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Car Audio for Home Theater

Last response: in Home Theatre Legacy
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February 9, 2008 4:25:40 PM

Hey.

As a bit of project to pass the time, I've been looking into ways to convert a full car audio system for home theater use. I've run into one or two roadbumps however...

The only real issue I've been having is building a rectifier for the 120 volt AC to 12 volt DC power. I'd need to have about a 2000 watt power handling. This is the main part I want to be able to build myself. I've looked a little into switching mode power supplies (SMPS)...the extremely high frequencies on the load side means that filtering is easier, shrinking inductor size to managable sizes...but the actual build itself is proving hard to find. And until then, I can't figure out the diode (bridge), transistor (current amplification), capacitor, inductor, and resistor specs.

Any ideas that anyone might have would be very welcome...I'm not 100% set on the SMPS idea...and if anyone knows a site that could give me an idea how to build this, you'd be saving me a lot of headache.

More about : car audio home theater

February 22, 2008 8:07:52 PM

I once tried to use a car amp/subwoofer in my hometheater but getting ample 12v in the house was more expensive than a 120v amp.
March 14, 2008 3:54:49 PM

First and foremost, if you don’t have an electronics or electronics Engineering background I would not recommend for you to build this thing, too risky. This is when the professionals say don not do this at home. :) 

You understand that having that much current on 12V DC requires mucho respect on the current flow. 1 false connection will damage your Entire project and may end up hurting yourself. That’s 166.66 AMPS that need to be rectified.

A capacitor that will handle that much power will be around $150 or more. A transformer will be as big as a car battery maybe a truck battery. And you still need the diodes and the voltage regulator that can handle that very high current. I'm not even sure if I could recommend using PCB. Can you Image the heat sink you’ll need to use on the diodes and the voltage regulator?

Your best bet is to look at the converter designs, and a UPS system designs. Find a charger that can do high loads of batteries and use the charge batteries for your AMPS.

But any direction you chose will cost no less than $600.

If I were you, I'll get a higher Grade Home Amplifier that can handle 4 Ohms and if you already own the speakers it's just easy as connecting to the amp. Will be around $2500 and up depend of the wattage. Don’t be misled about low wattage ratings since these Amps are lower distortion than the one you find at Best Buy or Circuit City for that matter.

Unless the speaker box requires more wattage then look at power Amps that will do 2 amps, Like Bryston amps.

Edited: I meant 2 OHMS
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January 13, 2009 9:45:50 PM

Hi mtriples,

I've just completed my home theater system made from car stereo bits. I had to really hunt around for a power supply that would put out enough amps and watts. It was going to cost me about $1000 (NZD) for a transformer that was big enough. There was no way that I was going to spend that. As a replacement I bought a 12v car battery and a battery charger, total cost $120. If the battery works out to be not big enough I will just buy another one and add it into the circuit.

I have use all fusion gear, two 10 inch subs, two 6.5 inch 3way speakers. All connected to a 4 channel x 100watt amp.

Hope it helps
January 14, 2009 5:59:33 AM

mightymat2 said:
Hi mtriples,

I've just completed my home theater system made from car stereo bits. I had to really hunt around for a power supply that would put out enough amps and watts. It was going to cost me about $1000 (NZD) for a transformer that was big enough. There was no way that I was going to spend that. As a replacement I bought a 12v car battery and a battery charger, total cost $120. If the battery works out to be not big enough I will just buy another one and add it into the circuit.

I have use all fusion gear, two 10 inch subs, two 6.5 inch 3way speakers. All connected to a 4 channel x 100watt amp.

Hope it helps


The thread was of spring 2008.

Anyway, you would be lucky if you can manage to get your car battery to last at least 2 years because it's not design for repeatedly and rapidly charged and discharged. You will need an especial battery like one use for HEV (Hybrid Electric Vehicle).

Just my curiosity, how much power your charger produces?


January 15, 2009 5:52:00 PM

rexter said:


Anyway, you would be lucky if you can manage to get your car battery to last at least 2 years because it's not design for repeatedly and rapidly charged and discharged. You will need an especial battery like one use for HEV (Hybrid Electric Vehicle).

Just my curiosity, how much power your charger produces?


The battery isn't rapidly discharged and charged. I have been using the stereo for about 8hrs now and the battery still has charge, and I have a 12v DC 2700mA battery charger on a timer that will trickle charge it over night.

What I thought was that you only use a stereo for a couple of hours a day and if the battery is topped up at night while its not being used that there shouldn't be any problems.
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