Also got this topic in the ice section but not getting any luck in there so hopefully someone will have the answere in here.

Ive replaced the standard HU with a new Alpine Hu,in MY05 Impreza but the radio reception is dreadfull both on fm and mw.
I have already checked the following
Blue power anntena cable
Earth Cable
both seem ok Ive even tried running an extra earth cable from the Hu
Suppliers of the Hu say its the rubbish anntena in a Subaru thats the problem.

Anybody had this problem and how did you fix it.

 

try wrapping the ariel connection on the headunit in electrical tape,my reception on my cda-9855 was shocking,but after wrapping in tape the reception is crystal clear,i think it is getting interferance from another source

 

Will try that hopefully it will work its beging to drive me