Car Speakers & Home Audio

[Darkness 77]

I was wondering if any of you guys know if i can hook up some Polk 6x9's to the B speaker outputs on my home amp. The only worry i have is that they are 4 ohm and my HIFI is 6 ohm. Is there an easy fix or am i wasting my time? Thought they would be sweet as outdoor speakers on my patio.

[dephilile]

You probably could put a resistor in series with your speaker. It would need to be at least a 2 ohm resistor and be able to handle the wattage you amp puts out. However, I wouldn’t do this. It’s a bit sus.

[Tasmaniak]

What delphilile said is quite true.

With that said though, so long as you are entirely aware that you are dropping the resistance to the amp, you are increasing it's output to quite possibily more then what it can handle. Then you could quite safely run them, but be CAUTIOUS as you are asking for more then what it's capable.

[Darkness 77]

Cheers fellas i dont think ill risk my amp

[Tasmaniak]

Wise move

[vy_pete05]

dont ever mix home audio and car audio, that have different resistance and impedence ratings...(as stated) and will do damage to either you speakers AND/OR your amp...no risk

[shaggerz]

You can, of course, combine home audio and car audio if you use a car amp to drive the car speakers. You could use a line level input into a car amp and run the 6x9s through that. I myself had a 5.1 channel home theatre system running using a JL Audio e1200 amp and a 12W0 subwoofer. Getting a high current 12V supply was easy. All you need is an old computer power supply!

[TigerVX]

Is it alright to do this with speakers that are the same Ohms as the amp of a wattage larger than the max output of the amp?

[Tasmaniak]

Chris, yes...

Shaggerz....wtf? A computers power supply is no more then 5amps tops! You need a good solid 20A AT LEAST to drive a subwoofer amp sufficently without fear of clipping.

[shaggerz]

5 amps? I think not! *reads from side of power supply*

DC Output
----------
+3.3V - 15A
+5V - 25A
+12V - 20A
and i'll stop there since thats the important one.

Before I got my VS I had a JL e1200 running from it. I played a test tone and measured with an oscilliscope and an ammeter. Found that even though it says 20A it drew a solid 27 amps before any clipping of the waveform was visible.

Anyways my ears were about to start bleeding at that point anyway :P

[barbs]

shaggerz tell me how you hooked the PC power supply to your amp as i happen to have spare sh*t around and wanna give it a try

[shaggerz]

Easy If it's an ATX power supply (It should be because AT power supplies are almost gone completely from the world) then you need to wire a switch into it to turn the power supply on and off. On the ATX connector (the big one that normally goes onto the motherboard) you connect the GREEN wire with any of the BLACK wires. You connect the amp's battery connector to a YELLOW wire on one of the molex connectors that are normally used to power hard drives and optical drives, and the amp's ground to a BLACK wire on the same connector. You'll have to use a short wire bridge to connect the battery input terminal on the amp to the 'remote turn on' wire or the amp won't power up.

A Few Points To Note:

* Check the CURRENT rating of the power supply's +12V rail. The higher the better. Don't bother with anything under about 15 amps as it'll simply not be enough power to get any reasonable volume without distortion. Obviously the higher the wattage of the power supply the more power will be available for the amp.

* DON'T turn the power supply on without the amp connected to it as it will probably not work and may damage the power supply. The reason for this is that switchmode power supplies (such as PC power supplies) require a load to work. Many have a built-in dummy load so that they don't blow themselves up but PC power supplies DON'T because you normally can't turn it on without it being connected to a computer.

* You may notice that the wires from the power supply to the amp are quite thin. This is indeed BAD. It matters a little less over the short distance from power supply to amp but it is best to connect more than one yellow wire to the amp battery terminal and more than one black wire. Normally a computer contains many devices so the current load is distributed across many wires, but in this case there is only one high current device (the amp) so you should connect as many wires as possible to decrease the overall resistance and prevent loss of power and possible fires due to the wires melting. Some people may tell you that you CAN'T do this, but I assure you all the supply wires of the same colour all connect back to the same point inside the power supply, so there is no danger of shorting or feeding the supply back into itself.

* You should NOT permanently connect the green and black wires and use the mains switch to turn the power supply on and off. Most power supplies don't like this at all due to the immediate current drain on switch on and will usually NOT START.

* Even doing it this way you might notice the power supply sometimes (or if you are unlucky) always won't start when you flick the switch. This usually means that there's just not enough load to start it and you can usually just add another device such as a fan to get it started. (90% of the time this won't be a problem though.

* If you do something DUMB and accidently short out the power supply, don't panic, it's probably not dead. Most PC power supplies will switch themselves off if shorted and will not start again until they have been unplugged and the capacitors inside have had a chance to discharge. Your best bet is to pull the mains plug out of the wall and leave it for a few minutes. Once you plug it in again it should go back to normal.

If you need any more help, feel free to ask