Recently my monoblock spoiled. Get a 2nd hand monoblock (black general) FOC from friend.

After installed. when on/off the HU, it have a little 'pop' sound on the woofer.

Installer said that because the old version of monoblock doesn't have the soft turn on/off feature. (some kind of relay thing).

Anyone know how to solve ? will the woofer spoil ?

Before turn off the car.. try to pause and then off it and see.. if still got sound.. then really dunno what to do

it still the same. I think just gonna let it be.

Now got another problem.

if I mute it, when aircond kick in, can hear abit of whining noise. then after awhile, it goes off.

But the noise doesn't go loud if u accelerate the RPM higher. (sound come when aircond kick in).

This means that if u turn on the music louder, then u won't hear it anymore.

Is this to do with the grounding cable ?

I understand that if the whining noise goes loud when u accelerate, then is grounding issue.

Any sifu can advice ?

Either your grounding or wiring bro.. bring to any good acc shop and check bro..