- Posts: 5
- Joined: Sun Apr 21, 2024 8:11 am
- Real Name: Daniel Erickson
I have seen similar posts about this before with other BMD cameras and am waiting to see any responses that address the issue with specific examples. At the very least I would like to hear from Blackmagic camera owners that this is what they are experiencing or no, that sounds broken. To me it seems broken. I’ll start with the general with specifics below.
Checking these forums I have found what seems like the same problem and the responses they have received are vague, at best:
Responses stating that you should always be shooting dual system sound so it doesn’t matter whether or not the inputs are any good.
Responses stating that the mic they used was too weak so they should use a mic with a battery.
Responses stating that the 3.5mm jack preamps are “notoriously bad” and they should use the phantom powered mini-xlr jacks instead.
Responses stating that there is a repeatable known issue where the audio cuts out when the gain is raised too high. (From 2019 but erupted in 2023)
I have tried all of these and are having the same problem with every “solution.”
Here is what I am experiencing:
When I received the camera I immediately charged a battery, put in a card, put on a lens and shot some test shots of my sons sawing wood for their pinewood derby cars. I checked that it was set to camera audio left and right for the inputs. I left the gain at the default. I just wanted to see what I would gety right out of the box.
I was no more than 4 feet away due to space limitations. They were talking at a normal speaking volume for 8 and 11 year old boys and, as I said, sawing wood. I also would talk to them over the sound of the sawing from right behind the handheld camera.
When I reviewed the footage at first I thought there was no sound at all but, with headphones on I can barely hear it. I then tried a few things in my house while my family was watching TV. I noticed that the meters never went above around -40dB. With headphones plugged into the camera, I could barely hear anything either. Yes, I was plugged into the headphone jack, not the microphone jack. With the gain turned all the way up (+6dB for the on camera setting) I get levels of around -30ish to -25dB.
I then tried a microphone in the 3.5mm jack - the RodeVideoMicro and set the inputs to 3.5mm - mic left and right. I got the same results. If I increase the gain to get the levels into the -6dB range I got significant background noise.
I have made several calls to Blackmagic customer service with various results:
The first person I talked to suggested I update to the latest firmware - no change
The second person kept insisting that there is no “normal” sound level and of course I would have to adjust input levels depending on the should level of my subject. Not addressing the issue that I could not hear my subject at all unless I “adjusted” my input levels all the way up.
Since all of this was just quick “living room” tests I decided to do more controlled tests.
I tested the following:
RodeVideoMicro - into 3.5mm
RodeVideoMic NTG (mic built in gain set at manufacturer rec’d 10)- into 3.5mm
Rode NTG-2 - into mini-xlr using a battery in the mic
Rode NTG-2 - into mini-xlr using +48v phantom power
Sennheiser MKE400 - into 3.5mm
Zoom H4n - using it only as a microphone into 3.5mm
Zoom H4n - using it as an audio interface between microphone and camera into 3.5mm
RodeVideoMic NTG into Zoom
Sennheiser e200 GW wireless into Zoom
I tested all of these mics in the following way:
1. Record at the default input level on the camera, noting what the audio meters were reading.
2. Record at whatever gain increase I needed to get the audio meters to land around -6dB (or as close as I could get. Some never got there.)
I then took those files into DaVinci Resolve. I raised the low audio level files to see what it would take to bring them up to around -6dB and hear what noise it added.
This is already an enormously long post so I’ll just sum up my findings. What I discovered is that ALL microphone levels regardless of input method were so low that their input levels needed to be raised to the maximum and for the on-board microphone, even that wasn’t enough.
The only setup that resulted in “normal” expected audio levels was when I either used the Zoom H4n as a microphone or routed the microphones through the Zoom H4n. My assumption is that this method utilizes the Zoom’s preamps rather than every other method using the Blackmagic preamps.
If that’s what people mean by saying that the onboard preamps are “notoriously bad” it seems a little out of spec from what any other camera manufacturer considers normal. I have never, in my years of using audio/video equipment run into this kind of audio issue.
