Hi.

Here's my first preliminary test of what I call a 'Nano Mic'. It's basically the smallest microphone that I can build that has a good ECM capsule in it. The capsule used is the Primo EM172 omni-directional ECM.

This is my very first test of the microphone with the Pocket and I think it sounds really good. It's an external mic that's small enough to add to a Pocket without adding too much bulk and is also an alternative to the internal mics of the Pocket.

With this microphone being omni-directional it allows for recordings that have some sense of the atmosphere of the recording location while being able to pick up dialogue very well. Even at full arm's length it does a very good job of picking up the user's voice.

I dare say that this is the most compact Osmo Pocket setup with an external microphone that's highly likely to increase the Pocket's ability to be used as a vlogging camera. Maybe it's the best Osmo Pocket vlogging setup?

I'll be doing a 'how to' guide at some point with further examples. For anyone with basic soldering experience this microphone is very easy to put together and can be built for less than £20.

I'll also be putting together another similar microphone that's right angled with a cardioid ECM for directional dialogue use.

The ECM capsules that I use are the Primo range supplied by MicBooster https://www.micbooster.com These are the same capsules that are used in the excellent MicBooster Clippy range of lavalier microphones.

Cheers,
Dave.



Here's a link to my Osmo Pocket YouTube playlist:


Here's a link to a playlist that has video examples of the Osmo Pocket, if you check the descriptions for these clips there's links to where you can download them:

Well done again Dave.

"Right angled connector, cardioid pattern" where have I heard that before.   Great minds do think alike.

Bob

BobWinNV Posted at 3-24 19:43
Well done again Dave.

"Right angled connector, cardioid pattern" where have I heard that before.   Great minds do think alike.

Thanks Bob.

I'll see if I can dig out some examples of the cardioid, I use it for other small cameras and it really does help to keep the setups small, just as this mic does.

I appreciate that some people use rig systems to add extra functionality to their Pocket's. But my interest is to use it as lightweight as possible, this is where these tiny mics really come into their own.

Cheers,
Dave.

David_Harry Posted at 3-24 19:55
Thanks Bob.

I'll see if I can dig out some examples of the cardioid, I use it for other small cameras and it really does help to keep the setups small, just as this mic does.

Thanks Dave.

I will be interested in building at least one cardioid from the parts that I have just ordered.

I am wanting to keep my Osmo Pocket in the pocket as well.  

At home it sits in the small table tripod that you saw in the picture with a female to male lightening cable to my iPhone/iPad.  It is a nice setup for testing as I can go from recording to checking on the phone/ipad  to airdropping  to the macBook Pro for analysis in a moments notice.

Bob

Dave, well done, loud and clear, very nice to keep it minimal, thumbs up !!

Interesting video's!

David. I just made one from an old microphone (-:
I'll test it later today.

Excellent vid's to watch

I got excited when I read your headline
I thought you had found a way to use a mic without have to buy the expensive (and precariously sticking out) DJI mic dongle !

Oh well maybe someone soon will figure out how to build a small USB-C connected "stubby" mic and also a USB-C lapel mic

Very cool! Nicely done mate

Okay. I just did some testing with my modded lavalier mic and it sounded like sh*t. It sounded like I was in a bathroom and looking at the sound profile it kind of looked like the left and right did not compare 100% to each other.

So. I opened the 3.5 mm (stereo) jack plug again, and disconnected the ring from the sleeve  (so only the tip and ring are used) *** EDIT. Tip and SLEEVE are used!
Guess what. It sounded great!

David. Are you using the ring (middle part of the 3.5 mm stereo plug) with your modified mic?

Very nice DIY project Dave.
I am looking forward to how to make video.

Hello and good day Dave. Thank you for sharing these interesting video with us today. Great work and thank you for your support.

NoëI Posted at 3-25 07:27
Okay. I just did some testing with my modded lavalier mic and it sounded like sh*t. It sounded like I was in a bathroom and looking at the sound profile it kind of looked like the left and right did not compare 100% to each other.

So. I opened the 3.5 mm (stereo) jack plug again, and disconnected the ring from the sleeve  (so only the tip and ring are used)

Hi NoëI.

Yes, I'm normalising tip and ring, which is the opposite to your successful results. I actually get different results compared to yours when only making pole 1, tip, live.

I've done very exhaustive testing of many different mics, wiring and powering/amplification and have very varied outcomes. If I can, I'll try and upload something that you may find interesting and PM you.

Cheers,
Dave.
BTW. I really like your mic build, you can't beat heat shrink or superglue

DJI Stephen Posted at 3-25 07:43
Hello and good day Dave. Thank you for sharing these interesting video with us today. Great work and thank you for your support.

