Blackmagic pocket 4k preamp question

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anneboyer

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Blackmagic pocket 4k preamp question

PostWed Jul 24, 2024 9:24 pm

Hi. I wanted to know, what is the max db range on the pocket 4k preamps for clean sound? It's gotta be way less than 100 db because it mostly sounds crap. I guess 60-80 db? Asking cause I may need to record audio only from camera connected mic for a personal project.
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Alex Mitchell

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Re: Blackmagic pocket 4k preamp question

PostThu Jul 25, 2024 5:19 am

To the best of my knowledge BMD doesn't publish that info on their site or in their manuals. Would recommend just reaching out directly to their support team and asking for the info. They really should be publishing it somewhere, for sure.
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostThu Jul 25, 2024 8:32 am

anneboyer wrote:Hi. I wanted to know, what is the max db range on the pocket 4k preamps for clean sound? It's gotta be way less than 100 db because it mostly sounds crap. I guess 60-80 db? Asking cause I may need to record audio only from camera connected mic for a personal project.


I record audio all the time into my PCC4k and it doesn't sound crap.
If you use the built-in mic - then yes, that does sound bad.
Saying "Thx for help!" is not a crime.
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anneboyer

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Re: Blackmagic pocket 4k preamp question

PostThu Jul 25, 2024 4:27 pm

Robert Niessner wrote:
anneboyer wrote:Hi. I wanted to know, what is the max db range on the pocket 4k preamps for clean sound? It's gotta be way less than 100 db because it mostly sounds crap. I guess 60-80 db? Asking cause I may need to record audio only from camera connected mic for a personal project.


I record audio all the time into my PCC4k and it doesn't sound crap.
If you use the built-in mic - then yes, that does sound bad.


Well it is not good even with a connected microphone. I get it cause it's a camera, audio ain't its specialty. But I curious to know its preamps limits. Even an old zoom h1n will do a 100x better job I guess.
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anneboyer

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Re: Blackmagic pocket 4k preamp question

PostThu Jul 25, 2024 4:28 pm

Alex Mitchell wrote:To the best of my knowledge BMD doesn't publish that info on their site or in their manuals. Would recommend just reaching out directly to their support team and asking for the info. They really should be publishing it somewhere, for sure.


I really expected this info to be there and was shocked that bmd did not ever publish this anywhere.
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostThu Jul 25, 2024 6:42 pm

anneboyer wrote:
Robert Niessner wrote:
anneboyer wrote:Hi. I wanted to know, what is the max db range on the pocket 4k preamps for clean sound? It's gotta be way less than 100 db because it mostly sounds crap. I guess 60-80 db? Asking cause I may need to record audio only from camera connected mic for a personal project.


I record audio all the time into my PCC4k and it doesn't sound crap.
If you use the built-in mic - then yes, that does sound bad.


Well it is not good even with a connected microphone. I get it cause it's a camera, audio ain't its specialty. But I curious to know its preamps limits. Even an old zoom h1n will do a 100x better job I guess.


I’ve done professional productions with it that way since 2018. Interviews on the go with a Rode Reporter and a Sennheiser EW 100 wireless set into the 3.5mm input. More complex interviews with a Schoeps Colette directly into the mini XLR. Or a Rode NTG-3. For location sound a Rode VideoMic NTG on camera.

So please stop telling me you can’t get good sound.

What is your setup, what are you trying to accomplish? Can you post samples of your bad sound?
Saying "Thx for help!" is not a crime.
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Howard Roll

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Re: Blackmagic pocket 4k preamp question

PostThu Jul 25, 2024 8:08 pm

Save your outrage. The Pocket 4k audio input limit is listed on the specs page. +14 dbu or about 3.88v RMS. 60-80db is a measure of SPL, a completely different animal though both use decibels. For example 80db of SPL could produce -20 or -40dbu, it all depends on the capsule.

Good Luck
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anneboyer

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 4:50 am

Robert Niessner wrote:I’ve done professional productions with it that way since 2018. Interviews on the go with a Rode Reporter and a Sennheiser EW 100 wireless set into the 3.5mm input. More complex interviews with a Schoeps Colette directly into the mini XLR. Or a Rode NTG-3. For location sound a Rode VideoMic NTG on camera.

So please stop telling me you can’t get good sound.

What is your setup, what are you trying to accomplish? Can you post samples of your bad sound?


