I'm having mic problem after having my K610im hardware running K610i firmware.
People on the other side of the call cannot hear me clearly, as they describe the volume of me speaking is like me stand far away from the phone.

Can anyone help?

I have try K790_acoustic_by_sunfire7_for_k61X, but the mic is still not sensitive.
I tried to call my home phone too, and it is really soft.

What can I do? Is there any Acoustic pack which have Mic Volume Modded?

Million thanks in advance..

maybe, some dust particles entered there, at the mic. you need to clean it, i'm sure, or bring it to service center, if it's still under warranty

sadly to say, my k610i which i just flash with w660i mic seemto got the same problem. any idea why?
any solution?

there is problem with your mic.100% sure.hardware problem.
try to flash back to k610 firmware,if you are blaming crossflash making the mess.
i have done many pieces of k610@w660 without any problem in mic.

BR

try changing the acoustics...if not...do as hasmidzul_jojo said....reflash back...