Shaker 500 has the 2 front amps for the front door subs. Shaker 1000 has the 2 front amps for the front door subs and 2 amps for the 2 rear subs.

 

Ok guys, finally found it.

Since there are no official dealers in Europe of Ford US. I had to find the special dealers. The one that I found in Belgium is one that is doing the service of the military vehicles of the US army base in Belgium.
I went overthere and we have swapped the radio with one from the GT500 (the only one in Belgium). My front speakers worked as new.

Then the problems started:
When I asked the guy to replace it (since its still under warranty) he told me that this was no possible (only possible for US army people). There is no way I can get a Shaker from them as they don't get the go from a Ford dealer in US.

My questions are now:
- Can somebody provide me a dealer that can tell this dealer in belgium that he can replace it?
- If nobody can do the question above. Can somebody tell me where I can find a cheap shaker1000?

Greetings