sub pop after shut off

Hello everyone,

I'm in need of some assistance. I just installed a new head-unit (Kenwood KDC-X891) using the proper method of solder and heat shrink so I know its all good there. The problem is when I shut my vehicle off, my sub always makes a pop. Just a single pop every time. Just wonder what this is and how I can prevent and stop it. I'm assuming its a ground issue but I just have no idea where to start.

Any assistance is appreciated. I do realize this has most likely been talked about before but I could not find the answer through the search.

Thank you,

Jon

Thanks for the link. I did check my grounds today and they are all good. Just wondering if anyone has used this product in the past and can give it some positive feedback.

Thanks,

Jon

You want your head unit to delay turning off until the sub amp is off, or the sub amp gain is set too high.  Reprinted here is a response geepherder wrote on this forum to this question.  I saved it to file for reference.

If your gain controls are set too high, this can happen.  This would be the first thing to check.

If that checks out, then many times all it takes is a slight delay to power down the amp before the radio.  What you can do is cut your radio's accessory lead, and install a diode inline (put the stripe side toward the radio).  Now, install an electrolytic capacitor (220-1000 microfarad) on this line after the diode (on the radio side).  The bigger the value, the longer the delay.  Make sure to observe polarity on the cap (it'll pop if you get it backwards)- there'll probably be an arrow with a "minus" sign in it identifying the negative terminal.  Connect negative terminal to ground, and positive to the accessory lead.

Now, when you cut off the ignition, the diode will keep voltage from leaking back into the accessory circuit where the amp is tied on, and the capacitor will discharge into the radio, keeping it on until after the amp shuts off.

geepherder

The Navone product N-66, first on that linked page, will do this.  Or go to Rat Shack for the parts for a DIY build.

http://www.radioshack.com/product/index.jsp?productid=2103627&cp=2032058&f=Taxonomy%2FRSK%2F2032058&categoryId=2032058&kwCatid=2032058&kw=capacitor&parentPage=search

http://www.radioshack.com/product/index.jsp?productid=2062577&cp=&sr=1&origkw=diode&kw=diode&parentPage=search

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.