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I realize whatvI posted may have come off a bit dickish and don't want it to. I really agree with what you have said and try to put that to practice as closely as possible in my home and mobile audio systems. Have to to hear after all the heavy listening done in my younger years.
 

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Ok dumb question. Now that I have my JL Audio amp installed, what happens to the power that is IN the head unit? Where does it go once you hook up an aftermarket amp? You know the 22Wx4 that's built into the HU. Does it supplement the after market power amp? Get turned off/bypassed?
 

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Ok dumb question. Now that I have my JL Audio amp installed, what happens to the power that is IN the head unit? Where does it go once you hook up an aftermarket amp? You know the 22Wx4 that's built into the HU. Does it supplement the after market power amp? Get turned off/bypassed?
If you've added an amp and no longer using the amp inside the source then it's just less the power supply in the source has to work. That power is turned into a cleaner signal for your jl amp.
 

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Ah thanks. So it becomes dead weight then.
I wouldn't call it dead weight- it's more like tossing a few hundred pounds of weight in your car- car being the power supply in the headunit- the weight being the internal amp- then removing the weight. The car or power supply is less taxed and has an easier time which should in theory equat to better cleaner output to the rca's
 

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Ok dumb question. Now that I have my JL Audio amp installed, what happens to the power that is IN the head unit? Where does it go once you hook up an aftermarket amp? You know the 22Wx4 that's built into the HU. Does it supplement the after market power amp? Get turned off/bypassed?
What the others have said is essentially true, but I'll take another stab at explaining it, and the answer depends slightly on whether or not you have RCA outputs on your HU.

Within your HU, you have the 'source' section, which is the radio/CD player/MP3 decoders, etc., that produce a Line Level signal. You could think of all of these as separate components in a stereo system, each with RCA outputs. Selecting any one of them is akin to using a selector switch with a bunch of inputs and a single set of RCA outputs (and a volume control on that output).
The next stage in your HU is the amplifier stage - where that switched/volume controlled signal gets a voltage and current boost in order to drive the speakers. Remember that's all an amplifier really is - a voltage and current booster.

If you have and are using RCA outputs to the new amplifier, you're just replacing the internal amplifier with bigger, better amplification. But as for what you asked, the internal amplifier will continue to produce that higher voltage output, but it has NO LOAD since the speakers are disconnected. A good analogy to this is a portable generator. If it has no load, it still produces pretty much the same voltage, but it is delivering no current (therefore no Power - Power equals voltage times current). And just as the generator will still suck back 'some' gas to keep running, your internal amplifier will still use a miniscule amount of electrical power to run, but it's simply working with no load.

If you are running speaker level to the inputs of your new amps, the same generator analogy holds true. The input impedance of the new amps will be much higher than a speaker. This means that the new amps 'draw' much less current from the HU amplifier. Thus as others have said, your HU now has it easy - the amplifiers are still working, and delivering much the same voltage, but much less current, and will likely sound a bit better.
 

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After the long, in-depth debate on this subject which took place here ( http://www.diymobileaudio.com/forum/general-car-audio-discussion/172544-help-me-understand-power.html) over the past few days, I feel like this sticky really needs to be edited. Despite most of it being true, the following section is patently WRONG, and needs to stop being repeated. Need clarification? See the thread I posted.

"The lesson in all this is that you can never have too much power, and that big amplifiers rarely damage speakers. Little amplifiers driven into clipping burn out speakers. In the scheme of high fidelity, that last barrier to realism is having enough power and being able to approximate real-life loudness levels. The lesson in all this is that you can never have too much power, and that big amplifiers rarely damage speakers. Little amplifiers driven into clipping burn out speakers."

Perhaps a better statement is that "Your sound system can never be too powerful. Despite not intending to listen to music cranked to 11, you really need more power than you might think to actually imitate the dynamics of a live performance."

I say "system" to imply both powerful amplifiers ALONG WITH speakers that can actually handle that power.

Because you can never have too powerful of a sound system, but you can certainly have too powerful of an amplifier.
 

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After the long, in-depth debate on this subject which took place here ( http://www.diymobileaudio.com/forum/general-car-audio-discussion/172544-help-me-understand-power.html) over the past few days, I feel like this sticky really needs to be edited. Despite most of it being true, the following section is patently WRONG, and needs to stop being repeated. Need clarification? See the thread I posted.

"The lesson in all this is that you can never have too much power, and that big amplifiers rarely damage speakers. Little amplifiers driven into clipping burn out speakers. In the scheme of high fidelity, that last barrier to realism is having enough power and being able to approximate real-life loudness levels. The lesson in all this is that you can never have too much power, and that big amplifiers rarely damage speakers. Little amplifiers driven into clipping burn out speakers."

Perhaps a better statement is that "Your sound system can never be too powerful. Despite not intending to listen to music cranked to 11, you really need more power than you might think to actually imitate the dynamics of a live performance."

I say "system" to imply both powerful amplifiers ALONG WITH speakers that can actually handle that power.

Because you can never have too powerful of a sound system, but you can certainly have too powerful of an amplifier.
Even this is a bit inaccurate. While it's true that you can ruin speakers by giving them too much power, it's also very easy to limit an amplifiers output. Just because you have 1k watt of power available to each midbass, doesn't mean that the speaker gets that power. I would argue that you really can't have too powerful of an amplifier, because of how the gain structure works you can easily make the 1k watt amplifier provide an appropriate amount of power.

So yes, you can overpower speakers, but you can also have incredibly powerful amplifiers that will never harm a speaker. This is why people say buy as much power as you can. Running a robust amp at a minimal level can increase the longevity of the equipment vs. running an amp at it's limit.
 

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Oh yeah, I totally agree on that. But I was more refuting the bit about "big amps rarely damage speakers."

I suppose I could have worded it better. ;)
 

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Just read this thru for the second time.
A ton of very good information.

the "turn up the gain until it clips" reminds me of a good 'ole engineer I used to work with, he was from Alabama:
"Tighten it down till it turns easy and then back off half a turn."

Are you out there Capt. Tibbits?????
 

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I agree that if gains are set correctly I don't understand why an amplifier would hurt any speaker that's setup appropriately. But I usually only see people turn the gain up too much when using smaller amps.
Doesn't a coil need to shed heat? If it's busy playing distortion or getting stressed out due to clipping, when will it get a chance to breathe? But I failed to mention my assumption of a poorly set gain.
 
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