GH2 - Monitoring audio while recording

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xocomil

Well-known member
I've seen a few threads discussing the possibility of listening to audio while recording on the GH2. The two possibilities raised were using adaptors through either the A/V out port or (less likely) through the mini-HDMI port (digital to analog being the issue).

Now that people have the GH2 in their hands, has anyone looked into a way to hear audio as it's being recorded?
 
I don't have my GH2 yet but I plan on using a calibrated juicedlink JL-DT454 I think it's the perfect companion for monitoring and since the Gh2 has audio meters on screen while recording I will have an added level of confidence.
 
Ram S.O.S said:
I don't have my GH2 yet but I plan on using a calibrated juicedlink JL-DT454 I think it's the perfect companion for monitoring and since the Gh2 has audio meters on screen while recording I will have an added level of confidence.
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Monitoring off a mixer instead of the recording device (in this case, the camera itself) only monitors the microphone & mic cables or wireless connection.

It doesn't tell you if the camera is actually recording usable sound. The connection between the mixer & camera is inherently unreliable (since it depends on tiny 2.5mm and/or 3.5mm plugs/adapters), so you can easily end up with a garbled/noisy recording, or no recording at all.

In other words, a disaster waiting to happen.

That's why real live monitoring from the recording device (the camera or an external recorder) is so important. It's the only way to know if the sound is getting recorded properly.

I don't have my GH2 yet, so I can't confirm if it features live audio monitoring (either through the A/V connector or HDMI), regrets. What little I've "heard" so far isn't promising.

So, to get the most reliable results, use an external recorder & sync in post either manually or use PluralEyes software.

Obligatory note: Such a shame, all because DSLRs don't include a $0.05 US headphone jack. Sigh. :-(
 
i don't have the answers either and can't test right now with my GH2, but I did plug my senheisser me66 directly into the GH2 to test. (With my GH1, I always used the H4n and pluraleyes.) I did watch the levels in the GH2 and the audio recorded in the camera was truly excellent. For interviews, this will now be the way to go for me although I probably will still back up with the H4n - but I won't have to do the extra step of syncing.
 
Great to hear Larry. Having levels is a step in the right direction.

I'd still love to know if someone's tried to use an adaptor to plug in some headphones while recording.

One of the reasons the camera appeals to me is its stealth and simplicity ...
 
Back in September a user named AKED confirmed that the GH2 is supposed to pass audio through the HDMI out during recording:

http://www.dvxuser.com/V6/showthread.php?223562-What-do-you-want-to-know-about-the-new-GH2

So in theory, what would be needed is a small, battery powered device that could accept an HDMI input and provide a headphone output.

After a little bit of searching I found this thing:
http://www.amazon.com/HDMI-RCA-Component-AV-Converter/dp/B002WBOQPU

It lacks battery power and a headphone output, but it gave me a little hope.

I'm really curious if the audio through HDMI thing works, and if there's a better HDMI gadget out there for monitoring with headphones.
 
With my GH2 connected to a 1080p monitor via HDMI and with the GH2 HDMI output set to auto, 1080i, 720p, 480p, there is NO audio output to the monitor in live or record mode. It is there only in playback. That rules out any audio monitoring via HDMI.

I also noticed the ETC function does not work when the HDMI cable is plugged in and the ETC only works when there is no HDMI cable plugged in, this is regardless of stock 14-140 or any other lens I used.

Both are a let down!
 
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mickee13 said:
Wow, that is a real bummer. Are you able to test the a/v out for audio?
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Composite audio is NOT available in live or record mode as well - only in playback.
Composite video is only displayed in live view and goes blank when in record mode just like a GH1.
There is no composite video output when the HDMI is connected.
 
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Peter J. DeCrescenzo said:
Monitoring off a mixer instead of the recording device (in this case, the camera itself) only monitors the microphone & mic cables or wireless connection.

It doesn't tell you if the camera is actually recording usable sound. The connection between the mixer & camera is inherently unreliable (since it depends on tiny 2.5mm and/or 3.5mm plugs/adapters), so you can easily end up with a garbled/noisy recording, or no recording at all.

In other words, a disaster waiting to happen.

That's why real live monitoring from the recording device (the camera or an external recorder) is so important. It's the only way to know if the sound is getting recorded properly.

I don't have my GH2 yet, so I can't confirm if it features live audio monitoring (either through the A/V connector or HDMI), regrets. What little I've "heard" so far isn't promising.

So, to get the most reliable results, use an external recorder & sync in post either manually or use PluralEyes software.

Obligatory note: Such a shame, all because DSLRs don't include a $0.05 US headphone jack. Sigh. :-(
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I'm thinking that even when you're monitoring off of a separate sound recorder you're still only hearing what is being fed into it & not actually what it records. Unless of course you hear it delayed from the live sound. But I suspect most of these cheap recorders are just giving you input monitoring. So it's probably just as safe as monitoring the input to the camera as long as you're watching levels.
 
