12volt dub ghettoblast

toiminto · Post by **toiminto** » Wed Jun 10, 2009 6:45 am

Hey,

thought I'd share with you the first pictures of my ghettoblaster I built

Designed for park/beach/city blasting, it has 12" peerless car subwoofer, 10" p.audio middle and 1" celestion compression driver. Driven with a blaupunkt 340 watt car amp and optima 55Ah leisure deep-cycle battery.

Tonight I'll do a stress test. I did a quick test and man it's loud and clear! Should do 112dB to 1 meter across 32hz-20khz

BOOM

spire · Post by **spire** » Wed Jun 10, 2009 7:22 am

what kind of crossover is that? well, i assume im seeing a crossover, could be wrong.

magma · Post by **magma** » Wed Jun 10, 2009 7:30 am

Nice... how much time do you get out of one of those batteries??

toiminto · Post by **toiminto** » Wed Jun 10, 2009 7:31 am

it's an active crossover by jvc:

http://support.jvc.com/consumer/product ... chive=true

bought used, it does it's job nicely. I use midbass channel for sub, highpass at 30hz, lowpass at 110-120hz. Then mid goes from 120 to 3k and from there up it's the celestion driver

toiminto · Post by **toiminto** » Wed Jun 10, 2009 7:32 am

Magma wrote:Nice... how much time do you get out of one of those batteries??

It remains to be seen, but I'm expecting at least few hours, probably 5 hours+. Today I will be doing some battery life tests with it

spire · Post by **spire** » Wed Jun 10, 2009 8:14 am

pretty decent crossover, parametric eq n all. impressed. thank you for not being dumb and just hooking everything up randomly, haha. i like seeing smarter peoples projects.

toiminto · Post by **toiminto** » Wed Jun 10, 2009 8:24 am

hehe yeah well I didn't want to just hook everything up randomly

It's a large (and heavy!) cab to move around but I got some chunky air fillable rubber tires for it and a handle, shoudln't be too hard. The sub has a large enclosure of 130 litres tuned to ~35hz, it should give a nice +4-+5 db boost around 40-50hz which is nice, then -3db point around 31hz. I can use the parametric eq to smooth the response out and thus save a little power (the sub hogs up most of the juice).

I only had a chance to test it out briefly but it sounded even nicer than I had expected

did · Post by **did** » Wed Jun 10, 2009 8:56 am

how the fuck did you hook a car sub up to a home speaker? or did i miss something and this is battery powered

toiminto · Post by **toiminto** » Wed Jun 10, 2009 8:57 am

DID wrote:how the fuck did you hook a car sub up to a home speaker? or did i miss something and this is battery powered

yeah, you missed something

It is battery powered all the way, intended for outdoor use for small parties / park blasting / sonic attacks.. Though you could still hook up a car sub to home use, why not?

did · Post by **did** » Wed Jun 10, 2009 9:08 am

i was looking it up and the power connection is a wierd voltage and is dead hard to hook up/you have to run it off a car battery. any suggestions?

spire · Post by **spire** » Wed Jun 10, 2009 9:28 am

DID wrote:i was looking it up and the power connection is a wierd voltage and is dead hard to hook up/you have to run it off a car battery. any suggestions?

well speakers can be run off of any kind of amp, its the amp that you gotta make sure is getting the right power.

like home speakers can work in cars/car speakers can work in the house, speakers are speakers. although car speakers sometimes tend to have lower impedances than home. avg home speakers are 8ohm, car, 4ohm.

i dont know if i answered anything or just ran around your question...

did · Post by **did** » Wed Jun 10, 2009 9:30 am

Spire wrote:
DID wrote:i was looking it up and the power connection is a wierd voltage and is dead hard to hook up/you have to run it off a car battery. any suggestions?
well speakers can be run off of any kind of amp, its the amp that you gotta make sure is getting the right power.

like home speakers can work in cars/car speakers can work in the house, speakers are speakers. although car speakers sometimes tend to have lower impedances than home. avg home speakers are 8ohm, car, 4ohm.

i dont know if i answered anything or just ran around your question...

yh sorry my bad it was the amp that i couldnt hook up. don't car subs need power to them tho? cus i hooked it up to my home amp before and it worked but not at all well

spire · Post by **spire** » Wed Jun 10, 2009 9:36 am

DID wrote:yh sorry my bad it was the amp that i couldnt hook up. don't car subs need power to them tho? cus i hooked it up to my home amp before and it worked but not at all well

yeah subs just require tons of power compared to mids and tweets. one way to convey the amount of power they need is that for every octave you go down (say from 200hz to 100hz), you need to push 4x as much air to acheive the same amount of db's. so from 100hz to 50hz, thats another 4x you need. like in my car ive got probly 20 watts going to each set of door speakers and ~350 watts to my sub and it all sounds pretty even.

did · Post by **did** » Wed Jun 10, 2009 9:38 am

so how would i achieve this off a home amp?

toiminto · Post by **toiminto** » Wed Jun 10, 2009 9:39 am

the amp must be able to handle low ohm loads (usually 4 ohm in car woofers) and give enough watts for the element. Also you probably need one with a high- and a lowpass filter in order to filter out the unwanted frequencies.

spire · Post by **spire** » Wed Jun 10, 2009 9:40 am

either have a seperate receiver/amp for the sub or build a crazy efficient enclosure.

did · Post by **did** » Wed Jun 10, 2009 9:41 am

fuck, complicated. would it be easier to buy a home sub? and if so whats a decent one? i dont need to have iration steppas in my room but want something beefy but crisp and pretty fucking loud

toiminto · Post by **toiminto** » Wed Jun 10, 2009 9:42 am

get yourself a decent subwoofer element, a sub amp and some wood, should do the trick. You can calculate the enclosure size using thiele small parameters and for example this great piece of software to simulate it:
http://www.linearteam.dk/default.aspx?pageid=winisdpro'

if you want to buy a subwoofer, there's lots of brands on the market. For example BK electronics, SVS, chorus etc.

spire · Post by **spire** » Wed Jun 10, 2009 10:04 am

budgets kind of a big deal, usually the amp is the most expensive part in DIY applications. theres some really solid less expensive speaker brands out there, Dayton Audio for example.

when you throw words like "beefy" "crisp" and "loud" in there the price jumps way up.

http://store.audioholics.com/product/19 ... woofer-kit

thats a pretty decent sub kit for the price. id be very surprised if theres any sub at your local electronics store that performs like this for the same ammount of money.

did · Post by **did** » Wed Jun 10, 2009 10:15 am

looks nice and just in the budget. anywhere i can get this in uk for same kind of price?

12volt dub ghettoblast

12volt dub ghettoblast

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