Look, I have never used it as my recorder. I've used my h1n in the past for my own shoots. I am mainly an editor. The shoots I am talking about are journey vlog sort of videos. I know how I set the gain on other recorders. The gain on this thing especially when connected to the 3.5mm mic in, sucks on either end. It clips easily on one hand or is too low on the other end. This time, I was trying to reduce as much equipment as I could. I'll prolly just buy a point and shoot some point in the future or an autofocus ibis camera. But you can't rely on this thing for its audio recording in any professional production. You oughta use a good sound recorder. Good for you that you got good professional audio from this.
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 5:14 am

anneboyer wrote:
Robert Niessner wrote:I’ve done professional productions with it that way since 2018. Interviews on the go with a Rode Reporter and a Sennheiser EW 100 wireless set into the 3.5mm input. More complex interviews with a Schoeps Colette directly into the mini XLR. Or a Rode NTG-3. For location sound a Rode VideoMic NTG on camera.

So please stop telling me you can’t get good sound.

What is your setup, what are you trying to accomplish? Can you post samples of your bad sound?


Look, I have never used it as my recorder. I've used my h1n in the past for my own shoots. I am mainly an editor. The shoots I am talking about are journey vlog sort of videos. I know how I set the gain on other recorders. The gain on this thing especially when connected to the 3.5mm mic in, sucks on either end. It clips easily on one hand or is too low on the other end. This time, I was trying to reduce as much equipment as I could. I'll prolly just buy a point and shoot some point in the future or an autofocus ibis camera. But you can't rely on this thing for its audio recording in any professional production. You oughta use a good sound recorder. Good for you that you got good professional audio from this.


Yes, the gain is on the low end and needs a hotter feed, but your assessment that you can’t rely on it for audio recording in any professional production is just not true.
You still fail to list your setup and didn’t post samples of the bad sound.

Did you came here to find a solution or just for a rant?
Saying "Thx for help!" is not a crime.
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anneboyer

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 6:03 am

Robert Niessner wrote:Yes, the gain is on the low end and needs a hotter feed, but your assessment that you can’t rely on it for audio recording in any professional production is just not true.
You still fail to list your setup and didn’t post samples of the bad sound.

Did you came here to find a solution or just for a rant?


why would I come to rant about a camera that is so cheap and good??? Sorry I should say my setup is the deity vmic d3 plugged right into the camera. I haven't actually done any recording, I was testing this with my friend in front of the cam to see levels while monitoring it with an in ear headphone. Maybe I just don't know how to set gain level on this camera. I never had trouble setting gain on the good old h1n.
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 8:14 am

If you are planning to record voice with the mic on the camera, then yes levels will be quite low.
When I record voice the mic is always as close to the speaker as possible.

As the audio inputs do have no auto-leveling whatsoever, you will need to adjust the volume manually.
I’ve no experience with the Deity, but from its specs it has a sensitivity of -35 dBV/Pa vs. the Rode Videomic NTG with -26 dBV/Pa. That’s a difference of almost 12dB.
Also the output impedance of the Deity is 200Ω vs. 10Ω on the Rode.

So my conclusion is the Rode would be a better fit for this camera.

In my experience you can boost the gain quite high in post without adding too much noise.
Saying "Thx for help!" is not a crime.
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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 8:17 am

Robert Niessner wrote:If you are planning to record voice with the mic on the camera, then yes levels will be quite low.
When I record voice the mic is always as close to the speaker as possible.

As the audio inputs do have no auto-leveling whatsoever, you will need to adjust the volume manually.
I’ve no experience with the Deity, but from its specs it has a sensitivity of -35 dBV/Pa vs. the Rode Videomic NTG with -26 dBV/Pa. That’s a difference of almost 12dB.
Also the output impedance of the Deity is 200Ω vs. 10Ω on the Rode.

So my conclusion is the Rode would be a better fit for this camera.

In my experience you can boost the gain quite high in post without adding too much noise.


I would love to get the mic as close to subjects as possible but how do you even do that when run and gunnin? Solo
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 8:24 am

Yes, that’s an understandable objection. As I said I think the Rode would be a better fit for your use case.
You also might consider something like the Rode Wireless Go II Pro so you could put a lav mic onto your friend when vlogging. The whole Wireless Go system has a tiny footprint.

I’ll do some audio tests for you with my PCC4K and the Rode Videomic NTG with different gain settings so you can see if this would work for you.
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 2:43 pm

I made the following test setup:

Went into the most silent room I have - room tone is 28dBA.
Used an iPad playing a sine wave at 1 kHz in about 1 m away, at 60dBA.

