SparkFun admp401 microphone OPA344 distortion

Other Miscellaneous
1

Dir Sirs

I am electronic engineer and about a year (or two) ago I bought Sparkfun circuit board of Analog Devices ADMP401 microphone with OPA344 amplifier circuit board. i belive the circuit is ADMP401-breakout-v13

I am using it for a new prototype.

In my project i have to insert the microphone card into a trumpet bell, in order to send the sound coming from the trumpet and transfer it to wireless transmitter.

The transmitter send the waves to wireless earphone.

The circuit works fine with clear pure sound when the source is talking around or TV sound in the background.

However there is a problem when i am playing the trumpet the sound in the earphones becomes heavily distorted no matter what position of the microphone and even lowering the volume of the earphones.

I assume that its one of the two,or the microphone is over saturated or the OPA344 gain is to high.

I will be happy if you can advise and help me with this problem.

Thanks in advanced

Nevat ben haim

Recomp computers

2

Hello Nevat, and thanks for posting on the forums. :slight_smile:

It sounds like you’re over saturiating the microphone with sound and that would cause distortion. It’s a bit like yelling into someones ear. They will hear something, but it’s going to be distorted.

Try wrapping the microphone in cloth like an old sock to see if that helps with the distortion.

3

Hello Chris

Thanks for the information,

It is clear that this is saturation cause the output sound is chopped.

My question was if the reason is defenetly the microphone , or it is the OPA344 over gain .

I know one engineer that said microphone cannot be saturated from this distance (Sound Level Air Pressure)

Nevat