Amp keeps cutting out
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=89541
Printed Date: May 21, 2024 at 5:02 AM
Topic: Amp keeps cutting out
Posted By: 05z71crew
Subject: Amp keeps cutting out
Date Posted: January 25, 2007 at 4:30 PM
I posted this a LONG time ago, but I recently got a new vehicle so I am revisiting my problem. I just put my amp and subs into a new car, using a new box, new amp kit, and an aftermarket headunit. When I turn the amp up it cuts off. My amp is rated CEA at 900W RMS @ 2 ohms while my subs are rated @ 300W RMS @ 4ohms. I have them wired in series to two ohm load. Why would my amp be cutting out? Shouldn't the subs be distorting before the amps quits. Also, it shuts off for about 30 seconds and then turns on for about two minutes then cuts off again. I have to really pound the subs for about five or so minutes before it first starts. The gain on the amp is about half way up, the head unit volume is just over half I think with the sub out all the way up, and the remote boost on the amp is also at full. The subs sound great until it cuts. ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Replies:
Posted By: xtremej
Date Posted: January 25, 2007 at 4:37 PM
It sounds as if you are over-driving the amp and its going into thermal protect. I recomend turning the bass boost off, then set the gains properly without any bass boost. Also verify with a meter that your subs are in fact wired to a 2 ohm load. You may also wish to post brands and model numbers, the more specific the better.
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Posted By: 05z71crew
Date Posted: January 25, 2007 at 4:39 PM
Sorry wrong button... Could the problem be that I am somehow still clipping the amp? If so, how? The subs are underrated for the amp IMO, there is no detected clipping until the amp just stops... If my math is correct, since my subs are in series I still only need 300W RMS to drive them happily. If I did need 600W (Please explain why) I am still only using 2/3 of the RMS rating of the amp.... Shouldn't the subs blow before the amp senses anything wrong? ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: 05z71crew
Date Posted: January 25, 2007 at 4:40 PM
2 12" powerbass s-12 SVC Kenwood KAC-9152D Thanks for anyone's and everyone's help. ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: xtremej
Date Posted: January 25, 2007 at 4:43 PM
Some subs are underated some amps are over-rated depends on the brand. Is the amp warm when it stops. I would still recomend setting the gains without the bass boost on, if they are set properly to match the volume of the rest of the stereo bass boost shouldn't be needed.
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Posted By: xtremej
Date Posted: January 25, 2007 at 4:50 PM
Well I can't say anything about the kenwood amp but I know the subs are pretty durable. We have tested powerbass equipment in house and found it to be pretty tough. The only experiences I have had with kenwood were years ago and they had heat issues. Someone else will chime in that knows more about those amps than I.
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Posted By: DYohn
Date Posted: January 25, 2007 at 6:38 PM
Turn OFF that bass boost. Leave it off. Set your gain properly. What is your voltage level when the amp shuts off? ------------- Support the12volt.com
Posted By: 05z71crew
Date Posted: January 25, 2007 at 8:13 PM
I am not sure of the voltage level, there is no guage in my instrument panel. I was driving down down the road doing roughly 50 MPH when it cut out. Why would the amp go into thermal protect though? I am not using the full potential of the amp (htat I can tell). My whole problem is I had an American Bass amp rated at 1/4 of this amp that would play all day. Now I supposedly step up to a beefier amp that won't even play for twenty minutes before it wimps out. If I were to set the gain properly I would only turn it down maybe 1/8 of a turn. I know the voltage of the outptus of the HU are 2.2 volts. I have the gain set roughly at 1.5 volts. The way I see it I should have plenty of amplifier headroom to be able to set the gain to wherever I want and the amp should blow the subs before the slightest hint of overheating takes place. Am I wrong in thinking this? Shouldn't an amp whose RMS is rated for over three times the RMS of the subs play all day? ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: 05z71crew
Date Posted: January 25, 2007 at 8:18 PM
There is no volt meter in my instrument cluster so I do not know the voltage before it cut out. I was doing about 50 MPH down the road when it started cutting out. The amp shouldn't even come close to any type of overheating,clipping, or anything like that as far as I can tell. The amp's RMS is rated for three time the RMS of the subs. Is that not enough amplifier headroom? ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: 05z71crew
Date Posted: January 25, 2007 at 8:37 PM
If you search for posts I've made you can find the other threads I started. I know the ground is good i took a dremel tool and ground all the paint off of one of the studs my seats bolts too. It is a brand new amp kit. No PAC part anymore. It is a Sony aftermarket HU I got from BestBuy. I don't believe it is a voltage problem because I know the voltage drops way below 12 volts even at half power because I have bass CD's I listen to and the bass notes play for ten minutes. IMO I think this Kenwood amp is just not what it is cracked up to be. ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: aznboi3644
Date Posted: January 26, 2007 at 12:08 AM
Those Kenwoods are pretty tough...I've put a 9102D through a beating and it never stopped. Get a DMM and measure the voltage when the amp cuts out.
Posted By: 05z71crew
Date Posted: January 26, 2007 at 1:05 AM
I have yet to be able to put this one through a beating. Doesn't a vehicles RPM's drop when the voltage goes below twelve? I have never noticed the engine bog down. The amp just...quits. ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: DYohn
Date Posted: January 26, 2007 at 4:44 PM
I'll say it one more time: your subs are wired wrong or your gain/boost is too high or your vehicle voltage is too low, or some combination of all three. Get some help from a pro in your area if you don't want to listen to us. ------------- Support the12volt.com
Posted By: 05z71crew
Date Posted: January 26, 2007 at 6:11 PM
Then why was the voltage not too low for the previous amp? Why was the gain not too high? All solutions coming from this forum have been operator error. Is it not possible that I have a bad amp? I don't want to sound like I am not listening but in my experience listening to the two amps I have, the lesser one played just as loud, longer and with much less heartburn... ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: DYohn
Date Posted: January 26, 2007 at 8:18 PM
Of course it's possible you have a bad amp, but it is impossible to know that until operator error is eliminated as a possibility. Based on what you have posted you have not installed and set it up correctly, and the symptoms you describe indicate you are over-driving the amp or not powering it correctly. No two amps are setup the same way, you can't compare one to the other by just slapping it in and hoping for the best. Install the gear correctly and then see what happens. Or, if you insist the amp is bad, take it back where you bought it and get it checked. ------------- Support the12volt.com
Posted By: 05z71crew
Date Posted: January 27, 2007 at 12:47 AM
So let me get this straight. These are my possibilities... A. All this trouble is because I have the gain set 7/10ths of a volt too high? B. Or I wired two 4 ohm SVC subs to a two ohm load and it is too low for a 1 ohm stable amp? C. Or the voltage in my car drops below 12 volts and the amp shuts off... A I find hard to believe because I would certainly not be the only one with this problem because I am fairly certain at least 100 people who have this amp have the gain set much [too] higher than me... B while possible is not very likely due to the stringent nature of manufacturing of products C Like A is hard to believe as well. If the voltage drops were causing it the everyone who owns one has upgraded the top three, and added a HO alt or 2nd batt to their setup. If I do turn the gain down I will just turn the HU up so I can still listen to the subs at the level I want and have the amp cut out. Or never turn it up and not enjoy the amp or subs at the volume that 2 12's pushing 300W apiece should be able to do. ------------- lil nicky
06 Elantra (No more z71)
2 12" powerbass subs; 6x9's and 5 1/4's
Kenwood KAC-9152D
American bass SQ540
Posted By: DYohn
Date Posted: January 27, 2007 at 11:34 AM
Like I said, then take it back where you bought it. ------------- Support the12volt.com
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