Better is subjective.
Lower db efficiency = requires more power to play at a speaker with a higer efficiency.
I would try to find a speaker with the highest efficiency dB rating if using with the stock system.
I noticed recently, that after driving, and when I turn my car off by pressing the start/stop button, that both the left/right signal indicators on the dash will flash once in parallel to turning off the car.
I don't recall this behavior before last week, so just want to ask if anyone else has...
The harness would carry the signal and (low) power to the unit. Why not just run a new wire from the battery back, and tape into the rear deck?
You would have a much better signal and power supply this way. The box could tuck into the rear right corner of the trunk too.
Did you lower your car? Is the popping sound, sound sound like a knock? a ping? A metallic sound?
Some obvious culprits to check: wheel torque, front strut bolts, and brake shields. Also, check your exhaust to see if it is touching anything (a mirror and flashlight may help).
I had a clank...
The LC2i can only accept 1 set of speaker inputs, meaning you could feed your stock front signal, or your stock rear signal only to your (new) aftermarket amp. You can run it, however 'fade' controls on the car won't change anything. You would run the output labelled MAIN to your amp, and BASS...
There is a TSB for some cars that had a pinhole weld gap in the top right of the body; causing a whistling noise and water to intrude. I don't have the number handy but a quick search for 'whistling' should bring it up.