I will render and post my tests if anyone is interested and, hopefully we can quantify the problems I and others are having and maybe we can finally get an apples-to-apples conversation.
Checking these forums I have found what seems like the same problem and the responses they have received are vague, at best:
Responses stating that you should always be shooting dual system sound so it doesn’t matter whether or not the inputs are any good.
Responses stating that the mic they used was too weak so they should use a mic with a battery.
Responses stating that the 3.5mm jack preamps are “notoriously bad” and they should use the phantom powered mini-xlr jacks instead.
Responses stating that there is a repeatable known issue where the audio cuts out when the gain is raised too high. (From 2019 but erupted in 2023)
I have tried all of these and are having the same problem with every “solution.”
Here is what I am experiencing:
When I received the camera I immediately charged a battery, put in a card, put on a lens and shot some test shots of my sons sawing wood for their pinewood derby cars. I checked that it was set to camera audio left and right for the inputs. I left the gain at the default. I just wanted to see what I would gety right out of the box.
I was no more than 4 feet away due to space limitations. They were talking at a normal speaking volume for 8 and 11 year old boys and, as I said, sawing wood. I also would talk to them over the sound of the sawing from right behind the handheld camera.
When I reviewed the footage at first I thought there was no sound at all but, with headphones on I can barely hear it. I then tried a few things in my house while my family was watching TV. I noticed that the meters never went above around -40dB. With headphones plugged into the camera, I could barely hear anything either. Yes, I was plugged into the headphone jack, not the microphone jack. With the gain turned all the way up (+6dB for the on camera setting) I get levels of around -30ish to -25dB.
I then tried a microphone in the 3.5mm jack - the RodeVideoMicro and set the inputs to 3.5mm - mic left and right. I got the same results. If I increase the gain to get the levels into the -6dB range I got significant background noise.
I have made several calls to Blackmagic customer service with various results:
The first person I talked to suggested I update to the latest firmware - no change
The second person kept insisting that there is no “normal” sound level and of course I would have to adjust input levels depending on the should level of my subject. Not addressing the issue that I could not hear my subject at all unless I “adjusted” my input levels all the way up.
Since all of this was just quick “living room” tests I decided to do more controlled tests.
I tested the following:
RodeVideoMicro - into 3.5mm
RodeVideoMic NTG (mic built in gain set at manufacturer rec’d 10)- into 3.5mm
Rode NTG-2 - into mini-xlr using a battery in the mic
Rode NTG-2 - into mini-xlr using +48v phantom power
Sennheiser MKE400 - into 3.5mm
Zoom H4n - using it only as a microphone into 3.5mm
Zoom H4n - using it as an audio interface between microphone and camera into 3.5mm
RodeVideoMic NTG into Zoom
Sennheiser e200 GW wireless into Zoom
I tested all of these mics in the following way:
1. Record at the default input level on the camera, noting what the audio meters were reading.
2. Record at whatever gain increase I needed to get the audio meters to land around -6dB (or as close as I could get. Some never got there.)
I then took those files into DaVinci Resolve. I raised the low audio level files to see what it would take to bring them up to around -6dB and hear what noise it added.
This is already an enormously long post so I’ll just sum up my findings. What I discovered is that ALL microphone levels regardless of input method were so low that their input levels needed to be raised to the maximum and for the on-board microphone, even that wasn’t enough.
The only setup that resulted in “normal” expected audio levels was when I either used the Zoom H4n as a microphone or routed the microphones through the Zoom H4n. My assumption is that this method utilizes the Zoom’s preamps rather than every other method using the Blackmagic preamps.
If that’s what people mean by saying that the onboard preamps are “notoriously bad” it seems a little out of spec from what any other camera manufacturer considers normal. I have never, in my years of using audio/video equipment run into this kind of audio issue.
I will render and post my tests if anyone is interested and, hopefully we can quantify the problems I and others are having and maybe we can finally get an apples-to-apples conversation.