garrisjs

I installed a Rockford Fosgate Powered Subwoofer (P300-10) to the factory stereo of my 2014 Honda Accord Sport (the amp is inside the sub box).
I used an "AudioControl LC2i" line output converter to connect my rear speakers to the subwoofer via RCAs (I spliced into the rear speaker wires and ran wires into the line output converter box, then ran RCAs from the converter into the sub).
The remote turn-on wire for the sub is hooked into a fuse near the kick-panel on the driver's side..

I hear 4 loud rumbles from the subwoofer when I start my car's engine. It sounds like my sub is pushing a deep bass note for about 3 seconds, followed by 3 short bass "pulses."

I only hear the 4 rumbles when I turn on the engine. When the car is in ACC mode and the stereo is playing, there is no rumble.
Everything else sounds great, but I really need to get rid of the rumble when the engine starts because it is super loud/deep and I worry it will blow the speaker and it scares the crap out of my kids in the back seat.

I've tried MULTIPLE ground locations (trunk bolts, seat belt bolts, etc.) At this point I grounded both the sub and the line output converter to the negative battery terminal. The ground connections are tight. I do not hear any engine hum or hiss or anything like that from the sub. The sound is perfect. It's just the 4 loud rumbles when I start the engine that need to be fixed.

I read somewhere that the voice recognition interferes with the audio sometimes, maybe that's the problem? Either way, I greatly appreciate any thoughts on how to fix this.

Thank you!

hometheaterman

Did you tap into the ignition fuse? This is common if you use the ignition fuse for the remote turn on wire and don't have an amplifier with a built in delay. I've run into this several times before. Use a different fuse.

garrisjs

Thanks for the suggestion. I tried using a few different fuses but I still get the same problem with the rumbles when the engine starts.