I discovered that my takstar pro 80 has a serious channel imbalance at around 4khz when i listen to a sine wave sweep.
I actually use SineGen but this link will do. you'll notice it at around 10 to 12 sec of the clip. But i have a feeling its because my unit is defective.
At 4khz, the sound is almost absent at the left driver. The sound pans extremely to the right. I wonder what effect it has on actual music listening.