Whole house surge protection

I have a dedicated power line for my 2 ch audio set up , and just before the main power switch , I have installed Brickwall Surge protection. Model: PW2RAUD .
http://www.brickwall.com/collections/surge-protectors-home-theater-hdtv/products/two-outlet-audio-surge-protector
I have given a separate copper wire running from this Brickwall unit to the backyard , where it is connected to a copper plate ( 12"x12"x1/2") burried at 6 ft. deep below ground ( plus common salt plus coke , water ,to give a good earth or ground ) .
I assume , I have good surge protection for all my equipments.
In last 12 years did not have any problem , but that is no way of knowing!
Any comments , please .

Jea48
I do not quite follow , but I checked with my electrician .
He says : this dedicated line running from main power supply to my audio room has not been connected to any earthing "untill " it is past the main switch in my audio room and then it reaches Brickwall unit , from where the ground pin of Brickwall unit is directly connected to a bare heavy copper wire to the copper plate for ground . Brickwall ground pin is only connected to this dedicated earthing and nowhere else .
Also all power ports in audio room are from output of Brickwall , hence earthing to all audio equipments is also connected to the same dedicated ground copper plate(through Brickwall ) .
If you can share your email , I would like to give to you a Schematic of my connections .
Thanks