# Subwoofer Pulses after 20 min of playing



## AndrewKicker09 (Jun 24, 2010)

Ok so I have a pioneer HU with a MA audio amp HK2000D hooked up to three kicker solo classics 15s. I have a battery in the back that I charge externally with a kinetic battery charger. Its a kinetic 2400 battery. I can play the subs fine for about 10 to 20 min then I get a pulsing from the subwoofers without the beat from the song. I have the battery grounded to the chasis along with a ground from the back battery to the front. I changed the front chasis ground with 0/1 guage along with the front battery ground to the engine block. I dont think its a bad ground. I had it pulsing and I unplugged the rcas and it kept pulsing. I read a little about this and think its refered to as 'motor boating' but not 100% sure. Does anyone have any idea if its the amp or HU? any suggestions please


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## AndrewKicker09 (Jun 24, 2010)

I have the gain at 3/4 up..and the speakers are rated at 700 rms..so i know im only getting 500 for each speaker. would that make any difference..they still sounded good and this happened maybe after 3 weeks of playing and I was breaking them in so I didnt really turn up the HU. I got to 25 at the highest.


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## jaggerwild (May 21, 2007)

AndrewKicker09 said:


> I have the gain at 3/4 up..and the speakers are rated at 700 rms..so i know im only getting 500 for each speaker. would that make any difference..they still sounded good and this happened maybe after 3 weeks of playing and I was breaking them in so I didnt really turn up the HU. I got to 25 at the highest.


 Just back to basic's really make sure the RCA'S are separate from the power and ground cables(I'm sure you know this but) Also make sure the AMP has a properly rated ground and the power cable to it is rated appropriately. If you have a ground loop isolator I'd try it in line with the RCA'S, some head units only give feedback once a certain volume is passed. Pioneer is famous for this, you may want to look at a higher end head unit. They cost more but the pure sound the produce is second to none!


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## AndrewKicker09 (Jun 24, 2010)

Ok they are separate..Im using 0/1 guage for power and ground..I think you might be right about the headunit. I have had it for 3 years now and it might be time to get a new one. What is a top brand head unit for having a subwoofer? Clarion? Your information is appreciated. Thank you again.


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## AndrewKicker09 (Jun 24, 2010)

Another quick question..Do sound processors add any benefit to the sound of the subwoofers?...Or are they just another thing to cause aggravation?


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## jaggerwild (May 21, 2007)

AndrewKicker09 said:


> Ok they are separate..Im using 0/1 guage for power and ground..I think you might be right about the headunit. I have had it for 3 years now and it might be time to get a new one. What is a top brand head unit for having a subwoofer? Clarion? Your information is appreciated. Thank you again.


Eclipse makes some nice ones there not cheap though, as for the sound processor if you have some good tweeters and mids then sure.


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## AndrewKicker09 (Jun 24, 2010)

Well I unplugged the rcas and after playing a cd for about 15 to 20 minutes again...the subwoofers started to make the same doom doom doom tone. The amp was in power mode..was not hot and I pulled and twisted all the connections at the amp and nothing changed. Any ideas what may cause the random doom doom doom even when the rcas are unplugged? Also why would it take 15 to 20 min to start the doom doom doom? Thank you for any information.


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## jaggerwild (May 21, 2007)

AndrewKicker09 said:


> Well I unplugged the rcas and after playing a cd for about 15 to 20 minutes again...the subwoofers started to make the same doom doom doom tone. The amp was in power mode..was not hot and I pulled and twisted all the connections at the amp and nothing changed. Any ideas what may cause the random doom doom doom even when the rcas are unplugged? Also why would it take 15 to 20 min to start the doom doom doom? Thank you for any information.


 Try this,
Even though the main fuse looks good you probably have an extra one, swap it out.
The the woofer did it even though the RCA'S were unplugged? Very weird so this has to be coming from the head unit , there isn't much you can do. Either swap it out, or try putting a couple 120MM fans behind the dash board pointing on the rear of the unit. You could try playing it with the head unit out see what type of temps it reaches when it does this.


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## AndrewKicker09 (Jun 24, 2010)

Ok im going to buy a eclipse head unit i seen that I liked..and pretty reasonable..I wont be able to get it for a couple weeks but when I do and swap it out I will let you know. Yes it was doing it with the rcas unplugged. Im gonna take it out the dashboard and see how hot it gets. I know it gets pretty hot tho. And I will check the fuses too. Thank you again for the input. Its very much appreciated.


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## Aus_Karlos (Mar 10, 2007)

Hi Andrew as an electrician by trade im suspecting a neutral feedback to your sub. Im no expert on car audio or car electronics but having 2 separate power sources (batteries) sharing the same return path will cause problems if their not paralleled with each other. As soon as one of the batteries starts getting a voltage difference between the other your neutral conductors (return path) will become unbalanced can can actually have positive voltage running though the conductor.

I'd suggest linking the batteries with the appropriate gauge wire to keep both batteries at the same voltage/amp level. As both will be charged by the alternator, however please be careful as your current alternator may not be able cope with charging two batteries and could cause it to fail over time. 
So check with your cars manufacture to ensure your alternator can cope.

Edit:
Also ensure that both batteries can be charged together as mixing batteries can be very dangerous.


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