PCC6k Pro with Rode Videomic NTG into 3.5mm L+R with its foam windshield.
Mic set to full loudness at 15 and the high-shelf set to ON.

Camera input levels set at: +65dB and then for each recording reduced by -6dB down to +11dB
Which results in 10 recordings, a few seconds of silence and then with the sine wave.

The timeline looks like this:
Timeline Sinus 1kHz.png
Timeline Sinus 1kHz.png (332.81 KiB) Viewed 2471 times


Exported the individual audio files as 32bit WAV for further analysis in iZotope RX Advanced.
Each file got filtered with an EQ high pass at 80Hz 24db/oct to remove the low frequency room tone and handling noise. Individual gain was applied to each clip (except the first one) so that the sine wave reaches -8.9dB - taking the first clip as the reference level.

A005_07261038_C019 Audio Extrahiert.jpg
The first recording with camera level +65dB
A005_07261038_C019 Audio Extrahiert.jpg (843.04 KiB) Viewed 2471 times


A005_07261043_C027 Audio Extrahiert.jpg
The last recording with camera level +11dB and post gain applied (+43,20 dB)
A005_07261043_C027 Audio Extrahiert.jpg (834.34 KiB) Viewed 2471 times


Note: because I moved my hand back from the iPad to the camera there is this small hill in the sine wave from sound reflecting of my hand/body.

Then I used the spectrum analyzer for a sample and for long term window (to get an average).
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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 2:53 pm

The spectrum for the first clip at sample level:
A005_07261038_C019 Audio Extrahiert Short.png
A005_07261038_C019 Audio Extrahiert Short.png (222.12 KiB) Viewed 2467 times


The spectrum for the first clip at a longer window level:
A005_07261038_C019 Audio Extrahiert Long.png
A005_07261038_C019 Audio Extrahiert Long.png (105.11 KiB) Viewed 2467 times


You can see that from 2 kHz on the noise sits at -90dB and goes a bit up in the highs.
500 Hz sits at -85dB, 200 Hz at -76dB and 100 Hz at -60dB
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 3:00 pm

The spectrum for the last clip at sample level:
A005_07261043_C027 Audio Extrahiert Spectrum Short.png
A005_07261043_C027 Audio Extrahiert Spectrum Short.png (221.77 KiB) Viewed 2464 times


The spectrum for the last clip at a longer window level:
A005_07261043_C027 Audio Extrahiert Spectrum Long.png
A005_07261043_C027 Audio Extrahiert Spectrum Long.png (105.82 KiB) Viewed 2464 times


You can see that from 2 kHz on the noise still sits at -90dB and goes a bit up (-93dB) in the highs.
500 Hz sits at -79dB, 200 Hz at -71dB and 100 Hz at -53dB

So by applying post gain for the lowest level recording you add 6 to 7dB on the lower end and 3dB in the highs. Not quite dramatic, I'd say.
Saying "Thx for help!" is not a crime.
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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 3:56 pm

I've got to agree with Robert on this.

No it's not a Sound Devices 833 or Mix Pre. But I've found recording audio to the camera does an similar job as the low-end Zooms at least IMHO.

If you're using the argument that you need a pro audio recorder then you could take it a step farther that you need an audio operator as well. Well when I can afford it that's exactly what I do. But on most occasions sadly that's not the case.

It took me a while to realize and trust that for one or even two mic situations the audio recorded on camera came out well.
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Re: Blackmagic pocket 4k preamp question

PostFri Jul 26, 2024 8:40 pm

Robert Niessner wrote:
You can see that from 2 kHz on the noise still sits at -90dB and goes a bit up (-93dB) in the highs.
500 Hz sits at -79dB, 200 Hz at -71dB and 100 Hz at -53dB

So by applying post gain for the lowest level recording you add 6 to 7dB on the lower end and 3dB in the highs. Not quite dramatic, I'd say.


Beautiful, that's very detailed, thank you for all that trouble. I am also leaning towards the Rode and these tests help me a lot to prepare for my journey and travel videos. Adding 6 to 7 db on the low end and 3db to the highs is really not that dramatic as I imagined it would be. That means I can afford to set a lower gain and not risk clipped audio.
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Re: Blackmagic pocket 4k preamp question

PostSat Jul 27, 2024 11:17 am

I'll echo the Rode Wireless Pro suggestion. Follow Rode's guide on setting it up for BMPCCs and it records quite acceptable audio on-camera. I see the Rode Wireless units used a lot on street interviews from the BBC - one unit to clip to a jacket and, for that situation, it does a good job. The current versions also give a 32bit recording on the transmitters (up to 40 hours worth, according to the Rode specs I've read) - so no fear regarding wireless drop-out or interference (and insurance against setting the on-camera audio incorrectly).

