one or two boxes?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=38928
Printed Date: May 19, 2024 at 9:11 AM
Topic: one or two boxes?
Posted By: hightek
Subject: one or two boxes?
Date Posted: September 10, 2004 at 2:37 PM
last night i was talking about my system with some friends and one of them said that i should put both subs into a sealed box instead of having seperate boxes for them. he said that sometims the subs will fire at different times and this can cause one sub to blow. i don't really believe him but i just wanted to get all of your thought, ideas, opinions, facts on the subject.
i'm making my own box(s) and i was looking at some on the web and even the dual sealed ones had a divider in them.
Replies:
Posted By: dxav
Date Posted: September 10, 2004 at 3:19 PM
If you have 2 subs running mono from one amp, then single chamber will work fine. In any other situation, separate chambers should be used.
Good luck!
DXAV
Posted By: jeffchilcott
Date Posted: September 10, 2004 at 3:35 PM
I almost always seperate my subs unless they are a lower series sub like a JL wo no matter sealed or vented I normaly devide chambers
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: hightek
Date Posted: September 10, 2004 at 6:04 PM
so if i were going to bridge the amp then i would want a single chamber box?
what if i bought two of the same amp would that be better than running one big one bridged?
Posted By: kfr01
Date Posted: September 10, 2004 at 6:28 PM
hightek wrote:
so if i were going to bridge the amp then i would want a single chamber box?
what if i bought two of the same amp would that be better than running one big one bridged?
I don't think that is what they said. I think they said: If you don't bridge the amp then definitely use separate chambers.
If you do bridge the amp then a single chamber is O.K., but two chambers is optimal. I totally agree with what they said, if for no reason other than two chambers will make the box more stiff and well braced. ------------- New Project: 2003 Pathfinder
Posted By: 12-volt_guy
Date Posted: September 10, 2004 at 7:44 PM
No two speakers are exactly alike, even if they are the same model. Manufacturing processes just aren't perfect. If you have two drivers in the same cavity, they are like to have slightly different characteristics and may affect each other's movement, resulting in some distortion. This is the same reason they don't recommend a stereo amp configuration for two woofers in the same cavity; amplifier channels are different too and you'd have a similar problem, not to mention that stereo signals are different anyway. At least in a mono configuration, both woofers would get a more equal signal. And the center divider tip probably is the best because enclosure rigidity is of utmost importance.
Posted By: hightek
Date Posted: September 10, 2004 at 7:45 PM
i know that two subs would definately sound louder than one but i'm worried about space and stuff after i shoved my model box in the trunk, it's huge. would it still sound alright putting one back there? i like to have the bump when i need but i also just like the little heart thumping you get when you turn it up. if i match a right amp to one sub is this still possible?
what i built smaller boxes and used polyfill?
Posted By: hightek
Date Posted: September 10, 2004 at 7:48 PM
so from what i'm gathering from 12-volt_guy is that it is better to have the subs wired in a mono configuration? i was thinking about having two seperate boxes? does this matter?
Posted By: 12-volt_guy
Date Posted: September 10, 2004 at 8:13 PM
hightek wrote:
so from what i'm gathering from 12-volt_guy is that it is better to have the subs wired in a mono configuration? i was thinking about having two seperate boxes? does this matter?
Two separate boxes are fine. One "chamber", multiple woofers is what you should avoid, especially if not running mono. Perhaps we should say "chamber" instead of "boxes", because a box is typically considered to be a unit, regardless of how many chambers it contains.
Posted By: 12-volt_guy
Date Posted: September 10, 2004 at 8:20 PM
Additional note: When placing the woofer position in the box, do not center it in the box. Move it close to a wall. Centering drivers creates standing waves. Also, if mounting two woofers in a single "box", it is best to mount them close together, like near the center divider. This allows acoustic coupling and improves bass output.
Posted By: hightek
Date Posted: September 10, 2004 at 8:37 PM
alright, well now i'm thinking about buying one 10" sub. maybe an adire brahma or something that really hits. but what kind of amp would i match with that?
do you all think i should just go with what i already have or get the 10"? i'm trying to save some space in the trunk, it's a coupe so i'm already limited on space.
i also talked to a guy at a custom install place in my city and he said that if i got a red top battery then i would not have to worry about lights dimming or anything like that. is this true?
Posted By: 12-volt_guy
Date Posted: September 10, 2004 at 8:52 PM
An amp of 150-200 watts RMS total should be plenty for nearly any situation other than competition. Ever check out home subwoofers? 10" powered subs seldom have more than that and many times only about 75 and they generally fill up a large room quite nicely. An amp of this size shouldn't make your lights dim, even without an extra battery. I can't speak for your musical tastes, but some people are head bangers. They want too much bass in their systems and don't know much about balanced sound. I have had customers with 4 fifteens that would blow an amp or woofer and then try to say "I don't play it loud". If you didn't, you wouldn't have 4 fifteens. -------------
Posted By: 12-volt_guy
Date Posted: September 10, 2004 at 8:55 PM
Hmm.. That profile thing said you could use forum codes in your sig. Apparently not. -------------
Posted By: hightek
Date Posted: September 10, 2004 at 8:58 PM
so you're saying that even though the rms wattage for a 10" adire brahma II is like 400 an amp that pushes about 200 would be good?
as far as music tastes go i listen to everything from rap to rock to techno to R&B to oldies
so sometimes i like to turn it up and really listen to the bass hit, but usually i just like to have a little extra bass than is provided by 6x9s
Posted By: mobile E
Date Posted: September 11, 2004 at 6:42 PM
what? the rms wattage for a brahma is like 400? Actually i think its 1600 , check the website man... thanks ------------- everything stolen :(
Workin on a new system :)
Peace in the middle east
Posted By: Steven Kephart
Date Posted: September 12, 2004 at 4:19 AM
The thermal power handling of a Brahma is 1600 watts. But that does not mean that you need that much power. You can easily reach the physical limits of the Brahma off of 700 watts in the right enclosure. Also, you would be surprised at how loud a Brahma will get off of only 500 watts, even in a small sealed enclosure. Based on what you are trying to do, I would suggest around that much power for you. hightek wrote:
i also talked to a guy at a custom install place in my city and he said that if i got a red top battery then i would not have to worry about lights dimming or anything like that. is this true?
That isn't true. The only thing a battery does is provide power to start your vehicle. It does absolutely nothing except get charged back up when you are driving. This is because the battery can only charge up to 12.6 volts as it has 6 2.1 volt cells. The alternator runs at 14.4 volts and supplies the power while you drive. Now if you draw too much current, then the voltage will drop till the current draw isn't too high. This voltage drop is the cause of your head lights dimming. Now if the voltage drops below 12.6 volts, then yes the battery will start supplying power. But your voltage shouldn't drop down that low. If it does, then you will need a larger alternator. Steven Kephart Adire Audio -------------
Posted By: 94legend
Date Posted: September 12, 2004 at 5:43 AM
12-volt_guy wrote:
Additional note: When placing the woofer position in the box, do not center it in the box. Move it close to a wall. Centering drivers creates standing waves. Also, if mounting two woofers in a single "box", it is best to mount them close together, like near the center divider. This allows acoustic coupling and improves bass output.
Wow this is really useful THANKS this whole time i was wondering wut the hell is the sub doing all the way to left / right of that box. ( the box was a ported/vented 15" sub)
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