Do me a favor and keep your speaker box free so you can spin it around when you get it all hooked up.

After that I doubt you will install it in that position.

Also if you spin the subs around and mount them to a strong piece of wood you can free air them into the rear hatch glass for a nice low bass, but you will reduce power handling substancially.

heres a little diagram of what I mean.

 

unfortunatly, "spinning it around" won't be possible due to the way I'm making the box, it's not perfectly square, it is offset so that the subs sit better inside the bin spaces. I also don't quite understand your diagram, is the brown line supposed to be the top of the sub, with the red lines being the air waves, bouncing off of the black small line which is the hatch glass?

 

the brown line would be your wood.
the red lines are the sub itself.

 

what do you mean by 'you will reduce power handling substancially'?

 

Any free air use will reduce your power handling by about 3/4 of what its rated at. Basically, a speaker needs RESISTANCE to handle more power. If you try to push in the cone of a free air speaker, it will go easily. If you try to push in the cone of a speaker in a small sealed box (NO air leaks), it is substantially harder to push in. Its this resistance that gives the speaker its max power handling. The most ideal setup is to achieve your speakers X-Max (the maximum movement of the cone in ONE direction from at rest) at the maximum power handling. For example, I would want to use a box that provides enough resistance so that for a speaker with 500 watts max power handling won't exceed its X-Max at that power, while not going under. I don't know if that makes sence, but thats how it is.

 

You better check the specs on your subs. Most subs can't even by played in a free air environment. Some can though. Think of this situation. You need resistance to get somewhere right? When you swim in water, resistance is propelling you. There is mass, there is something physically there to move you. When you fly in a helicopter, there is much less mass getting yourself to move, it just has to be applied on a much greater level. Thus the open subs needing more POWER to move them, their essentially swimming in air. Get it?

 

Thats true about the sub being built for free air. You will damage any sub thats not built for it. But I don't know if what GavinJuice is saying is correct. There is little resistance on a speaker in open air. Therefore it requires less power to move. When in a small sealed box, you are essentially compressing the air in the box when the speaker moves in. Basic physics explains that it takes more POWER to compress air. THIS is the resistance a speaker needs. Just moving air back and fourth is not enough for a speaker.

Think of the speaker in free air as a sound wave. A sound wave is a compression type wave. It requires very little energy for a sound wave to move through air. Thats why it moves so fast. In essence, the speaker in free air is just doing this same back and fourth motion like a sound wave. There is almost no resistance to this. Its like swinging your hand through the air. There is little resistance.

 

These subwoofer threads make me feel old...

You young bucks must have ear drums of leather - subs just give me a headache.

Rock and Roll never needed a subwoofer!

 

yup makes me feel old too. But I don't listen to rock and roll and if I did put a sub in it, it would be to hear the bass over my poud exhaust not to have everyone hear it. I would also custom hide it underneath the carpet where the spare tire was that doesn't fit my car.

 

Well the only reason i would want to get a sub would be to add to the music. Not cover up everything with loud muddy bass, god I hate rap. I'd aim for a system where i can hear things you wouldn't hear with a stock system, and loud clarity over the exhaust Oh yea, then i could blast Guns N Roses RXTbone so everyone could listen to some good music. YEAA

 

I turn my system up and get crunk in my car...

 

Your best sound quality is gunna come from a sealed box, with most subs some will sound best in a band pass box I loved my sealed boxes. Also the best way to get the best sound from your sub is to go by the box spec listed with the sub. (get a better sub sorry not a fan of sony or jl) but in general 1 cube per 12" sub is about aveage and gives a good sound I most cases.
I have had my 12" subs hit 150+dbs in this size box and without clipping and with minimal distortion, this is way beyond normal listening volume, at this volume ear protection is maditory if you plan on beeing in the car even that may not help. Sub size is really dependant on the music u listen to and will change the sound drumaticly. General rule for your average off the shelf sub, The smaller the diameter of the sub the sharper the hit, but the larger the sub the deaper the sound.
8-10" good for rock and cuntry or any thing with hard pounding drum or sharp bass guitar
12" good all round
15"+ more muffled with a deaper blurrier bass sound
rapp hip hop and music with a lot of bass not as sharp unless you go comp. grade equipment and spend $700+ on a sub
ok end of my lecture hope its help full
PS make sure you run heavy enough cable as it really sucks to burn of a cable(been there done that)

 

Thanks, good to see some audophiles that know their stuff on the forum.

 

I'm an audiophile in learning from my dad. He has built some of the best sounding sub I have heard. He is mostly into home and pro audio, not cars. So I know that any speaker if put in the right box will be tight and bassy. He is currently working on a project using 2 Lab12's made by eminence to handle about 2000 watts and be able to outperform 8 18's. This box will not work in a car though. A car isn't big enough for it, not even a large van is big enough to have enough room to let the wave expand.

 

I'm not prejustice against sony...i even own a sony amp, but sony makes some of the worst car audio equipment in the biz. I would try to sell those and get some real subs and amp.

 

I got them off of e-bay for $40 a pop, as well as xplod 6x9's (in speaker boxes) for $54 ~boxes are about $30, so it's like the speakers were $24 (all of this includes shipping too) So that's why I went with the craptacular sony stuff. If I had money, I'd get good equipment... but that's why I'm going to college now.

college now = poor now = job later
job later = lots of money
lots of money = able to afford good stuff
good stuff = happy me.

it's all very simple

 

Couple things, Sony stuff is a joke it might sound good for a little while but its not made to last at all... Other brands will last you for years with little trouble right now im running 2 Clarion 12's in a sealed box ill post a picture ASAP hmmm how do you post a picture on here anyways?

 

again, i know that sony stuff isn't very good. however, it is cheap, and will hopefully last me until i can get some funds up to get some good stuff. I sold the sony amp and am looking into alpine or maybe jbl. not quite rockford fosgate, but at least it's better than sony. i post pix by uploading to a tripod web space, then linking to it.

 

Not all Sony stuff is cheap. My MP70 deck set me back a pretty penny

 

Ported boxes are the best compromise between the three basics of enclosure design: frequency extension, SPL, and SQ.

Low frequencies are where it's at.

 

::my:: sony stuff was all cheap. And honestly I don't have anything against most of sony's stuff. as far as their car audio stuff goes, it's not the best, but i DO think that it looks pretty cool. anywho, it's what i have, and i'm poor as dirt, so it doesn't matter much if it's the best or the worst stuff out there, cuz it's what i have.

 

The Sony headunits are killer....I've got two that have been in several cars and outlasted the cars....both are still perfect almost, what? 7 - 10 years later?

 

i've never had (or to my knowledge seen) a sony headunit, i've had an aiwa, and am now going to be using a kenwood head unit

 

hey guys, i'm back at school and have begun to work on the box again - here it is a little more than half done...

caulk like woah.









it's comin together :-)

(pardon the crappy job, that particle board is really really hard to work with... but the caulk should have made it airtight[IMG]

 

haha! whats with the bad *** rim on the spare?

Sony is ok, at least your not getting lightning audio My friend with a beretta got 2 12" 300W subs and a 400W amp. He built a huge box that replaced his back seat for them. All they do is buzz, no bumping coming from that crap. Its pretty depressing, really.