Speakers have gone really quiet?

What causes crackling in car speakers?

• I have a crappy old VW Golf that I put a JVC head unit into. It was previously and recently in a BMW I had, and sounded great in that car, so I know that the head unit is good. I can only play my iPod through it right now, as the VW's antenna mast is gone. All four of the main speakers are replacements, with the back ones being brand new. The radio sounds like it's being played in a drum. There is almost no mid-range, and some vocals are really difficult to hear. I have to keep the bass and treble settings on the radio down to almost nothing, and I have completely shut off all the EQ settings in my iPod. That helps a little, along with keeping the volume way down. Even with all that, I still get crackling in the speakers, and it generally sounds like crap. The car had a different JVC unit in it when I got it, and that unit sounded like crap too. I put it in my BMW, and it sounded dynamite! The VW has a JVC connector plug wired into the dash. The speakers seem to be direct wired from what I can tell instead of going through the dash harness. I assume it's a wiring problem of some sort. Any suggestions?

• Answer:

  PROBABLY NOT A WIRING PROBLEM: Most likely the crackling noise is coming from the volume control potentiometer (potentiometers are variable resistors). It is most likely dirty. It "might" be possible to clean the potentiometer with electronic contact cleaner spray (which you can get from an electronics store). Unlike WD-40, the contact cleaner should not leave a residue. If the potentiometer can't be cleaned, it might be able to be replaced. The potentiometer "might" have an on/off switch attached to it, and it might be hard to replace them (because the replacement might not be the same size or shape and might not fit in the space. You might try contacting the company that makes the JVC to see if they have replacement parts. WIRING PROBLEM? The speaker wires (where they connect to other wires or plugs) could be loose, corroded, or dirty. But, it is far more likely that the crackling is caused by a dirty potentiometer. SPEAKER PROBLEM? It is also possible that the crackling is coming from the speakers, themselves. But, if the crackling is coming from all 4 speakers, it is likely not caused by any one speaker. DIRTY HEAD? Though you claim that the head is not the problem, it "might" be possible that the head is dirty. NO MID RANGE: You should be able to put in an equalizer to adjust the mid-range (though it will cost you). Likely the mid-range problem is not associated with the crackling problem.