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How to replace mini microphone with more sensitive mic? Answered

Hi

I am trying to replace mini microphone (is very similar to mobile phone microphone) of Audio bug with more sensitive Standard electret microphone with intention that it pickup sound from more than 1 metre distance, and in doing so I am getting too much noise in Audio bug out-put.

Do I need pre-amp? Is there any better way to do it? If pre-amp then how to harmonise out put of pre-amp to the input of audio bug?

Any help.....

Thank you.

3 Replies

user
Goodhart (author)2011-07-17

First off, you will need to make sure that the mic is "matched (impedance)" to the device you are putting it in. This is especially true if you add a preAmp.

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user
ksaus (author)Goodhart2011-07-17

I am mesuring impedance(ohms), voltage, amp at preamp output end and input start of mobile microphone and publish here soon to get your help for how to match them...

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user
ksaus (author)2011-07-20

Hi Goodhart, Thank you for your reply. In order to match impedance of output device(pre-amp) with input device (mobile phone mic input)

I have mesured current which is as follows.

Pre-amp out put is .0502 volts and 0.100 amp
Mobile mic input is 1.820 volts and 0.690 amp

In order to match impedance, I have attached 0.1 uF 25V green capicitor between positive of mobile input and one main output of pre-amp. Noice has reduce little bit but not completely ....

Can you please help further?

Regards

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