 3000GT. Had to reattach the rear-view mirror about 3 times. I had two of them in an S-10 and they didn't have anything on the ONE in my car.

You also have to make a bigger box for a ported sub. I have never liked the sound of ported boxes. They seem too "loose" and if not done right sound real shitty. Maybe its just me but if you want loud, go ported, if you want quality, go sealed. I use to goto sound comps when i worked for tweeter, i built a PT crusier for alpine and JL, did not see too many ported boxes except in SPL comps. Just my 2cents

[copperhead069]

I was able to get a 15" MMATS sub in the trunk without having my seats down. The box is flush with the back of the back seats and sits at a slight angle firing at the back glass. It has a "step" down so it fits under the deck lid and that is where i have the amp mounted. I didnt have to remove the spare or the lid, its actually kinda easy to remove the box, just 2 quick clips and removing it. Its heavy as hell but yea it can be removed in an emergency situation with one person, trust me not fun but possible. I can upload pics if anyone is interested in my design.