system cutting off
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=118274
Printed Date: May 14, 2025 at 2:45 PM
Topic: system cutting off
Posted By: pcana11
Subject: system cutting off
Date Posted: December 06, 2009 at 10:12 AM
I have finally got my 12w6 installed in my custom ported box, but when i turn my volume up after long periods of time it will cut off and i have to let it set for a while for it to come back on. I am running an Alpine mrp-500 watt amp with 4 gauge wire throughout my truck and 12 gauge from the speaker. Any suggestions? And also, i just wrapped my box in vinyl and i was wondering if there was a cap or something else i could buy to fit around the port to clean it up a bit?
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Replies:
Posted By: i am an idiot
Date Posted: December 06, 2009 at 10:32 AM
Is the amp so hot you can not keep your hands on it when it shuts off? What is the impedance at the amp?
Posted By: pcana11
Date Posted: December 06, 2009 at 10:38 AM
no, the amp doesnt shut off. its wired parallel and its a dual 4 ohm sub
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Posted By: pcana11
Date Posted: December 06, 2009 at 10:51 AM
my bad, it doesnt completely turn off, the light doesnt go off, the amp stays on but quits playing. its not hot or anything when this happens
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Posted By: i am an idiot
Date Posted: December 06, 2009 at 10:59 AM
I think that there is low voltage protection in that amp. You need to check the voltage on the power and ground terminals of the amp when it is playing at the level in which it cuts out. You must use the power and ground terminal of the amp when testing the voltage.
Posted By: pcana11
Date Posted: December 06, 2009 at 11:05 AM
alright, thank you. i will try that today. What would you suggest if there is a voltage drop?
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Posted By: pcana11
Date Posted: December 06, 2009 at 8:39 PM
the reading at my amp is 14.76. whats something else? -------------
Posted By: i am an idiot
Date Posted: December 06, 2009 at 8:49 PM
Were you playing the amp at high volume when you checked the votage?
Posted By: pcana11
Date Posted: December 06, 2009 at 8:54 PM
no i was not, didnt think about that
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Posted By: i am an idiot
Date Posted: December 06, 2009 at 8:58 PM
Playing it at half vomume will not show you anything. It must be playing at capacity to bull as much current as it can. No current draw = no voltage drop.
Posted By: pcana11
Date Posted: December 06, 2009 at 9:05 PM
alright, ill check that tomorrow and see what it is turned up. what could i do if it is a drop. would the big 3 help. my lights are also dimming a little bit.
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Posted By: blackcivichatch
Date Posted: December 06, 2009 at 11:11 PM
Yea, I Jus got the MRP-M1000 and it shuts off for a couple seconds when the voltage drops too much. The big 3 would help you for sure.
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UNLABELED Custom Car Club President
Posted By: oldspark
Date Posted: December 07, 2009 at 4:23 AM
pcana11 wrote:
the reading at my amp is 14.76
The DC voltage reading at your amp input is 14.76V????!!
That is too high for a 12V lead-acid battery system unless you are powering straight off the alternator etc.
If 14.7V is when charging, you probably have a bad ground (ie, engine to chassis) else a faulty regulator. (Unless the system is set up for normal "above 14.4V" operation.)
Or a power diode in the alternator may have failed in short circuit mode, passing AC onto the (up to 14.4V DC) supply.
Or - especially if NOT charging - it may be an SMPS amp hence requiring a true-RMS voltmeter. (Sorry - I have limited knowledge of what the different amps and components have or are.)
Posted By: pcana11
Date Posted: December 08, 2009 at 7:06 PM
what can i do because of the voltage drop. i dont wanna go with a new alt or battery
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Posted By: i am an idiot
Date Posted: December 08, 2009 at 7:33 PM
Did you ever confirm that the voltage was dropping at the amp? What brand of multimeter are you using?
Posted By: pcana11
Date Posted: December 08, 2009 at 7:39 PM
no, i havent been able to due to the rain but my lights are dimming also and i was just gonna go ahead and guess that it is. cut off after two hits from lil jon today. its a fluke meter -------------
Posted By: boxhead78
Date Posted: December 08, 2009 at 9:04 PM
your amp don't have a built in fan so it will cut off when it gets hot
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boxead78
Posted By: pcana11
Date Posted: December 11, 2009 at 11:38 PM
the voltage is dropping from 14.4 to 13.6
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Posted By: j.reed
Date Posted: December 12, 2009 at 12:01 AM
That sounds like a pretty safe drop and nothing to worry about if you are playing it hard. Are you? Not sure on that amp, but Im pretty sure it would not shut off unless it went under 12 volts for the voltage protection. If everything was fully charged before this test you might have to play it a while to take the hit to the batt and alt like you might have been seeing on the road. Another thing is, things like heater running, lights, ect. will pull juice and could account for you not getting the same results you do on the road. ------------- 
Posted By: i am an idiot
Date Posted: December 12, 2009 at 7:34 AM
When you checked the voltage, where did you have the black meter lead? On the terminal of the amp, or on the chassis of the vehicle?
Posted By: pcana11
Date Posted: December 12, 2009 at 9:08 AM
it was on the terminal. and i get what your saying reed, ill try it after i ride around for a while and then stop and check it. but the amp has never over heated so that couldnt be the problem -------------
Posted By: j.reed
Date Posted: December 12, 2009 at 12:34 PM
While you play it hard and longer it will cause your voltage to drop more. If the charging system is to blame. When you are drawing more than the alt can take it starts pulling the extra from the batt. When it starts getting a little lower on batt power you will see a larger voltage drop, especially with other thing pulling current. That could explain your problem of shutting off. Turn everything you can on. lights, wipers, cell phone charger, ect. Anything that could be on during a drive. -------------
Posted By: pcana11
Date Posted: December 12, 2009 at 8:24 PM
alright, ill try all that tomorrow, i only have a 95 amp alt.
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Posted By: pcana11
Date Posted: December 15, 2009 at 5:28 PM
now my w6 is starting to make a popping noise whenever it cuts off. whats the problem -------------
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