Default mic issue during call [Solved]

i really need some help regarding this issue got a used nexus 4 from ebay and im facing facing the low mic issue during call friends on the other end yelling at me so i experimented some methods the thing is whwn i put mouth right infront of the mic it is all good but when i hold my phone as normal the issue starts mic is working well in all other apps so it should be a software issue some one please help me yje problem stays on all custom roms !!
█ Galaxy s3