KarlSutton said:
But I suspect most of these cheap recorders are just giving you input monitoring. So it's probably just as safe as monitoring the input to the camera as long as you're watching levels.
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Most portable digital recorders provide "confidence monitoring," meaning that you're listening to the sound that's being recorded.

Looking at audio meters and listening to audio are two completely different things. For example, if you're using a wireless lav and the mic is clipping at the input setting on the transmitter - yet the output of the receiver and the input on the recording device both have healthy gain settings - the meters will look perfect, but the audio will be distorted garbage.
 
KarlSutton said:
I'm thinking that even when you're monitoring off of a separate sound recorder you're still only hearing what is being fed into it & not actually what it records. Unless of course you hear it delayed from the live sound. But I suspect most of these cheap recorders are just giving you input monitoring. So it's probably just as safe as monitoring the input to the camera as long as you're watching levels.
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No, it's not, for the reason I stated in my post.

The cable, plugs & adapters connecting the sound source to the camera are notoriously unreliable. They often produce crackles & noise when they move/rotate, are easily pulled loose or pulled out of the mic input socket -- including when they're only slightly disconnected -- causing the sound to cut in & out, hum, buzz, etc.

Level meters on the camera only give you one of many, many pieces of info you need to know when monitoring audio. It's far more important to listen to the sound than look at meters, indicators, etc.

It's OK to record audio in-camera if the camera's automatic level control (or auto limiting or whatever it's doing) is acceptable, or if it's relatively low-quality pre-amps are acceptable, or if the camera's relatively low-fi sound recording format is acceptable, and it's even acceptable if the mic cable falls out, buzzes, crackles, etc. ----- if ----- the recording isn't important, or if it's OK to go again and shoot another take when something inevitably goes wrong. It's all good if this is OK.

But otherwise, use an external sound recorder, too, and _listen_ to the live audio on good headphones while it's being recorded.

Aside to Sam: Hey, a shout-out to Hoboken! I'm originally from Ho-Ho-Kus! :-)
 
rigs said:
With my GH2 connected to a 1080p monitor via HDMI and with the GH2 HDMI output set to auto, 1080i, 720p, 480p, there is NO audio output to the monitor in live or record mode. It is there only in playback. That rules out any audio monitoring via HDMI.
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That really sucks. I should have known that you can't put much faith in the features a product rep tells someone about days after a new camera is announced. Still though, it's a drag that we were led astray.

rigs said:
Composite audio is NOT available in live or record mode as well - only in playback.
Composite video is only displayed in live view and goes blank when in record mode just like a GH1.
There is no composite video output when the HDMI is connected.
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That's too bad. It would be great if the composite audio stayed alive during recording. Then we could pick up a simple battery powered box like this ART MyMonitor:

http://www.bhphotovideo.com/c/produ...ITOR_MYMONITOR_Personal_Portable_Monitor.html

Is the composite output something that can be messed with in a firmware hack? That would be a great addition.

Peter J. DeCrescenzo said:
Aside to Sam: Hey, a shout-out to Hoboken! I'm originally from Ho-Ho-Kus! :-)
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That's awesome. I love the name of that town. One of my best friends has lived in Portland for the past 16 years. I've been there so many times to visit that I feel like I'm originally from there. :happy:

The GH2 is still my top pick for what camera body to get, but I'm still bummed that the audio monitoring feature was a lie.
 
Sam Mallery said:
... The GH2 is still my top pick for what camera body to get, but I'm still bummed that the audio monitoring feature was a lie.
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IMHO, the GH1's & GH2's lack of a live audio monitoring output (e.g.: a headphone jack) is idiotic, but that's just me.

Um, wait ... :-)

Rant on: (Please avert your eyes if you'd rather not read this ...):

Having used thousands of electronic gadgets over the decades, I'm convinced Panasonic could provide basic live audio monitoring on these cams essentially for free. To the best of my knowledge, designing-in live audio monitoring during recording is trivially easy to do. It's certainly easier & cheaper than supporting live HDMI during recording, and the GH2 has that. But for Panasonic to ignore requests for live audio monitoring during recording for more than a year now is borderline customer-hostile. I completely don't get it.

Yep, yep, I know, I know: "The GH2 is a stills camera with a nice video feature." My *ss it is. :-)

In some ways the GH2 is more a video camera than a stills camera. To not include a headphone jack, or to not enable live audio via the A/V connector or HDMI port is inexcusable. It would only cost them mere pennies to implement. And a headphone jack would cost them nothing in additional end user support costs since you don't have to explain to 99.9% of consumers what a headphone jack is for!

