V50 Sound system questions

[rustyveedub]

Hi all,
I have a 2005 V50 Se Sport which i think has the High perforance audio as it has Sat Nav?

What is the difference between this and Premium audio?

As i have seen this clip on Youtube and can see that he has a sub that can be controlled from the head unit. I was wondering if i could retrofit this to my V50?

http://www.youtube.com/watch?v=ql1jhaFl9-Q&fea...

[rustyveedub]

I have now worked out that i have Premium audio as it tells me me when i turn it on (how did i miss that)!