Why can't I hear Jimmy Page?

September 26, 2006 2:04 PM

I'm having issues playing back music. It all has to do with the left or right channel being washed out: Sometimes the lead vocals or lead guitar from a radio signal isn't heard, sometimes its the same for listening through an ipod with headphones and through a computer with headphones. There is a bit >

I'm more concerned with the digital files I have on my pc and those that I've transferred to my ipod. Some of the recordings are albums that I've ripped with EAC some are downloads. I'm not sure how to tackle this; any help would be appreciated.

posted by premortem to media & arts (7 comments total)

Are you using the same headphones for both the iPod and the computer? it sounds kind of like a bad headphone cable to me. Though "washed out" is not a term that makes much sense for me for audio.
posted by aubilenon at 2:09 PM on September 26, 2006

not sure the correct verbage, but by washed out, I mean that lead vocals or lead guitar can't be or can barely be heard. And I'm using two different sets of headphones, one of which is brand new.
posted by premortem at 2:27 PM on September 26, 2006

Though "washed out" is not a term that makes much sense for me for audio.

Yes -- by washed out, do you mean silent? Or distorted somehow? On your computer, what happens when you adjust the pan/balance control (on a mac, System Preferences -> Sound -> Output)? If the washed-outness moves with the panning (i.e. you pan towards the good channel and the washed-outness moves into that channel), it is probably the files, if not, it is probably hardware (headphones, cables, or headphone jack perhaps).
posted by advil at 2:28 PM on September 26, 2006

On all the tracks that have the problem, the right channel is too faint and inaudible. So we're saying that its a file issue. How would I encode these to avoid this problem?

Is there anything I can do to the files that I have that would fix this?
posted by premortem at 2:42 PM on September 26, 2006

This doesn't make sense in light of the fact that you also have this problem with your ipod, but could it be that there is a fault in your computer audio setup? I have plugged my headphones into the port on my work speakers only to find out that it was killing the right channel of my audio. I've also had the onboard sound in the Dell at work give mediocre performance on one channel.
posted by mikeh at 2:44 PM on September 26, 2006

This problem is caused by the phase one of the left or right channels being inverted. Vocals, which tend to occupy the "centre" of the stereo image, and thus are the same in both the left and right channel - will therefore be cancelled, or nearly cancelled out.

This problem is commonly caused by a faulty audio jack plug. Check your cables and plugs.
posted by Mwongozi at 3:23 PM on September 26, 2006

Mwongozi's point is normally associated with stereo speakers, not headphones.

For one, since the left and right channels on most (all?) headphones share a common ground, it is somewhat harder to wire them out of phase (you could reverse the phase at the transducer end, but at the connector end you can only channel swap or connect the transducer across the two channels - more on this later).

Also, the effect of reversed phase would not be as dramatic with headphones (for certain definitions of dramatic effect). The out of phase problem is mostly due to the fact that each speaker is exciting the same block of air, and exciting the same block of air in opposite ways cancels out. However, the block of air excited by each headphone transducer is completely isolated from the other. Think about a tug of war, if both teams are pulling equally on the same rope the flag doesn't move, but what if they are pulling different ropes..

Phase is important in other ways, of course. The delay between a sound arriving at one ear and then the other gives spatial cues about the sound's source.

I tried listening to an inverted phase track on headphones, and the sound is clearly different, but I wouldn't really call it washed out, and the effect didn't seem similar to out of phase speakers to me. I might be doing something wrong though.

Of the possible ways to mis-wire headphones, one is to wire a transducer from the left-channel to the right-channel (not to ground at all). This would have a dramatic effect on the sound produced, and it would include virtual muting of sounds common to both channels (like lead guitar and vocals), but basically no effect for sounds on only one channel.


So anyway, I don't have any idea what's going on, so debug, debug, debug.. If you can produce the same effect when the only common elements between two setups is the file and electricity from the wall, you know it must be the file that has a problem..
posted by Chuckles at 8:19 AM on October 13, 2006