MIC volume is very low

I am using an electret microphone WM 55A103(Philips make) in my vehicle tracking unit. I have connected this at both the MIC1(With bias current of around 1.2mA) and MIC2( Without bias) but, i am getting very low voice output.

Can you please suggest me to get good audible sound from wavecom Q24 series module.

I tried even with controller 2, by setting AT+VGR=0 & AT+VGT=1 to 102, i am getting noise at the higher value. But in the range of 30 to 60 i am getting little bit good voice but that is still less for me, since my application is for around 1meter distance.

Please suggest me…

Thanks & regards,
EI Labs India Private limited.