Question about clipping

[Vega 10+ year member]

OK clipping is when your drive an amp to push out more power than it's supposed to right? But I have a question. I have a KX1200.1 the manual states that I should use 1/0 gauge power wire but I already had 4 gauge running. I also tapped into that same power wire to power my LC6. I don't have the big three done and I have the stock battery. So I can't get a full 1200 watts out of the amp but I want to know if it's still possible to clip or overdrive the amp even though the power wire isn't even big enough to get 1200 watts through and the power it is getting is being shared? Just curious.

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[iceteebone 5,000+ posts]

clipping the amp is basically sending out a clipped soundwave or square wave. i assume you set your gains with a dmm? if so this shouldn't be a problem.

 

[Grmanalishi 10+ year member]

Search for clipping in yahoo. Instead of producing a sine wave the wave becomes square:

http://en.wikipedia.org/wiki/Clipping_(audio)

When an amplifier is pushed to create a signal with more power than it can support, it will amplify the signal only up to its maximum capacity, at which point the signal will be amplified no further. As the signal simply "cuts" or "clips" at the maximum capacity of the amplifier, the signal is said to be "clipping." The extra signal which is beyond the capability of the amplifier is simply cut off, resulting in a distorted waveform.
Effects of clipping:

In power amplifiers, the signal from an amplifier operating in clipping has two characteristics that could damage a connected loudspeaker:

* Because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power when it is clipping. This extra power can damage any part of the loudspeaker, including the woofer or the tweeter, by causing overexcursion, or by overheating the voice coil.

* In the frequency domain, clipping produces strong harmonics in the high frequency range. The extra high frequency weighting of the signal could make tweeter damage more likely than if the signal was not clipped. However most loudspeakers are designed to handle signals like cymbal crashes that have even more high frequency weighting than amplifier clipping produces, so damage attributable to this characteristic is rare.

1/0 gauge cable can handle something like 2400 Volts. 1200 W is probably no problem. Microwaves are like 300-700W and they run on 110 V.

 

[Hoodlum007 10+ year member]

Clipping can also occur if you run the ohm load lower then the amp can handle, if an amp is 2 ohm stable and you run it at 1 ohm it will clip in most cases instead of frying.

 

[DanWiggins 10+ year member]

OK clipping is when your drive an amp to push out more power than it's supposed to right? But I have a question. I have a KX1200.1 the manual states that I should use 1/0 gauge power wire but I already had 4 gauge running. I also tapped into that same power wire to power my LC6. I don't have the big three done and I have the stock battery. So I can't get a full 1200 watts out of the amp but I want to know if it's still possible to clip or overdrive the amp even though the power wire isn't even big enough to get 1200 watts through and the power it is getting is being shared? Just curious.

In actuality, the situation may be worsened by using thinner gauge wire!

Wire has a resistance per foot rating, based upon the diameter of the wire. Larger diameter, less resistance. A 1/0AWG wire is ~2.2 times larger in area than a 4AWG wire, so you have roughly 2.2 times HIGHER resistance with your 4AWG wire.

Now, why does this matter? Well, let's say you have a 1200W amp putting out the full 1200W output. At 12V (to keep the numbers easy - I'm lazy...//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif) that would be 100A (P=I*V, I=P/V = 1200/12). So we have 100A of current...

Now, 4AWG wire has a resistance of 0.24 Ohms per 1000 feet; let's say your power run is (again, to be lazy) 20 feet. So we have (0.24/1000*20) 4.8 mOhms of resistance. With 100A running down that, we would lose (0.0048 * 100) 0.48V, or about 0.5V DC drop for your amp.

What about 1/0AWG wire? Well the resistance is 0.096 Ohms per 100 feet, so we have a total drop of 0.2V DC drop to your amp.

That's not a big difference, but it does mean you amp may not be able to fully generate all the output before clipping (the power rails will sag further), and your amp will run a bit harder (longer ON portion of the power supply's duty cycle) to compensate. Both of which don't help.

Add another amp to the equation, so you're pulling even more current, and things get worse...

Is it a fatal flaw? Nope. But something to think about. In your particular case, 4AWG is probably OK. Don't go smaller, though...

Note too that just because your voltage sags so that you could generate "only" 1000W unclipped, that still means that with hard clipping you can still put out nearly 2000W of power!

Dan Wiggins

Adire Audio®