Hi Stephen.

You are very welcome.

BTW. I've just done a video using the Pocket with a wireless lavalier setup. The test scenario was VERY real world and I'm really happy with the results. I'll post links once I have an edit completed.

Cheers,
Dave.

David_Harry Posted at 3-25 11:31
Hi NoëI.

Yes, I'm normalising tip and ring, which is the opposite to your successful results. I actually get different results compared to yours when only making pole 1, tip, live.

David. I just reread my post and what I ment to say was that I'm now using the tip and sleeve, and that it's working great.
Sorry for the confusion I caused.

I'm away from home now, but when I get back I'll PM you.

Thanks for the compliment about the "build".
By the way. I'm missing duct / gaffer tape on your list :-)

David_Harry Posted at 3-25 11:34
Hi Stephen.

You are very welcome.

You are very much welcome Dave. I will be waiting to see that post. We really appreciate how you make this forum very informative. Thank you for your valued support.

David_Harry Posted at 3-25 11:31
Hi NoëI.

Yes, I'm normalising tip and ring, which is the opposite to your successful results. I actually get different results compared to yours when only making pole 1, tip, live.

Dave,

I went ahead and started checking my microphones and found that they are not all wired the same.  The Edutage ETM-001is wired as I think  your EM-172 setup is with Tip to Tip, Sleeve to Sleeve, and Tip tied to Ring.  But, my Lavs are not wired that way.  The A-Lav has nothing connected to the tip and Mic hot is on the ring with ground on the Sleeve.  

I then checked for plug in power coming out of the audio adapter and found it to be a little under 3V with the + side on the ring.   So I built a test rig that I could easily switch connections with and found that the Pocket audio adapter seems happiest when it has an input signal on both the channels (tip and ring) and of course ground (sleeve to sleeve).  

The big thing here seems to be knowing that if you need plug in power it is only available on the ring.

Does that help clear up any of your previous head scratching Dave?  It sure helped for me.
Edit:
I just did some more testing.  Sleeve of mic is always connectecd to Sleeve of adapter input (ground).  When Tip is not connected but Ring of mic is connected to Ring of adapter audio shows up recorded on both channels but the channels are  NOT a true duplicate image of each other (love that invert testing).  When Tip is connected to Tip and Ring is connected to Ring we DO have a duplicate image recorded as proven with no audio output with one channel being inverted.  When either Tip is connected to TIP or Ring is connected to Ring and they are tied together we again DO have a duplicate image recorded.   Just a long way of saying that Osmo Pocket Audio Adapter wants a signal on both channels to be happy and if you need plug-in power you better have some sort of connection to the adapters ring.

And I don't think that the adapter likes it when you feed a signal to the right channel (Ring) but not the left (Tip)  as that was what my A-Lav (minus it's external plug-n power adapter) was doing when I saw distorted audio.  Just feed the left (tip) side and not the right and the Osmo will try to duplicate the signal onto the right side but not as good as feeding mono microphones to both channels.

Tomorrow I will build a couple of 40dB pads so that I can connected the line out of my Zoom H6 into the individual channels using a test recording with seperate audio/silence on each channel in turn to see what that looks like after being recorded by the Osmo Pocket.
Bob

David / Bob,

I'm getting really strange results here. Sometimes the "DIY" mic or any other external mic I own (2) works great, and sometimes it sounds really bad (like being in a bathroom)
I've order an  EM-172, and will rebuild the DIY mic when it arrives.

Noel

BobWinNV Posted at 3-25 19:06
Dave,

I went ahead and started checking my microphones and found that they are not all wired the same.  The Edutage ETM-001is wired as I think  your EM-172 setup is with Tip to Tip, Sleeve to Sleeve, and Tip tied to Ring.  But, my Lavs are not wired that way.  The A-Lav has nothing connected to the tip and Mic hot is on the ring with ground on the Sleeve.  

Hi Bob.
I couldn't remeber the points you raised so I've copied your post and added answers

I went ahead and started checking my microphones and found that they are not all wired the same.  The Edutage ETM-001is wired as I think  your EM-172 setup is with Tip to Tip, Sleeve to Sleeve, and Tip tied to Ring.  But, my Lavs are not wired that way.  The A-Lav has nothing connected to the tip and Mic hot is on the ring with ground on the Sleeve.

The A-Lav is wired in such a way that it triggers its own power module to switch it on when inserted. If you try another lav in the A-Lav's power module you'll probably find that it doesn't get powered.

