Hi,
I'm working with the SmartSound one development board. I see about a 4.5dB difference betweeen left and right channel. This was with the T5837 eval as well with my own prototype. Any idea how I can solve this? I'm looking to determine the exact SPL with the microphones and I used a calibratedsource to know the input.
Hi,
I have a few questions regarding the issue that you are experiencing. Could you please provide some additional information?
I assume that the 4.5 dB difference is a measured difference between the sensitivity of the microphones. Does this difference change as you adjust the level and/or frequency of the test signal?
One possible cause that comes to mind would be if any particles were allowed to enter the microphone port. If you have not already done so, please take a look at AN-100 MEMS Microphone Handling and Assembly Guide
Regards,
Mike
Hi Mike,
Thank you very much for your input. I've since build more PCBs with the microphone and they don't seem to have the difference. It was with a glidesweep, so over the whole frequency range. It must be a handling issue. I have microphones on both sides of my PCB and use a small oven to produce the boards. I did tape over the holes in the PCB because I need to put it in the oven twice and I was afraid the hot air would damage the mics but expanding air is also a possible issue. I'll test some more with producabillity like this, but if you have any tips I'd love to hear them. This is prototyping phase, in production I don't believe this will be an issue.