Subwoofer custom boxes + placement

onlytrueromeo · Post by **onlytrueromeo** » September 25th, 2007, 9:03 am

Currently I'm running a single 12" 300watt JL audio sub positioned towards the back of the car. It sounds OK (crappy deck/amp, stock front speakers) and I want to upgrade the audio in my car and try to free up some trunk space in the process. I've been looking into building custom fiberglass and MDF sealed boxes in the two corners of the trunk closest to the back of the car, with a slight angle upwards - probably with 10" subs. I know that the car acoustics make the bass sound best when the sub is positioned when I have it not, but I'm not going for competition level sound, I just want something that sounds good for daily driving, and the occasional outside party where I crank the sound so we can have music while we drink outside

So, 2 sealed corner boxes facing the center of trunk/front of the car w/ (insert name brand here) 10" drivers?

Thoughts?

Thanks!

~Romeo

Aston Wards · Post by **Aston Wards** » September 25th, 2007, 9:38 pm

Yeah, that sounds alright, subs are pretty bulletproof when it comes to postioning, the biggest thing to watch out for is unwanted vibrations

s1zzl3 · Post by **s1zzl3** » September 26th, 2007, 2:01 am

if your not going for competition sound then positioning shouldn't be a big deal
but i wouldn't recommend building a box yourself unless you no exactly how to
trust me its complicated id say leave that to the experts
im not doubting your ability im just saying itl be a pain in the a--
plus i mean y spend your money on building 2 boxes when u can use it to upgrade your system.. for example instead of buying 2 10" type-r's maybe buy a 12" alpine type-x?
having a box for the type-x saves a lot more space then having two boxes for your two 10"s

onlytrueromeo · Post by **onlytrueromeo** » September 26th, 2007, 7:14 am

I dont REALLY want to build the box myself, but I dont really want to spend the money to have it built professionally. I agree that I could get much better quality w/ just 1 sub, but the car is my daily driver and I want to free up more trunk space, and corner boxes just seemed like the best idea. What if I were to just use 1 single sub in a corner, that way I could keep my cost down and get a better driver...

How much can I screw things up w/ building the box? I know I need to provide good support inside the box, and I need to comply to the minimum volume and make sure the box is sealed and seated in the car well. After that, how much does the shape/geometry of the box affect the sound? I've been reading up as much as I can, but without real life experience, you are right it's going to be tough.

I want good bass sound but with more trunk room than I have now

s1zzl3 · Post by **s1zzl3** » September 26th, 2007, 2:05 pm

if your gonna build it your self itll be just as expensive as buying a smaller pro built box
a professional box may run you 150-300 for a 12"
depending on the volume u want plus brand name
if you go wit a smaller volume and have a really good sub that can run at that volume
then ur set
i have a type-x in a very roomy box..the type x can run at volumes between 1-2 cu. ft and its in a 1.75 cu. ft box
lets say u get a smaller box and shove it into a corner
then ull have sum pretty decent space left over

here look at my setup
remember thats a 1.75 cu. ft box

i have sum space on the sides and if i really wanted i could push it over and and have a bit more...go with a smaller box and itll save you sum more space plus sound extremely good

jus my opinion you could always try building the box yourself
but ill warn you its not as easy as it sounds

Aston Wards · Post by **Aston Wards** » September 26th, 2007, 10:20 pm

If space is a priority, you might want to go with a Bazooka or similar tube subwoofer, i've got a passive Bazooka in my 2+2 300ZX (space is a serious issue

)

matt753 · Post by **matt753** » September 27th, 2007, 8:24 pm

Just curious to see what everyone has done about unwanted vibrations/rattling? I have dual 12" kicker subs and a rockfordfosgate amp, with new speakers and deck and everything, which has a lot of power, so when i turn it up there are a lot of vibrations and rattling. It seems it is everything doing it (plastic panels on inside of trunk, spoiler, license plate, bumper, etc). I know you can buy trunk kits, but do they really work?

Vanished · Post by **Vanished** » September 27th, 2007, 9:04 pm

I highly suggest doing this

http://www.mx-3.com/phpbb2/viewtopic.php?t=54386

simple, you don't have to worry about what it looks like, and you get all the trunk room you've EVER WANTED. No loss of space, only loss of a spare tire. Yes i know i still need to finish the cover for everything (soon..very very soon..)

wagZE · Post by **wagZE** » November 9th, 2007, 9:49 am

dont have them facing each other they'll canccel each other out sound like shyt. A spare tire custom box isn't that difficult if you've made anything with fiberglass before. Use alot of mat. If you go to a stereo shop you;d be lookin at $800 at least. If I were you I'd stay sealed to keep the box small if you do a ported enclosure you'll have to make it bigger.
Check out this link:
http://www.the12volt.com/installbay/for ... 74519~PN~1

onlytrueromeo · Post by **onlytrueromeo** » November 9th, 2007, 10:03 am

Yeah Im buildin a custom box right up next to my rear seat to house my 12w3v3 - I will have cutouts in the back for the two amps and will keep the box as thin as I can

sinjin · Post by **sinjin** » November 27th, 2007, 10:43 pm

building a custom box into the sides of your car would be fairly easy, but the problem is having the knowledge to do it properly. the best solution would definitely be to build the back of your enclosures with fiberglass, then seal off the enclosure with a solid front of MDF or some other composite wood panel.

