Osmo Pocket mic adaptor, TS or TRS?
3804 14 2019-3-14
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David_Harry
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Hi.

Could anyone from DJI or anyone who has the adaptor confirm if it's wired TS ot TRS please?

If TRS, is it stereo or mono normalised?

Does it have to be activated as a peripheral from within the Pocket's menu, or does it switch to it straight away when it's inserted?

Is the resulting recording stereo, dual mono or mono normalised across two channels?

Are there any extra functions in the UI when the adaptor is plugged in?

Does it record PCM or is it still AAC, if AAC what bitrate?

Is the input completely variable or is still the same gain options as the internal mics?

What voltage does it supply?

Does it have any extra dynamics processing, if so, what is the limiter set to for its ceiling?

Does it sound any good with a pro dialogue mic shotgun/cardioid etc.?

Cheers,
Dave.




2019-3-14
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BobWinNV
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It’s TRS.

I am still waiting for mine to ship so I can’t  accurately  answer any of your other questions yet.

Bob
2019-3-14
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Gr8fulTed
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David Harry, just watched your homemade windsock YouTube video. Epic.
2019-3-14
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David_Harry
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BobWinNV Posted at 3-14 17:40
It’s TRS.

I am still waiting for mine to ship so I can’t  accurately  answer any of your other questions yet.

Hi Bob.

If you could add any further info when you've had time to test yours, that would be awesome thanks.

I think one thing that would really help users is if DJI add some basic info as a sticky to the forum. Depending on the cofiguration, TS/TRS, it will impact quite heavily what kind of mics that people can use.

Cheers,
Dave.
2019-3-14
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David_Harry
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Gr8fulTed Posted at 3-14 17:54
David Harry, just watched your homemade windsock YouTube video. Epic.

Hi. I'm glad you liked the video, hopefully it was helpful and maybe give you some ideas.

Cheers,
Dave.
2019-3-14
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Ray-CubeAce
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Hi.

Could anyone from DJI or anyone who has the adaptor confirm if it's wired TS ot TRS please?

TRS

If TRS, is it stereo or mono normalised?

No real idea as yet but def, not stereo

Does it have to be activated as a peripheral from within the Pocket's menu, or does it switch to it straight away when it's inserted?

Switches straight away

Is the resulting recording stereo, dual mono or mono normalised across two channels?



Are there any extra functions in the UI when the adaptor is plugged in?

No, but you can see the record level in the app

Does it record PCM or is it still AAC, if AAC what bitrate?

AAC and the same

Is the input completely variable or is still the same gain options as the internal mics?

Same as internal mics

What voltage does it supply?

Does it have any extra dynamics processing, if so, what is the limiter set to for its ceiling?

Does it sound any good with a pro dialogue mic shotgun/cardioid etc.?

Sounds great
2019-3-15
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David_Harry
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Ray-CubeAce Posted at 3-15 00:26
Hi.

Could anyone from DJI or anyone who has the adaptor confirm if it's wired TS ot TRS please?

Hi Ray.

That's awesome thanks. Maybe once we have more user experience like yours any potential new purchasers will be better informed before buying. Or maybe DJI will list the specs for the adaptor.

How are you finding it? Have you had any issues with it? I've just posted an example by another YouTuber that clearly shows a huge issue with it.

Cheers,
Dave.
2019-3-15
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dewarner
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I received mine yesterday, and it works fine connected directly to the Osmo Pocket.  Does anyone know if it is supposed to work with the WiFi adapter in use?  So far, it does not seem like it does.

Thanks -
2019-3-15
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fans737ad63c
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Ray-CubeAce Posted at 3-15 00:26
Hi.

Could anyone from DJI or anyone who has the adaptor confirm if it's wired TS ot TRS please?

Just to confirm that it is TRS. Worked straight away with Røde mini mic. Sounds excellent.
The only problem that has now been thrown up is how to mount the mic, if you’re not using a lav mic.
I’ve been using a PGYTECH phone holder with the OP mounted on the side. There is a cold shoe mount on top of the unit, but once the mic is attached, you obviously can’t pan the OP left, since the mic will come into shot. I need to find another option...
2019-3-15
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Ray-CubeAce
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fans737ad63c Posted at 3-15 03:14
Just to confirm that it is TRS. Worked straight away with Røde mini mic. Sounds excellent.
The only problem that has now been thrown up is how to mount the mic, if you’re not using a lav mic.
I’ve been using a PGYTECH phone holder with the OP mounted on the side. There is a cold shoe mount on top of the unit, but once the mic is attached, you obviously can’t pan the OP left, since the mic will come into shot. I need to find another option...

