Hi, I am novice when it comes I.C.E so I may be completely wrong.

I am looking to change the speakers in my GP. I will be sticking with the standard H.U for the time being but I want to know is there anything I need too look out for when choosing speakers. I know about the size of the speaker but is it possible to buy speakers that are too powerful for the H.U

I have been looking at these speakers
http://www.ebay.co.uk/itm/New-Pair-...3?pt=UK_In_Car_Technology&hash=item19def77ca5

Thanks