making box for megacab

[deadbroke]

got the idea of putting 2 12's in the truck still in the deciding stage here on what i want to do on the box how to finish the bracing and maybe porting. here is what i have so far







for the subs i was thinking re audio ssx 12, hk12x2, and idmax 12.

i havent done many ported boxes before so ideas would help. i was thinking of making the port right above the Speaker holes in picture one or port from the top in the last picture not sure.
any suggestions on the inner bracing ribs if i should seal off each sub chamber and port them individually or open them to the other sections?

[666WMD]

You could just drop some ports in on the top as you already suggested. Would probably be the easiest way of doing it. 3" each chamber for a bit of SQ, 4" for SPL and low end.
Cutting the bracing out enough to make it a single chamber would be a pain in the ass and you might have issues trying to make a port big enough and long enough for a single chamber, unless you have a good 6" to one side of the box that you could port firing at the side of the cab.

[666WMD]

What are the dimensions of that box or at least what's the internal volume? The HK's need A LOT of space, 3cuft is massive for 12's. I personally don't like RE, but they'd probably be your the best of your 3 choices.

For around $200 a sub, I'd suggest looking at SSA Gcon's, Sundown SA's, or TC Epic 12's. I think Xmax would win in your situation if you don't have a lot of Power to throw at them.

[cxa0897]

Those sections look very small for a ported 12. Another option is to pop 10s in there to port, could be done fairly easily and they need a lot less space

[deadbroke]

well the box is 21 tall 5 1/2 to 12 deep and 57 long. i really could have made it bigger but i didnt want to mess with fiberglass i still have my project truck to work on. im not too sure what subs i am getting i was looking in the 1000 rms per sub range these subs spoke to me im trying to keep the speakers under 1400 i still have an alternator and amp to buy. im surprised the idmax arent that popular i always hear good things.

the bracing was just cut to fit i haven't put them in yet so i can take them out i just wanted some type of bracing for the box.

[cxa0897]

no where near enough room for a 12 ported in each chamber, that works out to under 1.5 per chamber. you can definitely run a sealed 12 in each, or run a 10 ported in there, by doubling up the front baffle with 10" cutouts.

the idmax are very good sq subs, not really the best subs in terms of output though.

the market is absolutely flooded with subs that'll take 1000rms, so you have tons of options there.

sa12s or oa 12s are rated for 600? but are known to take 1k all day every day and sound quite good for under 200 a pop. profundus is actually selling a bunch of em in the classifieds which you can scoop up for a nice deal. ssa has the gcon, which is likely a very good subwoofer as well.

i would personally stay away from re, as their ownership changed and is no longer what they once were. on the sq side of this, tc epic 12s, fi qs or the idmax are all very good subs.

all depends on where you wanna take it i suppose. with some more info on your goals we can narrow down the options a bit

[deadbroke]

im more spl but i havent shopped for speakers on a budget in a while

[666WMD]

Just re-read the original post. This is only for two 12's?

[deadbroke]

Yeah sorry I meant 4 12s

[cxa0897]

i still vote for mounting a new baffle with ported 10s. i honestly feel it would be louder than any 12s you could stick in there..

[rugersr9]

Originally Posted by deadbroke

well the box is 21 tall 5 1/2 to 12 deep and 57 long. i really could have made it bigger but i didnt want to mess with fiberglass i still have my project truck to work on. im not too sure what subs i am getting i was looking in the 1000 rms per sub range these subs spoke to me im trying to keep the speakers under 1400 i still have an alternator and amp to buy. im surprised the idmax arent that popular i always hear good things.

the bracing was just cut to fit i haven't put them in yet so i can take them out i just wanted some type of bracing for the box.

Just from my experience I would get a second battery before a alternator and just have 2 runs of 1/0 front front to back with a big 3 you're voltage should be fine depending on how you run you're subs.

[deadbroke]

i changed my mind i had been wanting to get dc audio subs but last time i had spoke to them they wanted a lot more money so i'll be getting level 4s put them in this box until i go bigger.

i can make the box 62 wide 24 tall 7 inches deep at the top and 13 at the bottom i just didnt plan on the subs more or less plus i didnt plan on cutting anything or removing the rear trim wall. thanks for the help guys much appreciated.

[666WMD]

Originally Posted by rugersr9

Just from my experience I would get a second battery before a alternator and just have 2 runs of 1/0 front front to back with a big 3 you're voltage should be fine depending on how you run you're subs.

