I bought and hooked up a pre own system from a friend.
I have a 2 12" enclosed box.
Now my question is would it be better and louder to make hole in the box?
If so maybe a suggestion on how big of a hole I should make it?

Simply making a hole does not make a port. Whats subs and what are the box dimensions and what amp are you useing. Whats the impedance of the subs?

there are many complex calculations that go into box building. the first thing is what kind of subs your have specifically cause they all require more open space, u normally need less for a enclosed box then a ported box, also if your making the box square rectangle cylindrical all make a difference as well as if your maxing a round port or a slotted port.then going into how much depth you need for said port type. if you want a good box and can follow blue prints i would be happy to work something out with you and send you some blueprints. my friend is the owner of underground audio out of sarasota Fl,and i have worked in his shop from time to time as well as helping him out with some of his personal builds. it will take time and effort to get the most out of what you have, but it can be done i put out more dbs in my nissan maxima with a properly built box then ppl that had put over 10k in to their car and i did it for well under a grand. I only used 2 12s that were basically middle of the pack in terms of quality others had 2 15s 4 12s and 1 s10 had 2 12s and 4 10s and i was louder then all of them simply by maxing proper use of the air space that my car provided as well as porting the box properly

There are many variables. I would never just "cut a hole"!!

Box dimensions are L32"xW top12-1/2" bottom15-1/4xH14-1/8"
That's the measurement to the outside of the box idk what the material used is but it's probably 3/4" partical board.
The back on the box has a slant the top is abit more narrow than the bottom.
2 12" JL audio subs 4ohm 150RMS, 250RMS peak.
Infinity 312RMS 2ch AMP.
Bridged running on 2 ohm stable.
I have a 2007 Chevy Impala

If this helps.

And for the question of blueprints I'm a carpenter and qualified to create my own blueprints so yes I can follow them really well lol

And when I mean cut a hole, I was thinking maybe drill a 2" diametre hole.
But of course before doing something potentially stupid is why I'm asking.
Because it felt like I got more power out of my old set up which was one 10" sub in a ported box. That's why I thought about maybe doing this.

This post was edited by gaby444 on Apr 18 2015 10:10pm

the port requires length. not just a opening.

cutting a hole on your box no matter what size will make it sound crappy. you wont get a thump anymore youll end up with a very soft sounding system.

pre fabs are usually tuned to 45 hz.
the length of the port height of the port and width of the port all added up is what gets your box tuning.
you cant simply cut a whole in the box to make it ported for better sound. the only way youll get better sound of of your box by cuttin a hole in it is if you port it with some pvc then youll add port length but youll have to take in your internal box dimensions and figure out what your tuning freq will be with certin diameter pvc tubing and width of it.

if you want a ported box i would just go get one honestly. because i doubt your box is big enough in the first place to even have it ported and sound right.

Thanks for the reply, that's what I wanted to do with the pvc pipe.
Just don't know how to go about it I guess, I didn't even know about those variables honestly. I mean if the best thing is to leave it as is then I guess il just leave it.

just get a new box.

your sealed box is small. a ported one will be larger

or join some forums for car audio and get yourself some help designing a box. there is planty of people who will creat blueprints for you for a price if you feel like building it yourself

I don't even know where to begin to start to be able to help you. I seen you post some advice for other people and i thought this guy might have some sense. Then this post totally cancels that out. Read. Research. Before making comments or post.. What model subs are your jl's. Single or dual voice coil...

The things that I do know is one thing but there are things I don't know and I'm not going to pretend like i do.
Idk the model but they are dual voice coil.
And I mean idk the science that comes into play when it comes to the volume needed in a box / dimensions / shape or what not.