.75 or 1 inch mdf
02-26-2010, 03:49 PM
#1
Registered User
Thread Starter
iTrader: (37)
Join Date: Sep 2008
Location: SoCal
Posts: 1,133
Likes: 0
Received 0 Likes
on
0 Posts
.75 or 1 inch mdf
how thick should i make my box?
im going to build a box for 2 13w7, its going to be 4.9 - 5.0 cubic feet, and i was wondering if .75 inch thick mdf would hold. I want to use 1 inch thick but as we all know space is limited in the z. i dont care about the weight issues and i dont care if you say that 2 13w7s is an OVERKILL
.... guess what 
......................its my car
once again thank you for your input
im going to build a box for 2 13w7, its going to be 4.9 - 5.0 cubic feet, and i was wondering if .75 inch thick mdf would hold. I want to use 1 inch thick but as we all know space is limited in the z. i dont care about the weight issues and i dont care if you say that 2 13w7s is an OVERKILL
.... guess what ......................its my car once again thank you for your input
02-26-2010, 07:17 PM
#5
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
you'll need bracing or it will flex like crazy.
that being said, 3/4" MDF is perfectly fine with bracing. I would assume it's going to be ported due to the huge volume therefore there will be even less stress on the box which is in favor of the thinner MDF.
on an even final note, 3/4" MDF and then fiberglassing the inside of the box will be more rigid than 1" mdf without fiberglass.
that being said, 3/4" MDF is perfectly fine with bracing. I would assume it's going to be ported due to the huge volume therefore there will be even less stress on the box which is in favor of the thinner MDF.
on an even final note, 3/4" MDF and then fiberglassing the inside of the box will be more rigid than 1" mdf without fiberglass.
Trending Topics
02-27-2010, 10:42 AM
#10
Registered User
Thread Starter
iTrader: (37)
Join Date: Sep 2008
Location: SoCal
Posts: 1,133
Likes: 0
Received 0 Likes
on
0 Posts
im still trying to figure out the design but im almost there
, ill post pics when its all confirmed. yeah i need all the luck, this thing is so TIGHT, but hey for the price i got both 13w7 its worth the try
you'll need bracing or it will flex like crazy.
that being said, 3/4" MDF is perfectly fine with bracing. I would assume it's going to be ported due to the huge volume therefore there will be even less stress on the box which is in favor of the thinner MDF.
on an even final note, 3/4" MDF and then fiberglassing the inside of the box will be more rigid than 1" mdf without fiberglass.
that being said, 3/4" MDF is perfectly fine with bracing. I would assume it's going to be ported due to the huge volume therefore there will be even less stress on the box which is in favor of the thinner MDF.
on an even final note, 3/4" MDF and then fiberglassing the inside of the box will be more rigid than 1" mdf without fiberglass.
my head hurts, but it will be ALL WORTH IT in the end 
i knew someone would say it, lol its cool, to each his own 
oh and just to let you guys know im going to make the box sealed, if only i can get away from bracing and make the box and make it rigid enough, but i think im going to use 3/4" MDF and the fiberglass since i will get the most space out of it, and brace the inside with 3/4 MDF or something smaller like 1/2 MDF or even 1/4 MDF ..... ill keep you guys updated i just read a email from travis and now im second thinking it, but who knows maybe just maybe, it will fit, oh well back to the drawing board
02-27-2010, 03:35 PM
#11
Registered User
iTrader: (6)
Join Date: Oct 2008
Location: ny
Posts: 1,582
Likes: 0
Received 0 Likes
on
0 Posts
I dont think your really thinking this through. The electrical you would need to properly push those there 1000 watts (rms)2000 (peak) per sub .there under rated so they can actually take more. Even if you wire them at 1 ohm you would need minimum 2k watt amp thats stable at 1 ohm(ballpark figures). Not to mention your front stage you would need two sets of components to support your sub stage. Our cars put out 110 amps your gonna need a HO alt not to mention a second battery and those subs are 76 lbs each plus the weight of all the wiring and the box. When all is said and done your adding nearly 500 lbs of stereo equipment to a 2 seater sports car. Not to mention even if you do get all this done your not even gonna be able to sit in the car with it half way turned up. If your using it to compete thats one thing but get yourself a beater not a Z. Please think this out cause it really doesnt make any sense. Plus it will be EXTREMELY costly (no offense)
Last edited by duro78; 02-27-2010 at 03:42 PM.
02-27-2010, 08:49 PM
#13
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
things i'm confused on with this:
why such a large enclosure?
secondly to that question: why are you using a sealed box since you are so large of an enclosure?
Large sealed boxes aren't optimum by any means. You only need a huge enclosure if you are going to port the box due to the possible tuning frequency which would make the port extremely long.
I do'nt have my tuning software here on my laptop. I use a simple tuning program called "boxplot" if you want to look it up. Based on that subs T/s parameters 2.5 cf per sub is large. I decided to check out what JL recommends and it is on the large side of the size and is also tuned to 36hz which is actually pretty low. The low tuning would be a reason for their recommendation of such a large enclosure. Their recommendation for a sealed enclosure would put it below 4 cf and i think is on the large side for a sealed enclosure.
I'm thinking realistically 1.5 cf per sub sealed would work just fine. I would take a stab in the dark without computing the t/s parameters and say that the average person wouldn't notice the difference in performance even using 1 cf per sub sealed enclosure.
