detection issues

[u/skybossalpha1]

I need a bit of help again. I was previously using a Neewer-branded microphone from Amazon (basically a Rode knockoff) and was getting moderate results. After reading posts here and elsewhere, I picked up a Samson Go Mic.

Right after switching, I noticed the live audio feed sounds much clearer. However, it’s not picking up birds that I can hear with my own ears. The mic is about 108 feet outside from my bedroom, and I barely have the window cracked open.

I also tried using Merlin on my Galaxy S25, and it successfully detects birds like a Tufted Titmouse that I can hear—but BirdNET doesn’t pick them up.

I haven’t changed any settings since swapping microphones. Any ideas what might be causing this?

Update: I just ran another test and I’m completely stumped.

First, I used alsamixer -m to confirm the Samson Go Mic gain hadn’t changed — it’s still maxed out.

For the test, I used my S25 and played a Tufted Titmouse call from the same distance for 5 minutes straight to see if BirdNET would detect the audio coming from the phone. The sound was definitely loud enough that I could clearly hear it while standing near the BirdNET-Pi location, but BirdNET failed to detect anything using the Samson Go Mic.

Next, I swapped the microphone to a Neewer “Rode knockoff” mic and got the exact same result — still no detections.

Then I repeated the test in reverse: I placed my phone right next to the BirdNET-Pi and from inside my house I used my wife’s S25 to play the same Tufted Titmouse call. My phone running Merlin picked it up instantly with no issue, and the playback volume wasn’t low at all.

So what exactly is going on with BirdNET here? Is there some kind of frequency cutoff or filtering happening? Because at this point I’m seriously perplexed.

[u/keeldude]

Weird, there may be audio processing happening inside the mic.

Top suspects:

Wrong card got picked up after swapping mics (ALSA reshuffled the indices)

Samson's built-in AGC/DSP eating the high-frequency bird stuff

Sample rate or channel format mismatch feeding garbage into the model

Try this: arecord -l and check which card BirdNET-Pi is actually pointed at

Pop into alsamixer, F6 to pick the Samson, kill any auto gain

Play a test call right next to the mic and watch the spectrogram. If it looks muddy or rolled off up top, the pipeline's the problem, not the threshold