Ha! Same here.
2019-3-15
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dmwierz
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dewarner Posted at 3-15 03:07
I received mine yesterday, and it works fine connected directly to the Osmo Pocket.  Does anyone know if it is supposed to work with the WiFi adapter in use?  So far, it does not seem like it does.

Thanks -

Sadly, it does not work with the WiFi Adapter. You still get audio, but it's from the Osmo Pocket's internal microphone.

Not sure this can even be updated via firmware, as it would appear that the USB-C port on the rear of the WiFi adapter is power only, and not data.

I will be doing a complete review of the Mic Adapter this weekend, and will post a link in this forum, including tests with the WiFi adapter, a mini shotgun mic, a wired lav and two wireless mics.
2019-3-15
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Joemar7
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It's ridiculous that DJI does not provide the mic adapter specs in their website and that we need to run tests ourselves to determine those specs.  If a DJI admin is reading this, hopefully they can disclose more about it.  1. Stereo?  2.  Bitrate?  3.  Does it work with the wireless adapter?  Come on DJI.  Everyone is asking the same questions even on Facebook.   
2019-3-15
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Ray-CubeAce
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I'm halfway through my testing the audio adapter using a self-powered (3v) electret stereo microphone with variable pickup patterns and the Osmo Pocket left on its auto volume control.
Some things I can say already.
Avoid any stereo mic that only has capsules facing away from each other at 180 degrees. Although the wide setting on my mic is a figure of eight pickup pattern it gives the lowest output values coming in an average reading of less than -32dBm at normal speaking levels at about eighteen inches from me when speaking normally.
A normal stereo XY-axis with capsules at 90 degrees to each other gives a reading of around -28dBm.
A hyper-cardioid pickup pattern gives an output of around -10dBm.
So it would seem that the use of a microphone with a built-in preamp should be needed for voice recording unless you happen to have a loud voice or use your microphone closer.
For amplified concert music you may get away with any normal standard stereo mic or mono hyper-cardioid (With a strereo connector) for best volume output.
Having only one channel plugged in (either one) does give an output to both channels (Confused?) but at very low levels of below -40dBm.
Whether in stereo or recording from a mono mic, neither channel is identical in output to the other all the time. Sometimes the waveforms invert from each other or slightly delay on the left-hand channel, while the right-hand channel always seems to have a boost of at least 2 to 4 dBm over the left.  Although I say left and right channels I have no idea which is which due to the odd behavior of the Osmo Pocket's output.
I would be wary of using built-in pre-amped mics as there is no way beyond using automated level control to keep things under control with loud transients but there is no evidence of volume pumping and seems well controlled. When I've finished the video I will put it up on this forum for you to draw your own conclusions and see if I have made any glaring errors.
2019-3-16
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David_Harry
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Ray-CubeAce Posted at 3-16 05:30
I'm halfway through my testing the audio adapter using a self-powered (3v) electret stereo microphone with variable pickup patterns and the Osmo Pocket left on its auto volume control.
Some things I can say already.
Avoid any stereo mic that only has capsules facing away from each other at 180 degrees. Although the wide setting on my mic is a figure of eight pickup pattern it gives the lowest output values coming in an average reading of less than -32dBm at normal speaking levels at about eighteen inches from me when speaking normally.

Hi Ray.

Thanks for the very detailed response, I'm sure this will be  invaluable information for other Pocket users thinking about getting the mic adaptor or users who already have one and need some tips for best usage. I'm really looking forward to your final video example.

So far from what I've seen around the forum and the web, there seems to be many issues with this interface. By the looks of how bulky the interface is, it does look like it's got some active circuitry in it, possible an IC that's doing the A to D. In any event, I've heard some pretty bad audio examples with good mics, which does suggest that the DJI audio sub-system isn't very good.

If I had to guess I'd say the first issue with the interface is one of impedance, which could also explain why an otherwise good microphone doesn't sound so good and low on the adaptor.

That annomoly you describe between the two channels, one maybe slightly inverted and possibly a time difference, sounds like what I'd described with the internal mics where you almost get a sense of width with noise but dialogue is centred. Again, as I'd suggested in that initial appraisal, there could be time/phase issues introduced at the encoding stage as it's encoded to two channels. If this is the case, it would effect both a mono and stereo source as both are being encoded to two channels. In any event, you are describing something very similar, if not the same, as what I'd noticed.

