blowing amps

[Checkers]

Hey guys. Need some help here Before I lose my mind. First the stereo I'm doing is in an 05 cobalt as. The stereo consists of an alpine touchscreen with 4 volt outs ten 6.5" subs with 2 Memphis 1.1200 amps, Memphis sq components, arc audio 6x9's with a Memphis 75x2 on each. Optima battery and 1/0 wire from the alternator back. The problem is I keep frying the small amps on the highs and one 6x9. My battery voltage under full volume is 14 volts and my grounds have a drop of .007 volts. The amps are ask turned down and not clipping. I'm out if ideas on this and any help would be appreciated.

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[winkychevelle 10+ year member]

Add a battery in the back near the amps I bet your voltage is dropping but u aren't seeing it. The alt in that car shuts off periodically for better fuel efficiency which means the amps are sitting at 12.xx volts till the next draw then they drop below 12v and I'm betting the a/b is getting hot really fast and burning up. Which is the reason old a/b sub amps where huge with a crap ton of fins. A/b amps generally get hotter than class d amps

 

[Checkers]

Well the battery is in the trunk and I was checking voltage at the amp itself. I was told these new Memphis amps were class d. They are Lil bitty now too. Should I test the voltage for a longer time to see if it drops down like you said?

 

[jco1385 5,000+ posts]

What's the actual load at the amp, and what is the amp stable at?

 

[Checkers]

4 ohm stereo on each stable to 2 ohm

 

[jco1385 5,000+ posts]

So the amp is 4 ohm stereo and 2 ohm bridged? What do the speakers show at the amp? What I'm getting at is maybe you're running below the rating of the amp. Maybe listing model numbers of the equipment in question, along with your wiring config could help sort it out.

 

[Checkers]

Ok at the amp it reads 3.8 ohm and I'm running it in stereo. The amps are Memphis mr2.240 and I'm just running them straight forward with no bridging

 

[CrossoverOre 10+ year member]

so you keep burning up both amp? how do you have the amps mounted? I imagine the 6x9 is mounted in the rear deck and free air into the trunk. Its possible the subs are forcing the 6x9 do move with the bass notes and causing it to burn up. I have heard some systems where the 6x9's pop like hell when the bass hits and thats no good for life span. not sure why only one would burn up though. how many times has this happened? some pics of the install would help as well.

 

[Checkers]

This is the second time it burnt the amps. They are mounted to the speaker box. I was going thru it last night and the 6x9's def move with the subs. And that's even with the back seat folded down. And yes they are free air in the back deck. I did notice that when the car is cold its holds voltage great.... But after awhile the subs pull it down to the love 12v range while playing. Bounces right back to 14.4 in between bass notes though. Oh and not sure how to post pics. Only have my phone and no computer.