Dear Valued Customer,
I'm truly sorry to hear that the sound terrible, this must be frustrating. Have you tried to adjust the volume? Have you performed any recent OS update? For further troubleshooting, feel free to reach out to me at customerloyalty@asus.com and provide this link for reference. I'll do my best to provide a quick resolution to your case. Your feedback is important as it helps with improvements to ASUS Support channels.
Thank you for choosing ASUS!
Best Regards,
Jamalie,
ASUS Customer Loyalty US Support