Finally got the courage to open up my S9 as the microphone broke down. It's working perfectly now and I paid only $15 for the replacement parts! (sorry for the low quality
Samsung Galaxy S9 G960F original microphone
Kithouse S9 UHF Rechargeable Wireless Microphone System Karaoke Microphone Wireless Mic Cordless Dual with Bluetooth Receiver Box + Volume Control ECHO for Karaoke Singing Speech Meeting Church, 200FT - Walmart.com