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one amp smoked, new amp cuts out and rest

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=122260
Printed Date: May 03, 2024 at 6:51 PM


Topic: one amp smoked, new amp cuts out and rest

Posted By: develguy
Subject: one amp smoked, new amp cuts out and rest
Date Posted: June 11, 2010 at 2:59 PM

Here's what I have:

Alpine 1/2 channel - 2x12 Alpine Subs
Alpine mrp-f240 4 channel - Front and backs
Car PC
Fused dist block splits to the three

My 4 channel cut out and I found the fuse popped. Replaced the fuse, magic smoke!

Took a look inside the amp and found a component fried.

Picked up a new 4 channel (Alpine mrp-f300), went on a road trip and the new amp cut out and back on twice in about three hours.

The sub amp was still playing when both 4 channels cut and the car pc still was running. Tunes were cranked both times.

This happened again today, on the highway, tunes cranked, A/C cranked. Could my alternator be struggling to keep up causing the amp to bailout? Why aren't the pc or the sub amp crashing?

Any ideas on what to check here?

Thanks!



Replies:

Posted By: topinstaller200
Date Posted: June 11, 2010 at 3:40 PM

Well everything comes into play here

The quality of your installs( Did you run all your wires properly thru the firewall with a grommet of thru factory rubber where there is no chance of the wire shorting to metal? or did you run the power wire thru the door jam? Are you using the proper size wire for both power and groung connections? Did you upgrade your factory ground wire between battery and frame? Are you usind the correct fuse rating? Are all off your wires properly terminated and insulted?

Is there any panels you removed to run wires and replaced with screws? Is there any chance you could have driven a screw or clip into your wires and shorted them out?

Are your amps securely and properly mounted?

Is any of your equipment exposed to moisture or excessive heat(ie; bad trunk gasket that might leak)

Are you exceeding the Ohm load capacity of your amplifier?

Lets start with these questions before we go further. I am thinking your issues are related to one or more of the questions I asked you.

For future reference. If you ever have an amplifier that FRIES do not replace with new one with replacing your Power wires. Never us used wire. Like if you get a new car and want to install your old equipment then make sure you buy a new amp kit

Good luck! Don





Posted By: bloob
Date Posted: June 11, 2010 at 10:26 PM
topinstaller200 wrote:

. Never us used wire. Like if you get a new car and want to install your old equipment then make sure you buy a new amp kit

Good luck! Don





i've never heard that before. could i ask why? and then let me make this observation.
my 4 gauge wire from 5 years ago is wire strand thicker then the 4 gauge is now..
(and actually ive had 3 different amps attached to this particular wire, damn good wire lol)




Posted By: forbidden
Date Posted: June 13, 2010 at 3:16 PM

develguy wrote:



My 4 channel cut out and I found the fuse popped. Replaced the fuse, magic smoke!

Took a look inside the amp and found a component fried.

Picked up a new 4 channel (Alpine mrp-f300), went on a road trip and the new amp cut out and back on twice in about three hours.

The sub amp was still playing when both 4 channels cut and the car pc still was running. Tunes were cranked both times.

This happened again today, on the highway, tunes cranked, A/C cranked. Could my alternator be struggling to keep up causing the amp to bailout? Why aren't the pc or the sub amp crashing?


Fuses pop for a reason, never ever replace a fuse without finding the cause of it or you can almost guarantee magic smoke.

The big thing I see here is simple. It is hot out, ac or not. Your amp is a class AB design, it is going to get hot, it is designed to get hot. What makes matters worse is how you are using the amp. The big parts of your quote above that are smacking you upside the head and saying "dude wth" is "tunes were cranked" and "three hours".

The problem here is that the longer something is used, the more heat that builds up. The louder something is played, the more the heat that builds up. Your amp is having the equivalent of a thermal heart attack. Your combination of playing for 3 hours + cranked is going to spell SMOKE again in the future. An amp must be allowed to cool. If the amp gets too hot the thermal shutdown is going to engage as it did in your case that you mentioned in the 3 hour time frame. Ensure that you have a above average ground, this does not mean to the closest amount of sheet metal with no paint on it, it means go and find the what is a proper ground sticky and follow through on it. Ensure that your amp has the right guage of power and ground wire for the application before you cause it to have a heart attack.

A bad speaker or speakers is another possibility, all that power for that period of time may also have killed Kenny (Kenny being your speakers). If you have a speaker that plays fine at lower volume but all of a sudden sounds like a dead cat getting nailed by a Kangaroo at top volume, the speaker will cause the amp to do all sorts of wierd things. A speaker and an amp must be allowed to cool. DO NOT play them for extended periods of time without allowing them to cool, never mind the damage that your ears are receiving. A sub pounding away is going to mask the distortion coming out of the other sets of speakers. Play the system one day without your sub running so that you can accurately listen to the other speakers to see what is going on with them. Play all sorts of different music the same way you play it now, just no sub.

If long and loud is what you are indeed after, a full range class D amp for the front and rear speakers is going to be in your future. Eclipse, Alpine, Pioneer, JL Audio and others all have a new generation of amplifier for this very purpose.



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Top Secret, I can tell you but then my wife will kill me.




Posted By: develguy
Date Posted: June 14, 2010 at 8:34 AM
Thanks for the quick and thorough responses.

Based on your thoughts, I am going to suspect that power and heat are going to be the primary issue here. I am going to do the big 3 upgrade, re-route the grounds and look into a better way to keep the gear from getting too hot.

I'm wondering if there is a mobile audio solution for monitoring the voltage at the amp and the temp around the components.

Thanks again.




Posted By: forbidden
Date Posted: June 14, 2010 at 12:40 PM

Dakota Digital makes temperature guages that may be used for the amplifier. For the speakers though, this is not going to be easily done as the heat that is built up is inside of the speaker itself (this is why voicecoils or voicecoil formers melt).



-------------
Top Secret, I can tell you but then my wife will kill me.





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