Hi Forum,
What’s the best solution to keep, electromagnetic interferences as low as possible using Teensy/ Audio Adaptor Board and recording audio over a microphone via cable?
Best solution of course without any cable:
Soldering the Electret Condenser Microphone directly to the Audio Adaptor Board, as shown in the tutorials. https://www.pjrc.com/store/microphone.html
Unfortunately regarding space concerns I need a wired microphone.
https://www.dropbox.com/s/6brdutu55yoovfu/01_WiredMic.jpg?dl=0
Test:
I have connected the Electret Mic. to micin via a microphone-cable (1 wired cable with shield 1.5m length).
Test without any electromagnetic noise source:
Vpp max = 0.07V.
https://www.dropbox.com/s/pewegxxygx9kp1o/02_Vpp_Silence.jpg?dl=0
Test with 100Watt halogen spot and dimmer near microphone, mic-cable and Teensy:
Vpp max = 1.04
https://www.dropbox.com/s/m5td1tmiuq49wna/03_Vpp_Silence_Halogen.jpg?dl=0
Test with 100Watt halogen spot and a dimmer near microphone, mic-cable and Teensy holding the mic. in my hand:
Vpp max = 2 (saturation)
https://www.dropbox.com/s/iuamf674ojnnjta/04_Vpp_Silence_Halogen.jpg?dl=0
As you can see the electromagnetic influence during my tests was huge. The mic went even in saturation. The noise frequency was always 50Hz which is supply frequency in EU. I think the noise introduction was inductive.
My questions:
1.) Does the test reflect the reality or partly the reality, if I want that my project works also on stages, with huge halogen spots, instrument-amplifier and a lot of other stuff?
If yes what can I do to improve the solution?
1.) Convert the analog signal to digital signal via shortest connection and communicate digitally with Teensy.
For example using ADC via I2C like: https://www.adafruit.com/product/1085
But in this case I don’t know how to handle it with Teensy Audio System Design Tool https://www.pjrc.com/teensy/gui/index.html?info=AudioInputI2S ?
Because I need to adapt the signal at code side… adding some filters, amps, frequency and amplitude detection etc..
Or can you recommend me an ADC breakoutboard which I can easily implement with Audio System Design?
2.) Using a XLR microphone and cable, but I don´t understand if hooking up to Teensy/ Audio Adapter Shield is possible. XLR has 3 connections. Teensy only 2.
I`m very grateful, for any advise.
Best regards
What’s the best solution to keep, electromagnetic interferences as low as possible using Teensy/ Audio Adaptor Board and recording audio over a microphone via cable?
Best solution of course without any cable:
Soldering the Electret Condenser Microphone directly to the Audio Adaptor Board, as shown in the tutorials. https://www.pjrc.com/store/microphone.html
Unfortunately regarding space concerns I need a wired microphone.
https://www.dropbox.com/s/6brdutu55yoovfu/01_WiredMic.jpg?dl=0
Test:
I have connected the Electret Mic. to micin via a microphone-cable (1 wired cable with shield 1.5m length).
Test without any electromagnetic noise source:
Vpp max = 0.07V.
https://www.dropbox.com/s/pewegxxygx9kp1o/02_Vpp_Silence.jpg?dl=0
Test with 100Watt halogen spot and dimmer near microphone, mic-cable and Teensy:
Vpp max = 1.04
https://www.dropbox.com/s/m5td1tmiuq49wna/03_Vpp_Silence_Halogen.jpg?dl=0
Test with 100Watt halogen spot and a dimmer near microphone, mic-cable and Teensy holding the mic. in my hand:
Vpp max = 2 (saturation)
https://www.dropbox.com/s/iuamf674ojnnjta/04_Vpp_Silence_Halogen.jpg?dl=0
As you can see the electromagnetic influence during my tests was huge. The mic went even in saturation. The noise frequency was always 50Hz which is supply frequency in EU. I think the noise introduction was inductive.
My questions:
1.) Does the test reflect the reality or partly the reality, if I want that my project works also on stages, with huge halogen spots, instrument-amplifier and a lot of other stuff?
If yes what can I do to improve the solution?
1.) Convert the analog signal to digital signal via shortest connection and communicate digitally with Teensy.
For example using ADC via I2C like: https://www.adafruit.com/product/1085
But in this case I don’t know how to handle it with Teensy Audio System Design Tool https://www.pjrc.com/teensy/gui/index.html?info=AudioInputI2S ?
Because I need to adapt the signal at code side… adding some filters, amps, frequency and amplitude detection etc..
Or can you recommend me an ADC breakoutboard which I can easily implement with Audio System Design?
2.) Using a XLR microphone and cable, but I don´t understand if hooking up to Teensy/ Audio Adapter Shield is possible. XLR has 3 connections. Teensy only 2.
I`m very grateful, for any advise.
Best regards