I've built my entire car stereo for free. Including my subwoofers that i made from scrap wood, gorilla glue and some KLH sub speakers i got off craigslist for free. I found a couple of really nice Kenwood speakers at a junk yard. the kind that has a lower frequency cone with a small tweeter in the middle. They crackle a little bit but not to bad. the rubber is in perfect condition and there isn't a mark on ether cone. could there be some dirt that's causing the crackle or something else? I've spent a lot of time making this system without spending any money and I'd like to keep in that way.

mcclankadangin, October 2009

If this is a serious question...

Diagnosis...

It's rare for a speaker to "crackle" usually a speaker either works or it doesn't work - it's difficult for a speaker to crackle on its own - the speakers are probably being asked to crackle due to a crackly signal being sent to them. And you suggest that you have more than one crackling speaker.

Take a speaker out of the system it's in - remove it - and test it on a household sound system or in another vehicle (ignore impedance) - seee if it crackles there. If it still crackles when you move it then look for replacement speakers.

If the speaker does not crackle after you move it you then know that the crackling is not speaker related. It will probably be - interference from the car's electronics due to poor grounding / screening of the interconnecting cables or dirty control pots - you can buy cleaning spray or perhaps in your case ask a friend to give you a squirt or two for free.

See here for impedance in Loudspeaker Amplifiers (free)
http://en.wikipedia.org/wiki/Impedance_matching

Good luck...

Peccavi, October 2009