TURN OFF NOISE

There is a static that builds on the woofer , check the wiring and check grounding of the woofer once again

Hi,

This sounds like a small line capacitor discharging and amplified by the power amp. Unfortunately, this small capacitor can be anywhere from the head unit, equalizer or electronic crossovers (if any), regular amp (if separate from the subamp) and where the RCA terminated cables from the HU initially goes to and finally the sub amp itself. These could be a 1~2.2uF (or thereabouts) line/series capacitor. Its purpose is to provide a pathway for the audio but block an DC signals. What you are hearing (I suspect) as boom are these capacitors discharging along the audio line.

Corrective measure would be open the units up, performing diagnostic and capacitor test (specifically those that are used as inputs). The best would be with the use of a capacitance meter but an ordinary analog VOM/Continuity tester would also do the job. These capacitors are normally located pretty near the RCA input or output jacks. It is not uncommon also for capacitors in the amplifier to cause similar concerns.

Alternately, a quick and dirty trick to reduce if not eliminate the sound is to install another set of capacitors along the audio line. This could be done at the HU's RCA output or the amp's RCA input. Of course this did not correct the defective capacitors (if any) but merely a workaround.

Another possibility that can not be discounted is that the internal DC to DC power supply of the sub amp is acting. Again main possible culprit could be the big capacitors. Additionally, it could be simply the speaker relays (if present) failing to switch off during power down.

All of the above of course would require that you be familiar with electronic circuitry and components, the use of a DVM and possibly a soldering iron. Should you be uncomfortable with a DIY, perhaps your best bet would be to seek the services of a qualified audio professional.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.

chek your wofer cable is is bed