It may even be the case that an external source is being unnesseraly treated the same way that the internal mics are, with the same cancellation and dynamics processing.

I'm still not sure that it is recording stereo properly, I've a feeling that it's some kind of a difference encoding, or it's simply not stereo and recording strange anomalies.

If you get time maybe try recording a stereo source, say a CD player or stereo music source like a phone's headphone headphone output and just plug them straight into the interface. This will be the only definitive way of knowing for sure if it's recording true stereo. Centring both channels and reversing the phase of one will also give you some straight answers.

Even before the jury's out on this one I think it's safe to say that at the very least this interface is problematic and at worse is going to be unusable for many people wanting professional audio/dialogue/microphone results.

I wonder if those people who were using the GoPro interface to justify the price of the DJI interface would still say the same thing now. I've not heard one example yet of the DJI interface that comes close to the quality of the GoPro one and we also now know that the DJI interface has nowhere near the audio or technical abilities of the GoPro interface.

Anyway. Thanks again Ray for your efforts, they're greatly appreciated and will help others.

Cheers,
Dave.  
2019-3-16
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Ray-CubeAce
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David_Harry Posted at 3-16 07:57
Hi Ray.

Thanks for the very detailed response, I'm sure this will be  invaluable information for other Pocket users thinking about getting the mic adaptor or users who already have one and need some tips for best usage. I'm really looking forward to your final video example.

Hi Ray.

Thanks for the very detailed response, I'm sure this will be invaluable information for other Pocket users thinking about getting the mic adaptor or users who already have one and need some tips for best usage. I'm really looking forward to your final video example.

I should have it ready soon. Rendering it now.

So far from what I've seen around the forum and the web, there seem to be many issues with this interface. By the looks of how bulky the interface is, it does look like it's got some active circuitry in it, possibly an IC that's doing the A to D. In any event, I've heard some pretty bad audio examples with good mics, which does suggest that the DJI audio sub-system isn't very good.

If I had to guess I'd say the first issue with the interface is one of impedance, which could also explain why an otherwise good microphone doesn't sound so good and low on the adaptor.

My test mic is low impedance.

That anomaly you describe between the two channels, one may be slightly inverted and possibly a time difference, sounds like what I'd described with the internal mics where you almost get a sense of width with noise but the dialogue is centered. Again, as I'd suggested in that initial appraisal, there could be time/phase issues introduced at the encoding stage as it's encoded to two channels. If this is the case, it would affect both a mono and stereo source as both are being encoded to two channels. In any event, you are describing something very similar, if not the same, as I'd noticed.

I thought the same. I first noticed with the internal mics when passing a stream. The water flow sounded really off.

It may even be the case that an external source is being unnecessarily treated the same way that the internal mics are, with the same cancellation and dynamics processing.

Didn't the original testers complain about handling noise and wasn't there a software update before the public versions were shipped to 'improve the signal quality'?  Could that now be reversed?

I'm still not sure that it is recording stereo properly, I've got a feeling that it's some kind of a difference encoding, or it's simply not stereo and recording strange anomalies.

Wait till my video comes out. Maybe more questions than answers.

If you get time maybe try recording a stereo source, say a CD player or stereo music source like a phone's headphone output and just plug them straight into the interface. This will be the only definitive way of knowing for sure if it's recording true stereo. Centering both channels and reversing the phase of one will also give you some straight answers.

I personally daren't. My smartphone is not a tested one and although I can get it to work with my phone, only reliably with the base connector. So I can't monitor sound levels and have the mic adaptor in use at the same time. Sorry.

Even before the jury's out on this one, I think it's safe to say that at the very least this interface is problematic and at worse is going to be unusable for many people wanting professional audio/dialogue/microphone results.

Yes and No.

I wonder if those people who were using the GoPro interface to justify the price of the DJI interface would still say the same thing now. I've not heard one example yet of the DJI interface that comes close to the quality of the GoPro one and we also now know that the DJI interface has nowhere near the audio or technical abilities of the GoPro interface.

Haven't had the experience with a GoPro although my son stopped using his in favour of the Osmo Pocket. He actually likes the inboard mics for what he does.

Anyway. Thanks again Ray for your efforts, they're greatly appreciated and will help others.

I had hoped that as well, will wait and see what the response is like later.

Cheers,
Dave.  
       
2019-3-16
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