Have you first switched the speakers (easiest to switch cables at the amplifier)?? If it then comes out the left, it is not the speakers.
If it is the speaker, can you get your ear close enough to the speakers, so you can determine which driver.
A major problem is when the driver is drunk. Severe visual impairment is also potentially lethal. We are not allowed to use the sex of the driver as a determinant. Very short drivers also pose a threat: the eyes should at least clear the steering wheel. Those who have a suspended licence may or may not have a problem depending on whether they drive or not, or, more precisely, whether they are caught in the act or not.
Change your speaker connections as previously mentioned so that you can at least see if the problem is with the speaker itself. Replay the offending musical passage to make sure what it is you are hearing. Press your ear as close as you can to the drivers. Don't be surprised if the tweeter turns out to be the hardest to hear properly. You may try applying slight pressure with your fingers at the edge of the driver to see if it makes it act up. If all else fails, try to get the dealer to send someone to your home to ascertain that a problem actually exists. Then you may yet have to send the speakers in for repairs. Good luck.