And yep, yep: Having to spend an additional ~$4K US to get a headphone jack on an AF100 is a bit of a stretch, if all you wanted was a video-capable cam with a biggish sensor & live audio monitoring. Let's see, $4K vs. $0.05 ... hmmm. Jerks. :-)

Of course, I think Sony sells such a solution (kinda) for around $2K (NEX-VG10).

Rant off. :-)

Anyway, I'm still looking forward to my GH2 arriving soon.

Have a nice day!
 
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Sam Mallery said:
Most portable digital recorders provide "confidence monitoring," meaning that you're listening to the sound that's being recorded.

Looking at audio meters and listening to audio are two completely different things. For example, if you're using a wireless lav and the mic is clipping at the input setting on the transmitter - yet the output of the receiver and the input on the recording device both have healthy gain settings - the meters will look perfect, but the audio will be distorted garbage.
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I dont think most portable digital recorders outputs whats being recorded to headphone. e.g. SD USBPre2 outputs to headphone before analog-to-digital conversion. i.e. analog to analog to headphone, not analog to digital to analog to headphone.

I have no problem with that as long as whats being recorded is close to whats being output to headphone.
 
A little off topic, but has anyone notices that the first 9 frames of audio on each GH1 clip are not recorded. Audio, on all my GH1 clips (recorded in camera) start on frame 10.

Back on topic - I'm with you Peter. It's ridiculous they didn't include a audio jack.
 
Peter J. DeCrescenzo said:
Monitoring off a mixer instead of the recording device (in this case, the camera itself) only monitors the microphone & mic cables or wireless connection.

It doesn't tell you if the camera is actually recording usable sound. The connection between the mixer & camera is inherently unreliable (since it depends on tiny 2.5mm and/or 3.5mm plugs/adapters), so you can easily end up with a garbled/noisy recording, or no recording at all. In other words, a disaster waiting to happen.
Click to expand...

It's not as doom and gloom as you might think...

For field recording I use a Sound Devices MixPre to power my mics and feed LINE level audio to the camera and recorder. With this set-up you can definitely monitor the audio that the mixer is producing ( the headphone amp on the MixPre is far better/louder than any consumer camera/recorder I've used to date ), and if you properly calibrate your camera with the mixer's 1 kHz test tone, you will know that your camera is not distorting.

By keeping an eye on the GH-2's audio level display, you can tell if you are getting signal from the mixer when sound is happening.

So you can monitor with the excellent mixer head-phone amp, you can calibrate your camera's sound level with the mixer's test-tone, and as long as you are seeing active audio level indicators on the camera's display then you can be pretty sure you are getting good sound. ( as a back-up you can connect a small digital recorder to the mixer through the tape-out connection, so that you can simultaneously record on both the camera and the recorder at the same time )

I did a quick audio test tonight comparing my GH-2 against my Canon 60D, and the GH-2 definitely came out on top. Here's what I did...

1- Connected the Sound Devices MixPre to a BeachTek DXA-2 passive XLR adapter ( I've been using this adapter for years and it is truly great, extremely quiet with no alteration of the audio it's passing through )

2- Used a stereo 3.5mm to 2.5mm mini-plug adapter to connect the BeachTek to the GH-2
( this adapter cost me $1 at a dollar-store, and claims to be gold-plated )

3- Powered up the MixPre and switched on the 1 kHz test-tone

4- Used the menu to set the GH-2 MIC level to it's lowest setting, which was NOT LOW ENOUGH to set a proper -12 dB recording level, so I ended up using the level control on the BeachTek to lower the level even further ( quite a bit actually ) until the GH-2 recording level was showing no red-bars on the meter. I correctly assumed that this was -12 dB.

5- Finally recorded 10 seconds of the test-tone at the 24P 24 Mbps setting, then switched off the test-tone and continued to record the noise-floor of the camera.

6- Brought the MTS file I just created in to Sony Vegas Pro 10, and exported the audio track to Sony Sound Forge 9 so that I could measure the noise floor.

When I checked the GH-2 audio recording the test-tone was reading at -12 dB, and the noise floor when the test-tone was shut off was reading at -63 dB, which is comparable to the audio that my HMC-150 camera records, not fantastic but good enough for general production.

I repeated the test with the Canon 60D, and the Canon allowed me to drop the MIC level low enough that I did not have to use the level control on the BeachTek ( it was set to maximum ), but when I checked the results with Sound Forge the noise floor was reading -53 dB, or 10 dB NOISIER than the GH-2.

The best consumer camera that I've tested to date is the Panasonic HS700 consumer camcorder, which tested with a noise floor of -82 dB. Amazingly quiet for a consumer cam.

This type of test is a bit of a theoretical test, as it does not take in to account self-noise from the mic or room-noise from the environment where you are recording, but it does give you an idea of how a camera/recorder could perform under ideal conditions.

I would have no qualms recording audio in to the GH-2 with the set-up that I used. At some point soon I will have to shoot something with nice sound and see how the GH-2 compares to a good digital recorder.
 
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