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Discussion Starter #1
So i was interested in building vented box, casue my friend has one, and his system sounds alot better then mine, even though im runnin more power.

biggest questions i have are...to build the perfect vented box for my two subs, what information would i need? also. as far as layout and design of the box goes, is there some sort of program i can get online that will help me with the dimensions?
 

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Heres what i know. Each sub needs a certian amount of air behind it, or it's movement will be restricted and it will sound like crap. Find the "optimal box", work out the cubic inches and translate that to your custom box.

Mouse
 

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kathemius said:
So i was interested in building vented box, casue my friend has one, and his system sounds alot better then mine, even though im runnin more power.

biggest questions i have are...to build the perfect vented box for my two subs, what information would i need? also. as far as layout and design of the box goes, is there some sort of program i can get online that will help me with the dimensions?
You're gonna have to do a ton of research.

1) Do you have the same subs as your friend? In the same car? With the same power?
If not, then it's not a fair comparison. Sealed, Ported, Bandpass, etc. all have different characteristics.

2) The balance of Power, Type of Box, Box Volume, and Car environment, are all factors that play off each other. Frequency cutoff points, Subsonic, LowPass, Slopes, Box positioning, Blend with Midbass, Midbass being used up front, etc. etc.

3) Contact your sub manufacturer to see what they suggest based on your intended goal for the given subs.

Sources to research:

http://www.diysubwoofers.org

http://www.bcae1.com

http://mobile.jlaudio.com/support_pages.php?page_id=127

http://forum.elitecaraudio.com/index.php
 

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Discussion Starter #6
I'm running 2xRF P310D4 and that ap2000 profile amp (specs can be seen at crutchfield).

As for my firend, he's got a couple pioneer subs and an interfire amp. neither of them are real powerful from my understanding.

So yeah. I think honestly, it's mostly my box. Guess that's what i get for listening to the guys at bestbuy :)

So what information do i actually need? I mean. I'm good at building stuff, but i've never built a sub box.
 

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1) We need to make sure you have the subs to amp wired correctly to get the most power.
You have dual 4 ohm subs. Wire each of them in Series individually for an 8 ohm load each.
Then wire the 2 of them in Parallel to the amp for a final 4 ohm load.
The amp should obviously be set and/or wired for bridged mode.
This will give a total of up to 960w RMS at 4 ohms bridged.
That amp may not actually put that out, but close enough, since each sub is rated 400w RMS each.

2) We need to know what your LP frequency setting is on the amp.

3) What size is the sealed box? Internal cubic feet? One big open box, or dual individual enclosures?

You can't really compare the two setups fairly, but we'll help you dial in your setup to sound it's best. Does your friend have 10" or 12" subs? How much power total RMS? What sized ported box and at what frequency? LP cutoff? Subsonic?

For future reference, please answer all questions, and post the information and specs so we don't have to search for it. We are here to help you, so you do the homework. I did it this time, but the more info we have, the better. [;)]
 

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Discussion Starter #11
Sorry. I usually do more posting with that type of information, but like, yeah, i was in a rush, and now im at work. So yeah.

1) Ok, i dunno hwo to actually wire the subs, correctly, the display at fosgates website is a bit confusing for me.

2) LP: variable low-pass filters (50-250 Hz, 12 dB/octave) (is this the right info?)

3) and as far as my sealed box size, i have no clue, like i said earlier, i listend to the guy at bestbuy, cause he said it would make the best combo.

My firends got two pioneer subs, and an interfire amp, i think it's only a 400w amp or so.

Anything else im missing.
 

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1) you'll have to unscrew a sub to look inside. do it slow so you don't mess up the screw holes, especially when putting it back together; don't do too tight.

You need to note exactly how the whole thing is wired. Should be like this:


2) Make sure the switch is set to LP (not HP), then slightly turn it past 50 up to 80Hz. So, LowPass from 80Hz and down at a 12dB slope (second order).

3) measure the outside dimensions of the box, all dimensions.
when you take a woofer out, measure the thickness of the wood, ie: 1/2" or 3/4"
is it one open box, or is there a divider, other internal walls, etc?

We need to make sure your current system is setup properly before you make any major changes.

Also, what head unit do you have, and what is the sub output level on the head unit. And where is the gain set on the amp as well? (gain should have a range listed, guess the voltage position)
 

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Discussion Starter #13
Got an answer back from RF and they say...about 1.75 CF per speaker. So that's the best answer i got so far. :)
 

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Discussion Starter #14
So knowing how much cubic feet i need per sub. is there any good programs out there that'll help me get the right dimensions for the vented box?
 
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