things to consider in reference to bass reproduction: bass is basically nondirectional, so positioning is not of extreme consequence. however, it is true that opposing subwoofers will tend to cancel each other out. another consideration is sound baffling. it's commonly known that a 20Hz soundwave requires approximately 55ft. of travel to complete. typically sound will bounce off of the surfaces inside your cabin until the required distance is acheived...but if there is enough obstruction then the frequency can become muted. this is why i generally prefer in smaller cars to have subs aimed towards the back glass, this should allow the bass to reflect from the rear to the windshield with little resistance and already fulfilling most of the required path for the soundwave. like you, i'm not into competition installs...but i prefer to take the guesswork out beforehand.

truthfully, the best option might be using the spare tire well. while it's a risk to go without a spare tire in case of emergency...this option affords you the most room as well as optimal positioning. i've seen many people achieve this by simply bracing a surface plate that's been precut to the well shape and chaulking it in place. some install a terminal plate for wire connections while others just drill a hole and chaulk around the wiring.

as for building your own box, a professional is not required. do the research to find how much airspace your speakers need. then measure and build. there are cheap boxes on ebay all the time...and if you must buy one a bit too small, you can fill it with polyfill from your local walmart. polyfill helps make the box perform as a larger space than it really is. for real.

onlytrueromeo · Post by **onlytrueromeo** » November 27th, 2007, 11:50 pm

Im going to be building a custom box over the Christmas break, I'll post pictures as I work on it. It will be my first box, and since I can never make things easy, I will be building a nice clean looking box (that will be very intricate). I got a 12"w3v3 thats in my old box right now (little too big of a box for the sub) until I can make my box. Im going with a sealed enclosure, and I have 2 JL amps mounted on the back of my rear seat. Digital Capacitor wired and mounted on the upper back of the seat, with just enough room for the hatch cover to close (when its finished being built). The box I want to build will have cutouts for the amps to sit behind the box, with a deeper spot in the middle so that I can keep the 6 3/4" mount requirement. The box will also taper back on top to make room for the capacitor, and will taper down on the sides to fulfill my small cubic ft requirement. I plan to build the box the full 39" across the trunk and keep it sticking out no more than 8.5" from the back seat. It sounds complicated and crazy (and it kinda is) but I will save a bunch of trunk room this way, and it will also look sharp.

Marquis · Post by **Marquis** » November 29th, 2007, 12:10 am

I know you said that your not looking for competition sound but the simplest way to make your bass louder is to get a hatchback box which angles the subs toward your rear windshield on which the sound reflects forward to the front of the car. I'm more of a db guy but I like to hear the bells and whistles too. Now I drive an Intrepid which has a trunk which brings up the question how do I know this hatchback stuff. My answer my best friend drives a '96 Eagle Talon TSI hatchback and his car is way louder than mine when using a cheaper setup than me. I asked our car audio dealers and they said that there are many reasons that subs can lose db, your subs will lose sound pressure levels in a car with a trunk, or in any truck, and that in a hatchback you need to have your subs toward the rear windshield to get the most out of them in either sound quality or SPL.

mazdags94 · Post by **mazdags94** » November 30th, 2007, 8:09 am

matt753 wrote:Just curious to see what everyone has done about unwanted vibrations/rattling? I have dual 12" kicker subs and a rockfordfosgate amp, with new speakers and deck and everything, which has a lot of power, so when i turn it up there are a lot of vibrations and rattling. It seems it is everything doing it (plastic panels on inside of trunk, spoiler, license plate, bumper, etc). I know you can buy trunk kits, but do they really work?

I had a similar setup in my old MX3, 2 12" Kicker Comp's w/ 500W Majestic Amp. I too had rattling but I went to my shop and bought an off brand dynamat (MUCH cheaper) and did my entire trunk and especially in my spare tire area. The spare tire area is thin and rattles outside quite a bit. I only did the bottom of the trunk and it made a HUGE difference especially for the rattling outside. The bass was cleaner as well. You could even go as far as doing the trunk walls to provide better rattling resistence. eBay has some cheap sound deadener sold by the yard. Take a look.

onlytrueromeo · Post by **onlytrueromeo** » September 17th, 2008, 9:10 am

I had a question about this the other day, and what I finally did. I decided to post some quick pictures in case anyone wanted to do something similar. I don't remember the box dimensions, etc but I can measure it if anyone needs. I used 3/4 MDF to build it, and finally covered it with charcoal felt this past weekend. My Car is a bit messy, but I'm switching everything from my RS to GS so it will eventually get cleaned up.

12 W3 V3

I know the sides don't look as good, but you can't really see them when it's installed in the car. I wrapped the felt completely from the front to back, and theres only 1 seem on the bottom, besides the separate pieces on the sides.

It's all hidden when you look at it from the front.

2 JL Amps

My unfinished doorpanel/speaker install. Switching to different car, so hopefully I will finish it there!

I ran all new speaker wire (pain in the a55!!) and am currently underpowering my sub with only a 250w amp. I love the sound, and I am underpowering it because I didn't have the $$'s for a 500w amp, and I don't need it to be that loud (although it does get quite loud w/ the momo's and JL)

MX-3.com

Subwoofer custom boxes + placement

Subwoofer custom boxes + placement

Re: Subwoofer custom boxes + placement