I have a Lanzar 1200watt amp.
I am only running it at the 400watt level (4ohms) (for now).

When listening to the radio and the amp is switched off everything is fine, but once the amp is switched on the speakers go fuzzy. This only happens with the radio, when a cd is playing everything is fine.

What is the reasoning? any way to fix it?

 

do something for me, turn on your amp and radio w/ volume all the way down. is the fuzz still there? do the same with a cd now too. same thing, still there?

 

I was going to say its a ground but if it doesnt do that with a cd then not to sure. Your sure its just not bad reception you dont hear till the amp is on? Do what the above post suggested. If its still on when the volumes turned down you can rule out reception and It wouldnt hurt to check your ground connections after that.

 

Thats the beauty of Class D....they CAN cause AM/FM radio interference. Their switching freq. is in the same range of radio bands, so it can cause noise. There is nothing wrong with anything, its just they way it works. Thats why it only shows up when you are listening to the radio and not the CD...

The way to fix it would be to have the amp as far away from the antennea and/or radio, if its still there, then you either live with it, or try another amp. the lanzar's aren't that hot, they are very cheaply made. While they will put out the rated power, they are notorious for causing probs. Try a JBL, or something even more pricier and it MAY fix it. The only way to truely 'fix' it is to go with class a/b amp (ie current hogs, lol).

Sorry to break the news to you, but thats the 'drawback' of class d's (along with having limited freq response, but a tri-path chip fixes that).

Here is a thread that explains some about it.
http://www.carsound.com/cgi-bin/ubbc...c;f=2;t=001762