I'm using a RunCam HD2 and my sound is junk.  It picks up a lot of wind noise and other garbled messes.  I watch a lot of other videos where it a nice motor sound most the time.  

Is there audio settings or is it just what you get from the runcam and others are using GoPro or something better?

You know, judging by the sound of some of the pro guys' videos I think maybe they're muffling the camera. You loose a lot of the top end which is why it sounds more growly... I've been thinking about trying it on mine just to see

I dont have the RC HD2, but I do have the RC3.  How does it compare to ?

RC3 may be a little better but it still has that garbled loud static sound. I've read that it's not wind noise its just the mic struggles with that high of volume and clips.

There is an episode of RCModelReviews, on YT, where it is proven that simply placing a bit of foam on you mic will greatly improve the recorded sound quality. I personally cannot vouch for this but Bruce is a thrustworthy guy I would think.

Edit: here it is:

(01-Jun-2017, 05:29 AM)rryyyaann Wrote: ...  I've read that it's not wind noise its just the mic struggles with that high of volume and clips...

The thing about clipping is that it causes distortion not noise. I can confirm that an unaltered action cam is likely to have clipping when sitting between 4 noisy props but the wind noise is like clipping plus noise. 

Because both are likely happening you probably want to troubleshoot each issue independently. Wind noise could be resolved or reduced via the Bruce method that Thibault shared. Clipping would require reducing the input audio before the cause of the clipping (I don't know if the clipping happens in analog at the mic, or in digital during processing/encoding of the file).

To tune your ear to hear each issue it helps to understand both. One way to get a feel for which is which of course is to record some HD video on a windy day. Do a punchout way up into the sky then dive back down camera first toward the ground (recover before crashing of course :p) You'll be able to hear the growl of the props. They have pitch and sound like a distorted high pitch growl. That's your actual audio clipping. 

Then as you fall... all the static noise is what's left from wind noise. 

Some more info for anyone who is curious about clipping vs noise:

Here is an example of clipping


The gray portion of the wave is deleted because it's amplitude was greater than the maximum recordable

As you can see even on clipped audio you maintain pitch to a certain extent. As multiple pitches modulate eachother you might loose some of the sounds but ultimately you're going to get some sort of tones even out of very clipped audio... 

To think of clipping mathematically consider that each digital point on a wave gives instructions to the computer on how much or little pressure should be applied to the driver (speaker). So for example the crest of a triangle wave in an example audio file with amplitude range from -10 to +10... If the crest values were 0,3,6,9,12,15,12,9,6,3,0... once clipped the values would be 0,3,6,9,10,10,10,9,6,3,0 (notice the 10s in the middle). What this does it turns the triangle wave into more of a trapezoid wave lol... This distortion usually sounds like a buzzing sound. 

With wind noise because the pitch is random it covers up other noises. When there is wind noise plus clipping then you pretty much cover up the existing audio all together. It would be like typing several layers of random letters over existing letters ultimately you wouldn't be able to tell which letters really say the words on the page. (I could go into noise floor and why you can hear both but the non-noise audio sounds quieter behind the noise but I'll leave that out in this case but it might be worth more research)

Example of noise:


To imagine the noise being clipped just imagine removing the information from the wave from the top 40% of the image and the bottom 40% leaving just the middle 20%... you'd still have random pitch but the peaks above and below -10%/+10% would all be cut flat (or near flat depending on what source caused the clipping. This is an area where digital vs analog plays a big role. And it's why many say you can't exactly recreate the sound of a tube amp)

anyway... I probably overshared but hopefully it helps with troubleshooting audio engineering issues

Nicely explained.

To lower the volume in order to prevent clipping is very difficult. I seen some mods for the xiaomi yi, and the best solution always was to replace the original mic with a less sensitive one.

It probably also has to do with the surrounding mount of the camera. If the 3D printed TPU mount is covering a mic hole it would change the way it sounds as well, right?

The Gopro session 5 sound is superior to the runcam 2 in terms of wind noise

(02-Jun-2017, 05:25 PM)PaulMek Wrote: It probably also has to do with the surrounding mount of the camera. If the 3D printed TPU mount is covering a mic hole it would change the way it sounds as well, right?

Absolutely. It would muffle the sound.

This might not be a bad thing though. I'm going to be experimenting with muffling sound tomorrow. I may post a video on it if I remember.

Did you do some experimenting on this Carl..? I'm interested to find out how it went.

Hey Tom,

I did... no luck at all.. in fact it sounded just as bad as before it was muffled...

However I did fix the issue! Here are the steps I took:

1. I went to my local flying field and did some flying with the Runcam
   
2. I pulled up the footage on a computer to review the quality
   
3. Then I drove to Best Buy
   
4. I asked the guy to open the cabinet with the Hero Session 5 in it
   
5. I purchased one for too much money
   
6. I flew with the new camera
   
7. Viewed footage
   
8. No more wind noise!
   

lol.....

Unfortunately... I just couldn't get the RC2 to do what I wanted with sound, and it was a top 3 reason for going with the gopro session 5 specifically (rather than just the session). Now that I've flown with it, I can see exactly what the pro guys are doing... They really are using a better camera. :\ That's about it. From there you can apply some post-production on the audio, a bit of filters and maybe some compression to control volume and it sounds better.

If you are willing to experiment, I was also looking into this topic - on my yi I have used a mic pulled from my old xbox 360 headset and it sounded way better. The mic had an extra component soldered between the legs that appeared to be a small SMD resistor. I don't know if the quality was improved because the mic was of higher quality or did the resistor do the job, I don't know enough about how audio is processed in those circuits... anyway, my experiment was ruined because the audio on this Yi stopped recording completely (I don't blame the mod for the fail as the camera was randomly failing to record audio at this point - it was abused for over a year)

I have to make a jig to really test it now on another camera...

But... I was also looking at how the mics on GoPro are soldered on and they all have extra capacitors between the legs and some other pads. Maybe someone will get any useful info out of my mumbling here and figure out any kind of hardware mod for the existing mics

Below are some samples I stitched now. Please ignore my flying as those are just some old random clips I found. First part is stock, so it is LOUD:

Here is a video on how to fix the audio issue of the Runcam. I use a Firefly Q6 and haven't had any bad audio. Much more cheaper than a GoPro.

Use these to cover the mic, you can modify the foam to suit your needs.