[admin]

The CDG spec is stereo audio, just like Audio CDs.

What a particular manufacturer chooses to place on the left and right tracks is their decision. Anything goes. To have music and voice on left (for example) and music only on right is one way some manufacturers use. Then, muting the left track and playing the right bridged to both channels would only play music.

I expect the problem you are hearing might be the control settings on the Karaoke player at the bar. I expect a "Vocal Eliminate" button might play only one track and duplicate it to play on both tracks (called bridged output). The next time you are at that bar, check with the operator to see what controls are there that might affect which channels play.

Another point we wondered about is if the bar's player is mono (one speaker) or stereo (two speakers)? If it is mono, playing a true stereo tracked song would sum the channels (with some control settings) and thus make the sound louder.