QUOTE(nightzstar @ May 20 2008, 02:16 PM)
I see. I just scare will spoil my speaker that why wanna ask advice here

Thanks for da info
Why don't you go to a pro installer who has an RTA (real-time analyzer)? He will be able to tune it based on your installation, i.e., your sound output within the sound stage (car cabin). But pls bear in mind there is only so much he can do, if your equipment has frequency humps all over the place he can only isolate and attenuate to a certain extent, anything above that you may have to change components.