I then checked for plug in power coming out of the audio adapter and found it to be a little under 3V with the + side on the ring.   So I built a test rig that I could easily switch connections with and found that the Pocket audio adapter seems happiest when it has an input signal on both the channels (tip and ring) and of course ground (sleeve to sleeve).  

The big thing here seems to be knowing that if you need plug in power it is only available on the ring.

Yes, I'd noticed similar myself although I thought it was pole 1/tip hot, although there's a fair chance that I may have wired my test cable wrong, I'm colour blind What's interesting is that the configuration obviously won't power two ECM channels. There's a bunch more stuff that I've noticed but don't really want to go into it on an open forum as I'm now getting results with the Pocket that far out way the technical difficulties. For your own curiosity though, try using a source from an external mixer or something that's able to pan a mono signal.

I was going to do a video about this result and would probably have gotten a whole bunch of extra traffic on my YouTube channel with some crappy click bait title. Honestly, you wouldn't believe the public's appetite for negative crap but when you show something really cool and beneficial, the majority don't give a toss. But like I've already said, I'm more interested in finding the Pockets VERY strong points, I'll leave the other stuff for others.

Plus. No one other than DJI knows exactly what's going on with their hardware and software. As has been proven, and this isn't me being negative or bashing DJI but, as the software and functionality issues of the Pocket at release have been well documented and DJI themselves have all but admitted the failings of the Pocket on release by virtue of fixes via software updates. Just like the fixes and on going refinements to the Pocket's video an UI functionality. It may be a similar case with the audio sub-system and future F/W software updates may open up, fix or introduce new features to the Pocket's external audio capabilities.   

Does that help clear up any of your previous head scratching Dave?  It sure helped for me.
Edit:
I just did some more testing.  Sleeve of mic is always connectecd to Sleeve of adapter input (ground).  When Tip is not connected but Ring of mic is connected to Ring of adapter audio shows up recorded on both channels but the channels are  NOT a true duplicate image of each other (love that invert testing).  When Tip is connected to Tip and Ring is connected to Ring we DO have a duplicate image recorded as proven with no audio output with one channel being inverted.  When either Tip is connected to TIP or Ring is connected to Ring and they are tied together we again DO have a duplicate image recorded.   Just a long way of saying that Osmo Pocket Audio Adapter wants a signal on both channels to be happy and if you need plug-in power you better have some sort of connection to the adapters ring.

And I don't think that the adapter likes it when you feed a signal to the right channel (Ring) but not the left (Tip)  as that was what my A-Lav (minus it's external plug-n power adapter) was doing when I saw distorted audio.  Just feed the left (tip) side and not the right and the Osmo will try to duplicate the signal onto the right side but not as good as feeding mono microphones to both channels.

Yes. It requires a normalised input regrdless of the powering scenario, at least for now. Anything other than that will give a number of odd results, as you've noticed and mentioned.

Tomorrow I will build a couple of 40dB pads so that I can connected the line out of my Zoom H6 into the individual channels using a test recording with seperate audio/silence on each channel in turn to see what that looks like after being recorded by the Osmo Pocket.
Bob

You may want to just try the input set to low, I doubt you'll need any padding ahead of it. To be honest and again not wanting to get too far into it. You'll probably find the input to be way lower than line level at low, moderate and possibly high settings, which is why I doub't you'll need a pad. I suspect you'd probably have more joy getting to certain answer by testing for impedance, hint hint

Cheers,
Dave.

NoëI Posted at 3-26 00:29
David / Bob,

I'm getting really strange results here. Sometimes the "DIY" mic or any other external mic I own (2) works great, and sometimes it sounds really bad (like being in a bathroom)

Hi NoëI.

Your best results are going to be using a source that's normalised tip and ring/poles 1 and 2 hot, as far as the Pocket providing power is concerned.

If you check out the previous reply to Bob there may be stuff in there of interest.

Cheers,
Dave.

David / Bob,

Pin 1 and 2 did the trick! (tip/ring)
Working perfect and (for now) all the time!

Thanks

NoëI Posted at 3-26 07:48
David / Bob,

Pin 1 and 2 did the trick! (tip/ring)

I am glad that you have it working now Noel.

Dave.  Chalk one up for the good guys.

Bob

Bob & NoëI

I'm a bit behind on some videos I have to finish and have got a couple of microphones sent to me to review but I'll try and do some more tests that you both may find interesting.

I've got a load of ECM capsules, I basically buy loads of cheap products and strip them of capsules and parts. The thing is, most of this stuff is really bad but some of the capsules that would otherwise sound terrible sometimes work really well on certain devices. It's just a case of wiring random ones sometimes and see if any work. I basically sit there with a cable and just solder and de-solder  until I find something.

