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car subwoofers in a room

Printed From: the12volt.com
Forum Name: Miscellaneous - Off Topic
Forum Discription: Topics that just don't fit anywhere else.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=76473
Printed Date: April 24, 2024 at 6:42 AM


Topic: car subwoofers in a room

Posted By: anotherloserkid
Subject: car subwoofers in a room
Date Posted: April 19, 2006 at 2:11 PM

anyone know how or what i would need to put 2 12" infinity car subwoofers in my bedroom so i could hook it up to the tv????



Replies:

Posted By: godblessdremil
Date Posted: April 19, 2006 at 3:34 PM
buy a cheap surround sound system. It would be cheaper.




Posted By: anotherloserkid
Date Posted: April 19, 2006 at 5:34 PM
i dont really care about the price, its just something iv  wanted to do, and i think it would be tight




Posted By: godblessdremil
Date Posted: April 19, 2006 at 5:47 PM
Dam my posted 3 times, well first you would need a power supply big enough to run the amp that can get expensive just a 40 amp will cost you about 150-200 dollars min. now i do not know if the amp can run the signal from a tv but i believe there is a converter that you can buy.




Posted By: anotherloserkid
Date Posted: April 19, 2006 at 6:19 PM
what if i hook it up to a reciever?




Posted By: stevdart
Date Posted: April 19, 2006 at 11:54 PM
You can use your Infinity subwoofers in your home system.  You'll need to build a box suitable for those woofers in a room environment (think larger than in a car), and power them using a receiver.  Home theater stuff.  You will also need a center channel and front main speakers.  Rear surrounds would be good, too.  Subs by themselves won't do a thing for you.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: DYohn
Date Posted: April 20, 2006 at 12:49 AM

I don't know of any receivers that will power a subwoofer.  There is no difference using car audio subs inside than using home theatre subs, you just need the proper enclosure.  Like Stevdart said, you'll need to construct a home theatre-style enclosure and purchase a subwoofer amplifier designed for use in the house.  Hmm, two Infinity Perfect 12's in about 9 cuft ported at 18Hz with a 500 watt plate amp should be about right.  I cannot recommend you try to use any car audio amplifiers inside.



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Posted By: anotherloserkid
Date Posted: April 20, 2006 at 4:47 PM

thanks alot.

Why does a home theatre box need to be so big???

and how would i figure out the port size? cause if you use a calculator online for a car box wouldnt it be off?





Posted By: stevdart
Date Posted: April 20, 2006 at 9:40 PM

If you were to work up a subwoofer built for car audio use in a box-building program (see my WinISD sticky in the Car Audio forum and go through the steps for a good learning experience), you'll likely see recommended cubic feet that are larger than a lot of the manufacturer's recommendations for box size.  The small confines of the car audio environment introduces a proportionally greater "cabin gain" to the overall sound than a room in a home does.  I would basically just tend more to the small side for the car and to the large side for the home.

Manufacturers of subs (the good ones, anyway) build some characteristics into the woofer to allow it to perform to its best in one environment or the other, and that has to do with room size.  You know that a room in your house is larger than the room in a car, and that is what they model when they develop these subs.  The characteristic differences are shown in the parameters provided by the sub manufacturer, so you can model either a home sub or a car audio sub in the program and it will come out right.

You definitely want to model this sub if you are intending to port it.  Box tuning has to do with the airspace in the box, so whether it's for home or car the tuning will be appropriate...as long as it's good for the sub in question.

hint:  post the model of your subs and then follow DYohn's advice on box size.  He has built home theaters for the stars.



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: anotherloserkid
Date Posted: April 21, 2006 at 6:53 AM

there 2 12 inch Infinity reference





Posted By: DYohn
Date Posted: April 22, 2006 at 12:59 PM
Put two Infinity Reference 12" woofers into a single chamber that is 5 cuft net and port it at 24Hz (dual ports 4" diameter X 10.5" long.)  Use a 250 watt subwoofer plate amp like THIS and you will get >118db @ 45Hz and in-room response should be >100db down to 20Hz.  Should sound pretty good in 5 cuft sealed as well.  In fact, sealed might actually sound better now that I look at the graphs, and it'd be a lot easier to build!

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Posted By: 92bgze
Date Posted: April 22, 2006 at 9:20 PM

This is my 1st post, but I think I may have some feedback on using car subs in the house..

