Thumping Sound When Turned On/Off

[rzj90059 10+ year member]

Ok I have no idea how to remove it, whenever I turn on my car on or off with the stereo on it makes a loud thump. But if I turn off my stereo before i turn on/off the car, theres no thump.

One more thing, i just added a second battery in my trunk, and its hookep up to the front batt with a 1/0 run and ground to the chassis, Im a lil concern if its safe without a fuse between the batts. Its my first time doing this so any expert's input is appreciated. I also have my stock alt installed. Will any of my electrical components be harmed.

I am trying to accomplish to keep my voltage at 14.4 stable so i can put out 1950rms, because if not at 13.8 it will be 1300rms. Will these two batts keep it stable???

I have some auto zone batt in the front (not actual auto zone batt, just bought it there) and a red top in the back.

All your guys' inputs is appreciated.

-Roger

Click to read more...

 

[rzj90059 10+ year member]

Oh an this is in a 1969 Nova

 

[CJL 10+ year member]

What kinda HU do you have?

 

[rzj90059 10+ year member]

I Have a Pioneer Premier DEH-P90IB

 

[phyphoestilic 5,000+ posts]

could be a ground loop. Or ur amp just doesnt have a delay start.

 

[gl0ck 10+ year member]

Try a 1000ohm Resister inline on the remote turn on.

 

[CJL 10+ year member]

I Have a Pioneer Premier DEH-P90IB

I was hoping you had a Pioneer, Ground the RCAs to the HU as seen in THIS THREAD, That fixed every single noise(i had alot) with my Premier DEH-P590iB.

 

[rzj90059 10+ year member]

Ok lets try to most inexpensive way right now

lets start with ground the RCA's, how do i do that

Then the resistor thing

 

[phyphoestilic 5,000+ posts]

Ok lets try to most inexpensive way right now
lets start with ground the RCA's, how do i do that

Then the resistor thing

There's a picture in the thread he linked u....

 

[rzj90059 10+ year member]

Ok got it, how about for my other questions

 

[phyphoestilic 5,000+ posts]

bat's dont really keep stable above 12.8v, u can only accomplish a stable 14.4 with an alt that puts out 14.4, BUT at the same time still provides enough power for the current draw from ur amp + all ur regular car electrionics. So in other words, it wont be possible for any stock amp to put out that kinda current for an amp that puts out 1900rms

In other words u need an alt that puts out at least 135 amps+ w/e ur regular electrionics take up and keep ur engine idle that the point that it puts out that power to keep a constant 14.4 for ur amps.

 

[rzj90059 10+ year member]

no well its not one amp its actually two

MTX 81000D

MTX 8302

 

[rzj90059 10+ year member]

Well If I Cant Get It Stable Without A Different Alt, Then 1300w Rms(2 Amps) Will Do

 

[rzj90059 10+ year member]

Alright you guys ill take a look at this tomorrow in the morning, but for those who have and will answer my question, thanks

 

[phyphoestilic 5,000+ posts]

main point is u need an alternator that can put out enough current for the amps + all ur stock electrical components to be able to keep a steady 14.4v. Also thats saying if u keep ur RPMs at the point where the alt puts out that power.