I also have the Rode Videomic NTG - not often used since I upgraded my original Wireless Go to Wireless Pro, but always gives good, clean sound when it is used. It's my goto if I need something better than the onboard mics on-board.
16" MacBookPro (2024; M4Max; 48GB RAM)
DV Resolve Studio 20
BMPCC 6kG2, Canon EF 16-35mm1:2.8L II (usually)
BMPCC 4k, Meike 16mm
Rode Wireless Pro and VideoMicNTG mics; Tascam X8 field recorder
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Re: Blackmagic pocket 4k preamp question

PostSat Jul 27, 2024 4:26 pm

Steve@Aberdeen wrote:I'll echo the Rode Wireless Pro suggestion. Follow Rode's guide on setting it up for BMPCCs and it records quite acceptable audio on-camera. I see the Rode Wireless units used a lot on street interviews from the BBC - one unit to clip to a jacket and, for that situation, it does a good job. The current versions also give a 32bit recording on the transmitters (up to 40 hours worth, according to the Rode specs I've read) - so no fear regarding wireless drop-out or interference (and insurance against setting the on-camera audio incorrectly).

I also have the Rode Videomic NTG - not often used since I upgraded my original Wireless Go to Wireless Pro, but always gives good, clean sound when it is used. It's my goto if I need something better than the onboard mics on-board.


This gets us into the problem of how exactly do I get my mic as close to my subject as possible without sticking the camera in their face? I have seen some product called Zacuto microboom, maybe that can work, not sure about the durability of the whole thing. I can't be goin around laving every next person I meet on the journey.
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Re: Blackmagic pocket 4k preamp question

PostSat Jul 27, 2024 10:17 pm

anneboyer wrote:I can't be goin around laving every next person I meet on the journey.


No, probably not, but you're not going to stick your camera in the face of someone you just met 10 seconds ago either (ostensibly). Takes about a minute to hang a lav on someone. If you're shooting someone for more than a minute it may be worth taking the time to get the best audio you can. Using both is likely the optimal solution.

Good Luck
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Robert Niessner

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Re: Blackmagic pocket 4k preamp question

PostSun Jul 28, 2024 6:31 am

You could just clip the Wireless Go transmitter onto somebody, it has a built-in mic. And you can get different mounting accessories like magnets for it. Takes a few seconds to place that.
Saying "Thx for help!" is not a crime.
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Robert Niessner
LAUFBILDkommission
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Blackmagic Camera Blog (German):
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Read the blog in English via Google Translate:
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Re: Blackmagic pocket 4k preamp question

PostSun Jul 28, 2024 6:39 am

Howard Roll wrote:
anneboyer wrote:I can't be goin around laving every next person I meet on the journey.


No, probably not, but you're not going to stick your camera in the face of someone you just met 10 seconds ago either (ostensibly). Takes about a minute to hang a lav on someone. If you're shooting someone for more than a minute it may be worth taking the time to get the best audio you can. Using both is likely the optimal solution.

Good Luck


Yes, that's true. That's really why I considered that microboomy thing by Zacuto. I think I am gonna figure it out and make a decision very soon before I prep and leave.
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Re: Blackmagic pocket 4k preamp question

PostSun Jul 28, 2024 6:42 am

Robert Niessner wrote:You could just clip the Wireless Go transmitter onto somebody, it has a built-in mic. And you can get different mounting accessories like magnets for it. Takes a few seconds to place that.


Much as I'd like to use that thing, it looks terrible like this black square thingy sticking out of someone's shirt. I am considering Zacuto microboom but currently it is overpriced at $240 or somethin. I may just decide to use the NTG on camera and deal with sound in post to remove noise using fairlight and plugins. But geez I wish the microboomy thing was not that terribly priced.
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Re: Blackmagic pocket 4k preamp question

PostSun Jul 28, 2024 6:15 pm

We use the Godox wireless mic set for that. Two wireless little square mic things and a receiver attached to the camera.

With both clips and magnet to attach the mics to clothing. And little lavs to plug into them if you prefer. Or of course just hold the mics close to the mouth.

Also, you can use a shotgun on camera or boom.

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