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VW, Memphis Amp getting hot

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=80129
Printed Date: March 28, 2024 at 4:48 PM


Topic: VW, Memphis Amp getting hot

Posted By: davedyer79
Subject: VW, Memphis Amp getting hot
Date Posted: July 10, 2006 at 9:24 AM

Hello, I installed a Panasonic head unit, Memphis amp (500D) and a Memphis PR12 DVC in a Memphis slot ported box in a 2003 VW Passat this weekend.  I just looped the coils together and into the left side of the amp.  For some reason I keep blowing subs (frying the coil, therefore when  you push on the speaker it doesn't move) and the amp stays REALLY hot.  I have installed numerous of these setups in cars and have never had this problem.  I replaced the amp twice and the sub 3 times.  I have tested all the connections repeatedly with a DMM, all meter correctly.  Has anyone ever had this problem with a Volkswagon, or is it me.  The ground is only 2 ft long, all power leads are 8 guage, 50 amp fused.  Advice would be appreciated.  Thanks, David

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davedyer79



Replies:

Posted By: aznboi3644
Date Posted: July 10, 2006 at 6:26 PM
Is your gain set correctly???




Posted By: 12vdeej
Date Posted: July 10, 2006 at 7:00 PM

As far as im aware most/all amps these days have DC protection, but the situation you are describing sounds just like that to me. Any DC offset present within the audio signal will cause the voice coils to heat up rather than producing noise, leading to failure as you described. It would also cause the amps to get hot. If you can, test the output of the head unit to see if there is any DC voltage present within the output signal. Seeing as this is the only component that didnt get replaced it could have been the culprit. Also double check that you arent somehow short circuiting the output of the amp as this would lead to the same overheating problem. The suggestions i have made are unlikely situations, but are the only ones i can think of! As aznboi3644 suggested, turning the volume up too much will fry your sub, but thats so obvious its almost insulting !posted_image





Posted By: aznboi3644
Date Posted: July 10, 2006 at 8:04 PM
Lol...well some people overlook the most obvious.




Posted By: davedyer79
Date Posted: July 11, 2006 at 8:26 AM
Well, I checked all the connections again, 13.8volts at 12V, good ground, no junk at RCA and no DC/AC going to the subwoofer.  I wonder if I have the connection to the amp correct.  The Memphis 500D is a mono-block amp.  I just daisy chained the two coils together to a 2 ohm load (DVC 4 ohm) and tied them directly into one channel of the amp.  Should I have used the outside connections + and - ( I guess bridged mode, but you cannot "bridge" per say this amp).  Could a ohmage issue cause this amp to overheat??  The Memphis tech said I am pushing too much to the subwoofer, therefore blowing it.  I guess I can understand that.  I have pushed more wattage than this to these subs before with no problems.  But that doesn't explain why the amp is getting so hot.  Thanks so far for the suggestions. 

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davedyer79




Posted By: aznboi3644
Date Posted: July 11, 2006 at 11:08 AM
You cannot bridge the amp...It only has two sets for easy wiring.

I looked at the site for those subs and the rms rating is 250 watts rms correct...Well at 2 ohms your pushing 500 rms to that sub...Have you not realized that is more power than the sub can handle?





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