Any tips on how to improve audio quality on the internal microphone of T54IR-ZE-S3?

[alekk]

I recently picked up a couple of T54IR-ZE-S3 eyeball cameras that I've been pretty happy with.

Nice bonus is that it has an internal microphone ... which is certainly easier than running a powered pigtail and audio plug to an external microphone that one has to "hang" somewhere.

The audio is decent for conversation close by, but when monitoring the street, it's difficult to pick up conversation from the sidewalk 50 feet away ... and yes, I have the microphone volume slider maxed out at 100%.

While enabling the Noise Filter removes the background rumble, it makes the conversation even more muddied as it clips those tones.

Based on a couple of tests, the sound is a bit cleaner if I turn the camera's Noise Filter OFF and then run it through Audacity using the Noise Filter. Which isn't too surprising since it can analyze the entire waveform (and I can tune the parameters) whereas the camera has to do real-time filtering.

I did a little testing with Audio Encoding's (G.711A is default - there's also PCM and a few others) and the Sampling Rate (default is 8000 - some will go as high as 64000) but it's hard to have a repeatable test to assess differences. So this wasn't a thorough test - does anyone have a "best" recommendation here?

In fairness, the microphone is not a shotgun microphone ... so I think I'm just hitting the limitations of the design.

But curious if anyone else has any suggestions on how to improve the audio - thanks in advance.

 

[wittaj]

As you pointed out, these are not high-end microphones. Some of the cameras do better than others.

I have found the bullets tend to have better range than the turrets.

My Z4E has an incredible range. I could hear and understand a couple in a Christmas argument 6 houses away LOL. Granted their voices were raised, but still.

But 50 feet for an internal mic is probably pushing it. I forget if that model has the ability to add an external mic, but if so that would be the way to go.

 

[alekk]

Thanks for the feedback @wittaj .. any idea why the microphone is better on the bullets?
BTW, since the Z4E is a "telephoto" camera, nice work by Dahua with whatever they did so the microphone similarly "reaches" out.

FYI that on the T54IR-ZE-S3, it's a small "slot" on the bottom of the eyeball just behind the lens. The micro-SD slot is on "top" (actually says "UP" by it) which I presume is to minimize the chance of water getting in the microphone.

Short of opening up the eyeball and hacking into it, I do not believe there is any ability to add an external microphone as the pigtail only has a Ethernet and 12V in.

I'm not expecting "Hollywood sound quality" ... and it's REALLY nice having the built-in internal microphone - just wondering if there is anything else I can do to improve it.

 

[wittaj]

I am guessing that the bullets simply have more room for maybe a bigger/better mic or ability to have a bigger opening to allow more sound to get in.

Yeah I couldn't remember if the new ZE-S3 had a mic wire or not.

 

[duplo]

for me, AAC 64000 without noise filter, mic around 90-95 sounds the best.

 

[alekk]

Thanks @duplo as that seems to work a little better - I'll try doing some more testing.

BTW, I like the Noise Filter idea ... but it's either ON/OFF and (IMHO) overly aggressive.
So maybe in a future release, they will provide a slider to adjust the amount applied.