Sunday I pulled my clip zip out of my car to go on a bike ride and noticed a problem. When using head phones I can’t head any vocals, and the rest of the audio is really hollow. It sounds almost like I’m standing outside of the bar the band is playing at, it is all bass and treble. I plugged the clip zip back into my car and it sounded perfect through the factory stereo.
I have tried with both my JVC and the sansa earbuds, and my sony head phones. I have played with the eq settings and can’t find a setup that sounds decent. Is there a powered speaker setting that I have to flip between? This is making my work day pretty boring and I need to figure this out.
Make sure the plug is inserted all the way into the jack. Twisting while pushing helps.
What you are hearing is caused by two things. First, what you are most likely hearing is the differential signal between the left and right signals. A stereo headphone connection employs three wires, a left signal, a right signal, and a common ground connection.
If the ground connection is lifted, you will hear the differential signal between left and right. Now here’s the weird part. A singer’s voice is very often a monaural signal, recorded from one microphone, blended during recording to both channels. If you have a connection problem, the voice will “drop out”, since it exists equally on both channels.
If you have a studio recording with a live singer, the other microphones in the studio will pick some of the voice. It’s this “voice” that you will hear when the ground connection is lost.
I have seen this happen numerous times if the headphone plug is not fully inserted, if the headphone cable has a damaged wire, or if the headphone jack in the player is damaged.
To troubleshoot, try another headset. Be sure that it isn’t a 4-ring headset (as used for mobile phones, with a built in microphone). With the existing (suspected) headset, you can try manipulating the cable at the plug to see if there’s a damaged wire.
Bob 
