Viewing: overheating amps

**Greg160** · 28-03-2009, 02:51 PM

I cant even begin to describe how I feel when just after 30minutes of listening to tunes my amp cuts out and goes into thermal protection.It is a Jec 1200 watt amp with 5 channels, Running 2Kenwood KFC-W3010 1000watt subs,2kenwood mids and 2 pioneer tweeters.You guys probably never heard of these amps but ther very common around here.Their cheap and give good sound quality.So any help would be highly appreciated.thanks

**turbonutter69** · 28-03-2009, 04:56 PM

Does it do when the engine is running? Sounds to me like the amp isn't getting enough power...
Could you explain in a bit more detail buddy. How is it wired up? How long have you had it installed?

**turbonutter69** · 28-03-2009, 05:00 PM

Is it the CA-3247 model?

**Greg160** · 28-03-2009, 05:46 PM

Im not sure of the model right now but i will check it out and let you know.I had it installed in 2006 behind the rear seat but after the over heating i took it out and tried to connect it directly to the battery in a place where ventillation would not be an issue but still the problem persisted.I then re-installed my old amp(a jec 600) which never gave me any problems.The subs were connected in parallel.I was using 4gauge wire for the positive and ground connections.the speaker wireing was done with some wire we call here oxygen free wire.Its wrapped in a clear silicone like housing.let me know if you need any more details.

**turbonutter69** · 29-03-2009, 01:35 AM

Do you know the RMS watts for your sub? I know you said it's a 1000watts but that is max power and not normal running power which is RMS. I don't think it's over heating myself I think it cannot deliver enough power to the subs which is causing it to shut down. It could also be that your battery isn't providing enough power for the amp itself. Does it only do it when you have the stereo turned up or does it do when on low as well?

**Greg160** · 29-03-2009, 05:45 PM

Yeah the amp is the CA-3247 model.The RMS for the subs is 200 watts each.It only does this when the volume is high,when your really driving the amp.I guess if it is at a lower volume it takes longer to heat up.I also tried just running the mids themselves with the amp but it still brought about the same problem.The amp gets hot.I tried putting a wet cloth over it as it was running,and i it was ok.It would get hot but it would not shut down.What do you think?

***HDi fun*** · 30-03-2009, 12:07 AM

If it's shutting down under modest use then there is a problem with thermal runaway. MOSFETs are immune to this unless there is a shorting problem.

Bipolar arrangements do struggle when there's only a differential of 12v between +ve and -ve rails.

**turbonutter69** · 30-03-2009, 12:28 AM

Quote:

Originally Posted by Greg160

Yeah the amp is the CA-3247 model.The RMS for the subs is 200 watts each.It only does this when the volume is high,when your really driving the amp.I guess if it is at a lower volume it takes longer to heat up.I also tried just running the mids themselves with the amp but it still brought about the same problem.The amp gets hot.I tried putting a wet cloth over it as it was running,and i it was ok.It would get hot but it would not shut down.What do you think?

A wet cloth in my opinion would not make any difference what so ever. This to me really sounds like the amp is not getting enough power. Or the amp itself cannot deliver enough power? I would say you need to upgrade your amp.

**c130fxr** · 30-03-2009, 12:53 AM

Try running your subs in a series instead of parrallel. Its sounds to me that your amp is not stable to a 2ohm mono load. It may be stable to a 2ohm stereo load which doesn't draw as much amperage as the mono load. Less amps means less heat.

**turbonutter69** · 30-03-2009, 01:02 AM

Quote:

Originally Posted by c130fxr

Try running your subs in a series instead of parrallel. Its sounds to me that your amp is not stable to a 2ohm mono load. It may be stable to a 2ohm stereo load which doesn't draw as much amperage as the mono load. Less amps means less heat.

Yes that could cause the problem. Check that your amp can run at 2ohm stable. If not then you need to rewire just like c130fxr said.

***HDi fun*** · 30-03-2009, 01:36 AM

Serial connection of LF drivers will lead to problems with damping and inductive reactance.

DC resistance differs greatly from impedance.

Output stages of power amplifiers will always work best when connected directly to one driver only.

It is for this reason that I bi-amp my home hifi - one set of output transistors to each linear motor (speaker)

**c130fxr** · 30-03-2009, 01:58 AM

Funny i didn't have any problems with the 3 12's i installed in one of my comp vehicles I had 2 2 ohm svc subs run in a series to get 4ohms and the third was a 4 ohm svc which i ran parrallel with the other 2 so that i could get a 2ohm mono load for my amp. I was able to beat that setup to death and get around 147 db's. It was still playing just as strong when I sold the van.

**turbonutter69** · 30-03-2009, 10:13 AM

I run my 2 12's in parrallel to get a 2ohm stable load and I can crank it up as loud as I like with no problems what so ever. I also run Vibe's qb69's off an amp with no issues either.

**Brabus SL** · 15-04-2009, 01:44 AM

Check and see if you are not over driving the input of the amplifier, what is the pre amp out voltage of your head unit and the line level input of the amplifier, you could be over driving the input of the amp, most people make the mistake of turning the gain up on their amps to the max which is not the necessarily the right thing to do!
check the pre amp voltage specification of both the head unit and your amps.

**turbonutter69** · 21-06-2009, 07:08 PM

Any news on this buddy. After having a think I would say it's your headunit that is causing the problems.

**PakoMotors** · 30-06-2009, 12:01 AM

always check your ground and power wire it normaly helps to cut the end of the poer wire of at the abtery and re expose a new bit of the wire a cleaner connection

**Greg160** · 03-08-2009, 01:17 PM

Well thanks for all the help with the amp guys but i already sold it off as it was. I dont think the connections were the problem. I think it was something internal.It would just keep cutting off after getting hot.I think it could be the mosfets.

**turbonutter69** · 03-08-2009, 01:42 PM

Quote:

Originally Posted by Greg160

Well thanks for all the help with the amp guys but i already sold it off as it was. I dont think the connections were the problem. I think it was something internal.It would just keep cutting off after getting hot.I think it could be the mosfets.

Mine used to do that but all it was in the end was that the amp couldn't supply enough power to the speakers so it went into safe mode. Nothing wrong with it. It was just being driven too hard.

**dpsubaru** · 04-08-2009, 05:14 PM

One of my amps does the same thing, 1/2 hour only and it overheats - is so damn hot you cant touch the thing.

**Greg160** · 27-08-2009, 04:20 PM

Quote:

Originally Posted by turbonutter69

Mine used to do that but all it was in the end was that the amp couldn't supply enough power to the speakers so it went into safe mode. Nothing wrong with it. It was just being driven too hard.

dude so what did you do to sort out the problem?????

**turbonutter69** · 27-08-2009, 05:16 PM

Quote:

Originally Posted by Greg160

dude so what did you do to sort out the problem?????

Bought a class D amp to run the 2 subs and used the original amp to run a set of 6x9's. And also added a power cap too.

**jonnyb** · 23-09-2009, 11:35 AM

i had the same problem and it was a brand new amp i have taken it bk now so it dont matter