Like stated above, i wouldn't put anything less than 1000w per sub (so a JL1000.1 amp per sub). For that you're going to need to get the alternator rewound for higher output or find a large output alt that fits into the car. 1/0 gauge main power wire would be required to supply that amount of amps without severe voltage drop from source to amp. so yes, a very expensive setup.
why such a large enclosure?
secondly to that question: why are you using a sealed box since you are so large of an enclosure?
Large sealed boxes aren't optimum by any means. You only need a huge enclosure if you are going to port the box due to the possible tuning frequency which would make the port extremely long.
I do'nt have my tuning software here on my laptop. I use a simple tuning program called "boxplot" if you want to look it up. Based on that subs T/s parameters 2.5 cf per sub is large. I decided to check out what JL recommends and it is on the large side of the size and is also tuned to 36hz which is actually pretty low. The low tuning would be a reason for their recommendation of such a large enclosure. Their recommendation for a sealed enclosure would put it below 4 cf and i think is on the large side for a sealed enclosure.
I'm thinking realistically 1.5 cf per sub sealed would work just fine. I would take a stab in the dark without computing the t/s parameters and say that the average person wouldn't notice the difference in performance even using 1 cf per sub sealed enclosure.
Like stated above, i wouldn't put anything less than 1000w per sub (so a JL1000.1 amp per sub). For that you're going to need to get the alternator rewound for higher output or find a large output alt that fits into the car. 1/0 gauge main power wire would be required to supply that amount of amps without severe voltage drop from source to amp. so yes, a very expensive setup.
02-28-2010, 07:02 PM
#15
agree with binder on box size. a box that large would be comparable to free air/infinite baffle and will sound like crap with those subs. box specs and construction is just as important as proper power and quality equipment. it will be a waist of time/money/space/weight.
unless you are going to port it, which i would recommend. i have bassbox pro software if you would like me to calculate a tuning freq. and port size.
unless you are going to port it, which i would recommend. i have bassbox pro software if you would like me to calculate a tuning freq. and port size.
02-28-2010, 08:34 PM
#16
Looking at the requirements for this sub on the JL Site, I don't know how you'd even be able to get a ported box built for the Z for two 13w7's (4.75). You'd be more likely to reach a goal of 3.5 Cubic feet with two 12w7's. I have 2 8w7's and those hit amazingly well. Good luck hitting your goal, but it just seems like you're going to be disappointed if you don't reach it and it's not a very probable goal.
03-02-2010, 06:36 PM
#19
Registered User
Thread Starter
iTrader: (37)
Join Date: Sep 2008
Location: SoCal
Posts: 1,133
Likes: 0
Received 0 Likes
on
0 Posts
sorry but ive been really busy
ok since i didnt really explain to you guys why i want the box so big, its bc i want the i want the qtc to be .707 sints that will allow the sub to hit the lowest possible, and thats the # cubic feet i got in order to get QTC of .707, thanks to Paul350z i relize that this is all science. and well #'s dont lie.
Paul and travis have been alot of help and i cant thank them enough
but since its not %100 fact that i can get that box built in a z well honestly i dont SH*T money were i can just experiment....lol.
i know what im getting into, im already looking into a h.o. alt, ive been looking into excessive amperage 350 amp alt. but ive also been told that its too much and ill regret it, but if you have any input then im all open ears,
honestly ive been through SO MANY SETUPS that im F*n in doubt ill ever be satisfied, SO THIS TIME IM just thinking GO ALL OUT and if it dont work then screw it i hit my limit in this car, and just TT it. and keep it for performance.
Paul and travis have been alot of help and i cant thank them enough
but since its not %100 fact that i can get that box built in a z well honestly i dont SH*T money were i can just experiment....lol.
i know what im getting into, im already looking into a h.o. alt, ive been looking into excessive amperage 350 amp alt. but ive also been told that its too much and ill regret it, but if you have any input then im all open ears,
honestly ive been through SO MANY SETUPS that im F*n in doubt ill ever be satisfied, SO THIS TIME IM just thinking GO ALL OUT and if it dont work then screw it i hit my limit in this car, and just TT it. and keep it for performance.
03-03-2010, 08:48 AM
#20
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
no such thing as "too much" for an alternator output. Never believe a word from that person ever again because they are clueless.
350 amp alt sould do the trick for that level. 200amp would probably be the lowest i would use and i think that would be cutting it close.
so you want a qtc of .707 but this setup you have doesn't sound at all like it will be an Iasca type car. You would never need that much "bass" in a car setup for SQ. There wold have to be a balance.
Great for your goals, i'm not saying don't do it but i'm just confused. You are putting an SPL setup into a car and wanting to attempt (attempt is the word because it won't balance out) to set it up as an SQ (iasca) style system. That's like building a drag car that gets good gas mileage. They contradict themselves.
Also, if you use multiple thick layers of fiberglass and line the whole hatch area you could easily get that volume out of a 350z. Basically you would have to form the box to the hatch for max use of space. It can be done.
350 amp alt sould do the trick for that level. 200amp would probably be the lowest i would use and i think that would be cutting it close.
so you want a qtc of .707 but this setup you have doesn't sound at all like it will be an Iasca type car. You would never need that much "bass" in a car setup for SQ. There wold have to be a balance.
Great for your goals, i'm not saying don't do it but i'm just confused. You are putting an SPL setup into a car and wanting to attempt (attempt is the word because it won't balance out) to set it up as an SQ (iasca) style system. That's like building a drag car that gets good gas mileage. They contradict themselves.
Also, if you use multiple thick layers of fiberglass and line the whole hatch area you could easily get that volume out of a 350z. Basically you would have to form the box to the hatch for max use of space. It can be done.