What exactly is the Harman Kardan sound system

[hrissim]

Originally Posted by ninaandphil

Go for it... it's a big improvement on the original set up, and although it might look difficult at first glance, it will be worth it. I don't find the sub intrusive in the boot, but would recommend damping it with some sound deadening material, it improves the quality of the bass from what is essentially a plastic box! And quality speaker boxes are not made of plastic!

Recommend some with a link /ebay, amazon if available/, please!
Also some tutorial/technology how to will be good too.
I have plastic thing HK sub woofer fitted.
Where within the car is essential to sound deadening? Areas?
Thanks!