I have 2 12in audiobahns in a sealed enclosure that I have a dedicated reciever used just to power them (old sherwood rv-1340r w/ eq). I use a seperate reciever for the fronts, center, etc. What I really want is to build a passive crossover for them, but I dont know how and is actually how I stumbled upon this site. Back to topic..

The subs face the wall in a corner and are well hidden.....And let me say it is insanely loud and deep. Movies are awsome to watch, and I suppose an actual home theater setup would suffice, but I like the bass. The mid can get  a tad harsh up too loud but the eq helps a little.

a good idea, go for it .





Posted By: saturnsubohio
Date Posted: April 24, 2006 at 7:51 PM
i did it with a car amp and my W7.

here is how i did it.

Computer PSU (cheap dont care if it blows)
Amp
Speakers

* I TAKE NO RESPONSIBILITY IF YOU BREAK SOMETHING*

cut off a Molex (the 4 pin connector) and use the Yellow Wire as 12v and use the black as ground.. then take a jumper wire from RMT to 12v

then short out on the 20(24) pin cable from the PSU the Green and black wire.. or pin 4 and 6 respecitively.

i had my w7 shaking stuff off peoples walls 5 rooms down which is solid concrete walls.





Posted By: anotherloserkid
Date Posted: April 25, 2006 at 10:14 PM

i dont follow you

whats a computer PSU?

Im not to good with electronics.....





Posted By: saturnsubohio
Date Posted: April 25, 2006 at 11:43 PM
Computer Power Supply Unit.

the thing that you plug into the wall from the back of you Computer.

its rated in Watts, which is the sum of Amps*Volts on the "Rails"

I cant really get into the details.. but a cheap one is like 350 W, a good one is like 550W



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2006 WRX STI
Electrical Engineer
Ohio University Alumni




Posted By: anotherloserkid
Date Posted: April 26, 2006 at 8:08 AM
that sounds tight. I might give it a try if i get bored




Posted By: saturnsubohio
Date Posted: April 26, 2006 at 10:02 AM
again....


* I TAKE NO RESPONSIBILITY IF YOU BREAK SOMETHING*

now i'll explain why not to do that.

Power supply units supply DC Voltage @ the following levels 12v,5v and 3.3v the general gauge in the computer world of how good a PSU is, is its Amperage on the 12v Rail. The highest commercially available PSU can deliver about 70amps @ 12V... however the car amp i hooked up drew more and i certainly wasnt using the top of the line..

bottom line, your amps will pull ALOT more current than the PSU can deliver, and it delivers 12v MAX sometimes it may drop to 10v or lower depending on load. you can blow your amp and the PSU or both.

but a W7 @ 900W is really loud.. and a great way to prove a point that you dont want to listen to Jungle Fever for 8 days straight.

thats the premise for the story.

Sorry for the long post

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2006 WRX STI
Electrical Engineer
Ohio University Alumni




Posted By: DYohn
Date Posted: April 26, 2006 at 10:40 AM

saturnsubohio wrote:

i did it with a car amp and my W7.

here is how i did it.

Computer PSU (cheap dont care if it blows)

This is NOT a good idea for the average person unless they know somethng about electricity and how to work with it safely.



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Posted By: saturnsubohio
Date Posted: April 26, 2006 at 10:45 AM
Very Very True.. DYohn.

Guys my suggestion would be do not try it. It was dumb of me to do, knowing full well the laws of electricity, here's the simplified reason why not to do it

you have an amp which pulls 100Amps the PSU can supply @ most 40amps.

something is not right in Dodge with #'s like that.

but it does work, and worked for about 3 months with no major faults

PS: Im an EE Undergrad and a Dedicated Computer Overclocker.

-------------
2006 WRX STI
Electrical Engineer
Ohio University Alumni




Posted By: eternal1
Date Posted: April 30, 2006 at 10:40 AM
i never thought of doing it that way always figured it would be enough power for it. though the thought did cross my mind:) what i ended up doing was just using some old speaker cabinents (kenwood) and put two cerwin vegas in the wholes and some cheap (radio shack) mids and tweets using the existing crossover. it was powered with a 200watt pioneer receiver. sounded really great for a long time. however i did run into the problem that most home receivers (back then at least) wont drop to a 4ohm load. since mine were dual voice coils it was no problem to put them at 8 and shake the room. if your speakers are 8ohms or can be made 8ohms then i would go that route and make those your front left and rights.




Posted By: eternal1
Date Posted: April 30, 2006 at 10:42 AM
i never thought of doing it that way always figured it would be enough power for it.

sorry it should read not enough power for it





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