Just from your experience you should have learned that an alternator should be the first thing you buy when going over 3kwrms. You wouldn't have had half the problems with voltage drop and your amp getting hot if you'd fed it the right power to begin with.

Originally Posted by deadbroke

i changed my mind i had been wanting to get dc audio subs but last time i had spoke to them they wanted a lot more money so i'll be getting level 4s put them in this box until i go bigger.

i can make the box 62 wide 24 tall 7 inches deep at the top and 13 at the bottom i just didnt plan on the subs more or less plus i didnt plan on cutting anything or removing the rear trim wall. thanks for the help guys much appreciated.

With those dimensions you'll end up with 6.1cuft net volume before any displacements and using a double baffle, which I would highly recommend to support heavy subs sitting on an angle.
Have you taken into account the distance the subs will mount out from the face of the box and the excursion possibly hitting the back of your seats? You'd need an additional 3" right there.

Due to the space restrictions, I would suggest you only use 3 12" subs and aero ports to save space. And here's why. 6.11cuft - sub disp of 0.3 = 5.81. Minus 2 6" ports 18" long = 5.17cuft net. 5.17 divided by 3 subs = 1.72cuft of airspace per sub and that's not even including any kind of bracing in the box.
Were you to use 4 subs, the displacements go up and the volume goes down. 4 subs are now in 1.26cuft net airspace each. You would have to be feeding them more than their rated rms to get them to work right in that small a volume.

Now 4 12's will have 1900cm/2 surface area, but your really pushing your luck getting them in that space. 3 12's will have 1440cm/2, how ever 2 15's will get you 1620. And they will fit in that airspace better. DC lvl4's won't, they need 3.25 each. Sundown Zv3's will though since they only need 3cuft even. Realm of Excursion - Sunfire - There is no Sundown Audio as an option Lol yup

Now to support 3500-4000wrms, you're gonna need one big alternator and a few batteries. Talk to Sintorman on here about a 350amp unit, will run you around $400. You'll want to aim for around 250-300ah in batteries, so 60-80 up front and 220 in back. That should set you back about $600.

Good luck.

[deadbroke]

before posting i took a look to see the volume of the box using one of those calculators the volume came out to almost 6.7 cubic feet and with speaker displacement the net volume came out to about 6.5 maybe the calculator isnt that reliable but if its right i figured the bracing would probably balance that out to about 6 so help me out here on what i was doing wrong.

the subs look like they would clear the seats pretty good just because of the angle and how far down they are getting mounted.

i was looking online and i found dc alternators selling a 300 amp for 500 bucks and someone on here is selling one for 400 with more amps i have to talk to this gentleman.

[666WMD]

Originally Posted by deadbroke

before posting i took a look to see the volume of the box using one of those calculators the volume came out to almost 6.7 cubic feet and with speaker displacement the net volume came out to about 6.5 maybe the calculator isnt that reliable but if its right i figured the bracing would probably balance that out to about 6 so help me out here on what i was doing wrong.

the subs look like they would clear the seats pretty good just because of the angle and how far down they are getting mounted.

i was looking online and i found dc alternators selling a 300 amp for 500 bucks and someone on here is selling one for 400 with more amps i have to talk to this gentleman.

Your calculator is right, it is 6.7 net before anything. Put a double baffle on that and it drops to 6.11. DC lists their Lvl 4 12" displacement at 0.18, which is a lot more than I figured as most 12's are around 0.1. So 4 of those drops your net to 5.39. That's 1.34 per sub sealed, which you would be fine with as DC recommends 1cuft. If you want to have 4 DC subs then you will have to settle for them being sealed. Ported is not really an option for the space you have and those subs.

If you are going to run 6000wrms I'd suggest looking at 2 15's ported over 4 12's sealed. Sundown NS 15's would do the trick.

[rugersr9]

Originally Posted by 666WMD

Just from your experience you should have learned that an alternator should be the first thing you buy when going over 3kwrms. You wouldn't have had half the problems with voltage drop and your amp getting hot if you'd fed it the right power to begin with.



With those dimensions you'll end up with 6.1cuft net volume before any displacements and using a double baffle, which I would highly recommend to support heavy subs sitting on an angle.
Have you taken into account the distance the subs will mount out from the face of the box and the excursion possibly hitting the back of your seats? You'd need an additional 3" right there.

