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Amp getting hot?

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Old Jun 26, 2005 | 02:04 AM
  #1  
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Default Amp getting hot?

I just installed two 10" JL Audio W0's wired to Kenwood amp.
I'm not sure of the model number(gotta look at the amp), but
I know that it's from 2004(possibly 03) and it's a mono amp that
handles up to 1000watts. Runs 2ohms...

Ok here's a question. My amp gets really hot after I play music for a bit.
It started to get so hot that I can smell it burning.
So I turned down the woofer all the way to -6, but it's still pretty hot.
thankfully no burning smell tho...

Is it normal for an amp to get hot like that after a while? Or is my amp taking
too much beating from my woofers?
I'm new to subs and amps, so I don't really have a clue what's going on.
The guys that installed it are reputable dealer too...can someone please help?

Thanks in advance.
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Old Jun 26, 2005 | 03:08 AM
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if i were u i will bring it back right away!
no amp will have burning smell!
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Old Jun 26, 2005 | 06:09 AM
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How and where is the amplifier mounted?

The laws of thermodynamics aren't just the law, they're a darn good idea too!

There is little chance that you acually have a one thousand watt amplifier unless it's actually a $1400 Rockford Fosgate or the like. If it's one of those $200 thousand watt amplifiers it's probably poorly designed. If it's one of those $1400 models it will have thermal protection and shut down to protect itself.

For best cooling you want the amplifier bolted to the floor horizonal with nothing to block the air flow. If you want to smoke the thing put in the passenger's cubby hole or under the carpeting under the seat.

Mounted vertically is alright.

Mounted upside down is bad too as most aren't designed to have the heat flow back into the electronic components on the circuit board.

If you're smelling things cooking it's only a matter of time - if you haven't damaged the quality of the circuits already - before something pops. Electrolytic capistors would be my first bet followed closely by the diodes and transistors. As the caps go they'll alter the sound major. When they pop you'll know it as it sounds like an M-80 firecracker exploding.
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Old Jun 26, 2005 | 06:13 AM
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Is it the Kenwood KAC-6151D?

About $240 and I would say about 200 watts to 4 ohms.

Maximum Power: 1000x1 Watts

Maximum Power: The amount of power a speaker is estimated to handle during a brief high-intensity musical burst. Since this can vary with both frequency and amplitude, it is a much less accurate way to judge speaker durability and performance than RMS.

Like saying the maximum speed of my Z is 800 miles an hour. When dropped from a C-17 transport from 20,000 feet the car will reach 800 miles an hour just prior to impact.
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Old Jun 26, 2005 | 06:28 AM
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how are the w0s wired.... wire them into as large a load as possible or turn the gain down on the amp or turn the bass boost down
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Old Jun 26, 2005 | 07:35 AM
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Originally Posted by Paul350Z
Is it the Kenwood KAC-6151D?

About $240 and I would say about 200 watts to 4 ohms.

Maximum Power: 1000x1 Watts

Maximum Power: The amount of power a speaker is estimated to handle during a brief high-intensity musical burst. Since this can vary with both frequency and amplitude, it is a much less accurate way to judge speaker durability and performance than RMS.

Like saying the maximum speed of my Z is 800 miles an hour. When dropped from a C-17 transport from 20,000 feet the car will reach 800 miles an hour just prior to impact.
Paul350z, thanks for your reply. The amp is located at the Rear glove compartment.
I don't believe it's the model that you've stated because I believe
my amp was about $450 mrsp when it came out. It's also a 2ohm amp...
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Old Jun 26, 2005 | 07:36 AM
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Originally Posted by Ahsmo
how are the w0s wired.... wire them into as large a load as possible or turn the gain down on the amp or turn the bass boost down
I have no idea how it's wired sorry-_-;;
How do I turn the bass boost down?
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Old Jun 26, 2005 | 01:41 PM
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Let's see - one watt-hour of electricty produces 3.412 BTUH.

The thermal conductivity of plastic is about 0.190 (and that's not good). The heat fins of your amp are made of aluminum which has a thermal conductivity of 250 watts/meter-C.

Fourier's law of thermal conduction is q=-(k * A * Delta T)/S

q is the heat transfer in watts
k is the thermal conductivity of the material
A is the heat transfer area in square meters
Delta T is the demperature difference across the material is degrees Celsius
s is the material thickness in meters

SO

q is the number of watts that we can expect to transfer into the second thermal trap of the inside of the rear of the car. I am not going to even think about how long you'd have to have the amp up to over heat this much larger compartment.

Using some WASG (wild *** sciencitific guesses)

The k of plastic is 0.190

The A of the cubby hole is about 840 square inches or 0.54 square meters

Figure the temperture difference from a comfortable passenger cabin of 78 degrees F to the manufactures maximum temperture of 110 degrees is 32 degrees F or 25.5 degrees C to 43.3 degrees C or 17.8 degrees C.

The thickness of the cubby is about 0.0075 meters thick.

Plugging this number's in the the good Mr. Fourier's formula gives me:

q = -((0.190)*(0.54)*(17.8)/0.0075 = 243.5 watts worth of amplier power. Most amplifiers are about 50-80% efficient so figure that the actual speaker power of 121 to 195 watts worth of amplifier.

So if you're going to put a larger amplifier than 120-200 watts or so you're going to run the temperture of the cubby hole beyond the maximum recommended operating temperture.

So venting that heat to the outside is critical. Open the bottom of the cubby up with a series of large 1.5 inch holes on either side of your amplifier. Cut as many matching ones above the amplifier. If you can use forced air cooling with a small 80 cm computer fan mounted above the cubby to pull about 20-30 cubic feet of air per minute across the amp.

Think about a room space heater running 1500 watts - sure heats up your entire room pretty well - you're dumping that same thermal energy into the little cubby hole.
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Old Jun 26, 2005 | 11:44 PM
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Whoa Paul350z, that's some serious math calculations there!
Well I understand what you're trying to say.

Ok here's accurate stats of my system.
My Amp is Kenwood KAC-X520
http://www.carreview.com/cat/car-aud...4_1806crx.aspx

And it's powering 2 10" JL Audio W1 V2's

The amp is heating up like crazy and the bass hits WAY too hard..even at lowest possible setting.

I'm thinking about getting a 4-channel amp cuz my rear speakers sound horrible, and also relocating the amp to back of my bass box.

Also I'm thinking about just going with a single 10"...as of now 2 10"s are
overkill for my car.

But all this will add more cost=(
I've already spend over $2500 on a system, and I'm not happy about it

Oh btw, I have same headunit as you do, AVIC-N2
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Old Jun 27, 2005 | 06:05 PM
  #10  
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(243.5 watts) / (1 - the efficiency of the amp) = 243.5 / (1-0.80)
for a class D amps
your new calculation would be 1217.5 watts

put a computer fan in there to get the air moving and a way to get it out and you should be fine
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