I suspect the sweet spot with the Pocket's interface is something within a certain impedance range.

David_Harry Posted at 3-26 10:59
Bob & NoëI

I'm a bit behind on some videos I have to finish and have got a couple of microphones sent to me to review but I'll try and do some more tests that you both may find interesting.

Keep is posted David!

David_Harry Posted at 3-26 10:59
Bob & NoëI

I'm a bit behind on some videos I have to finish and have got a couple of microphones sent to me to review but I'll try and do some more tests that you both may find interesting.

Thanks Dave.

Dave, I need your advise.

I have an old stereo earphone, 3.5mm TRS, and a mono small microphone for computer, which has 2 terminals there (2 soldering points.

So if I want to cut and throw away the ear pieces, connect the remaining plug and wires to the mic like your nano mic, is the correct connection are: L & R to one soldering point of the mic and both ground wire to other soldering point? And the result will be a simple mono mic that works with the DJI audio adapter?

Oh-no Posted at 3-28 07:52
Dave, I need your advise.

I have an old stereo earphone, 3.5mm TRS, and a mono small microphone for computer, which has 2 terminals there (2 soldering points.

Hi.

Yes, what you've described is exactly how to do it. Just make sure that you are definitely using ground on the mic.

I always buy cheap bad quality earbuds  and head sets for this exact reason. Because the jack end of the headset is molded and the cabling is of good enough quality, it makes it easier as I don't have to solder the jack end.

I also build TRS to TRRS and XLR to TRRS with the same method but use the thinnest cable I can find. I then use these cables to connect a mic to a phone on a gimbal. I hang the mic at the bottom of the gimbal, most usually have a quarter/20 hole, I then run the cable up the gimbal holding it in place with elastic bands then fix the cable the rear motor arm with an elastic band and then connect to the phone's TRRS socket. This means very little extra resistance to the motors and being able to mount very high quality mics to the gimbal.

I also do similar with lavalier mics as well.

This method would work perfectly for DJI gimbals.

Cheers,
Dave.

Thank you again Dave, you are always helpful :-)

Well, mission accomplished.
Next step is thinking how to DIY the dead cat, covers the pink part as well.....

No luck ... DIY dead cat failed ..... need to buy one .... use the foam cover for now ......

Final look .   :-)

Oh-no Posted at 3-28 12:11
Final look .   :-)

[view_image]

Hi.

That looks awesome, yours is all one colour and looks like a proper mic, mine is a proper botch job and defo looks like two things stuck together   You'll have to post some tests.

Oh-no Posted at 3-28 12:11
Final look .   :-)

[view_image]

That looks great Oh-no.  I am looking forward to see how it sounds as well.
Bob

David_Harry Posted at 3-28 14:30
Hi.

That looks awesome, yours is all one colour and looks like a proper mic, mine is a proper botch job and defo looks like two things stuck together   You'll have to post some tests.

The black thing is a an add on sleeve made from a ball pen sleeve...  :-)  

Sure I will make some test when the audio adapter arrives in next few days.

BobWinNV Posted at 3-28 14:57
That looks great Oh-no.  I am looking forward to see how it sounds as well.
Bob

I did test it with my digital recorder, it feeds mono sound to both channels, hope it works on the OP audio adapter as well.

Oh-no Posted at 3-28 18:04
I did test it with my digital recorder, it feeds mono sound to both channels, hope it works on the OP audio adapter as well.

That is a great start.  Let us know how it works after you can test it with your OP.

Bob

BobWinNV Posted at 3-28 18:09
That is a great start.  Let us know how it works after you can test it with your OP.

Bob

Yeah, I am happy with it at the moment, thus it cost very little because it were all from parts bin and DIY .....

I am planning to do three tests when the audio adapter arrives.

1. solo DIY mic to the OP.
2. connect the digital stereo recorder line out to OP to test if stereo works.
3. connect Nokia BH-218 bluetooth headset output to OP, receive sound from another bluetooth transmitter with feed from digital recorder output.

(2) and (3) is kind of set up to have a backup recorded sound file.
The bluetooth transmitter not working with the solo DIY mic, due to the mic is non-powered.

Oh-no Posted at 3-28 18:25
I am planning to do three tests when the audio adapter arrives.

1. solo DIY mic to the OP.

Well, let us know how your tests go.  I hope that you get your adapter soon.
Bob

I bought two little microphones from TaoBao.com @ US$1.35/pc.