Due to the space restrictions, I would suggest you only use 3 12" subs and aero ports to save space. And here's why. 6.11cuft - sub disp of 0.3 = 5.81. Minus 2 6" ports 18" long = 5.17cuft net. 5.17 divided by 3 subs = 1.72cuft of airspace per sub and that's not even including any kind of bracing in the box.
Were you to use 4 subs, the displacements go up and the volume goes down. 4 subs are now in 1.26cuft net airspace each. You would have to be feeding them more than their rated rms to get them to work right in that small a volume.

Now 4 12's will have 1900cm/2 surface area, but your really pushing your luck getting them in that space. 3 12's will have 1440cm/2, how ever 2 15's will get you 1620. And they will fit in that airspace better. DC lvl4's won't, they need 3.25 each. Sundown Zv3's will though since they only need 3cuft even. Realm of Excursion - Sunfire - There is no Sundown Audio as an option Lol yup

Now to support 3500-4000wrms, you're gonna need one big alternator and a few batteries. Talk to Sintorman on here about a 350amp unit, will run you around $400. You'll want to aim for around 250-300ah in batteries, so 60-80 up front and 220 in back. That should set you back about $600.

Good luck.

I 'll have to disagree I had one battery and a 200 amp alt. on a 3500k amp and it did nothing . My alt produced the power but there was no where to store it soon as I got a second battery I seen a huge difference! What good is a power supply if there is no where to put it. Trust me I bought my alternator first thinking the same thing and nope all that $$ spent and it didn't do anything till I put more batteries to it.

[cxa0897]

Didn't you also install a second run of 1/0 at The time of the battery? Pretty sure that makes a huge difference, much more than the batt did

[666WMD]

Originally Posted by rugersr9

I 'll have to disagree I had one battery and a 200 amp alt. on a 3500k amp and it did nothing . My alt produced the power but there was no where to store it soon as I got a second battery I seen a huge difference! What good is a power supply if there is no where to put it. Trust me I bought my alternator first thinking the same thing and nope all that $$ spent and it didn't do anything till I put more batteries to it.

Let's see here, a 200amp alternator and an amp capable of drawing 400+amps @ 0.5ohm..... and you wonder why that didn't work???

Simple fact is, if he wants to push 4 1400wrms subs, HE WILL NEED A BIGGER ALTERNATOR. Unless he wants to cart around 600ah worth of batteries and have his amps continually dropping to less than 12 volts, he will need the biggest alternator he can get.

[rugersr9]

Originally Posted by cxa0897

Didn't you also install a second run of 1/0 at The time of the battery? Pretty sure that makes a huge difference, much more than the batt did

Yeah 2 runs of 1/0.

[rugersr9]

Originally Posted by 666WMD

Let's see here, a 200amp alternator and an amp capable of drawing 400+amps @ 0.5ohm..... and you wonder why that didn't work???

Simple fact is, if he wants to push 4 1400wrms subs, HE WILL NEED A BIGGER ALTERNATOR. Unless he wants to cart around 600ah worth of batteries and have his amps continually dropping to less than 12 volts, he will need the biggest alternator he can get.

Yeah he will need a bigger alternator true but at idle or a red light whats feeding the amp one battery?

[666WMD]

Originally Posted by rugersr9

Yeah he will need a bigger alternator true but at idle or a red light whats feeding the amp one battery?

Where the fcuk are you getting this one battery from?? I said right from the outset, a 350amp alt and 300ah of batteries.

[rugersr9]

Originally Posted by 666WMD

Where the fcuk are you getting this one battery from?? I said right from the outset, a 350amp alt and 300ah of batteries.

Why you getting mad!! Do I upset you? chill the hell out bro I'm not arguing I was just saying! This is a car audio site to talk and so grow up!

[666WMD]

Originally Posted by rugersr9

Why you getting mad!! Do I upset you? chill the hell out bro I'm not arguing I was just saying! This is a car audio site to talk and so grow up!

Yeah good on ya.

[rugersr9]

Originally Posted by 666WMD

Yeah good on ya.

Ok I'm not arguing you're point all I was saying is I couldn't afford a bigger alt. and batteries at once SO I should of got a second battery before my alt. because that alt and one extra battery did nothing so I ran dual 1/0 and installed a second battery then got better results inall said if you had 2 even 3 batteries before you're alt. all you could do is a big 3 and double power wire to support them extra batteries and you're voltage should be good till then. But if you can get it all at once then great! I'm not trying to pick a fight this is a forum I'm just saying my experience not that you're wrong cause you're not so hummmmmmm I didn't have to swear in that did I its cool just talk!