I don't see how it can be both, as they are two different things. The Limiter will only reduce the level, AGC will both raise and lower the level. It there's any raising of the level at all, it's not a Limiter, and shouldn't be called such.
GH4 audio bug discovered
- Thread starter tacotim
- Start date
I don't see how it can be both, as they are two different things. The Limiter will only reduce the level, AGC will both raise and lower the level. It there's any raising of the level at all, it's not a Limiter, and shouldn't be called such.
What about the other settings?
Ed Kishel
Veteran
I figured as much, no harm no foul- I can be a smarty pants myself (i.e. the hello kitty crack from earlier).
TheDingo- no more testing for me, sorry but I've grown a bit tired of noise floors this, negative dBs that.
Ed Kishel
Veteran
Well, with my camera that's were the real issue was. Listen to the samples I posted on page 10- at its default setting (0dB) it was quite obvious and unusable IMO.
By both, I mean that they've got both an AGC circuit and a Limiter that are controlled by ONE camera setting, instead of giving us separate controls to enable/disable each of these by themselves. This is better than the GH2/GH3 cameras where we had no way of turning anything off.
I have yet to find any situation where the AGC circuit is useful to me, and wish that Panasonic would just remove it from the camera completely.
This is exactly my point. People who haven't purchased the GH4 yet should know that it's a non-issue for 99.988% of GH4 users. And I'm being literal, as only one person out of 8,127 (thread views) so far has returned their GH4 due to this issue.
Harry Pallenberg
Well-known member
I tested mine and I sure have the bug, you can hear the 'chainsaw' like noise even on the internal mic if you boost db up...
But (in all seriousness) like the 2 people above I consider it a non issue even when doing sit down interviews in a small quiet room with a lav the
noise floor of the mic / room tone covers the buzz.
But (in all seriousness) like the 2 people above I consider it a non issue even when doing sit down interviews in a small quiet room with a lav the
noise floor of the mic / room tone covers the buzz.
I tried using the noise-gate solution I suggested previously, and it completely eliminated the GH4 Audio "Buzz" bug.
I am 100 percent convinced that what people are complaining about is the GH4's modulated noise-floor, which is a motor-like buzz sound.
With the GH2 and GH3 cameras the noise-floor sounded like random "white" noise.
Using a -62.5 dB noise-gate filter in Sony Sound Forge I was able to completely remove the GH4 noise-floor buzz sound, so that you could then boost your GH4 audio as loud as you like and you will not hear ANY buzz sound.
The -62.5 dB noise-gate filter is ONLY for GH4 audio recorded at the -12 dB camera audio setting, so if you use other GH4 camera settings you will need to determine what the GH4 noise-floor is for that setting, and then apply a noise-gate filter that will eliminate the noise-floor.
Here's a very quick YouTube demo I threw together to illustrate what is going on...
I am 100 percent convinced that what people are complaining about is the GH4's modulated noise-floor, which is a motor-like buzz sound.
With the GH2 and GH3 cameras the noise-floor sounded like random "white" noise.
Using a -62.5 dB noise-gate filter in Sony Sound Forge I was able to completely remove the GH4 noise-floor buzz sound, so that you could then boost your GH4 audio as loud as you like and you will not hear ANY buzz sound.
The -62.5 dB noise-gate filter is ONLY for GH4 audio recorded at the -12 dB camera audio setting, so if you use other GH4 camera settings you will need to determine what the GH4 noise-floor is for that setting, and then apply a noise-gate filter that will eliminate the noise-floor.
Here's a very quick YouTube demo I threw together to illustrate what is going on...
I think a lot of people confusing who complains about what. Some here complain about the buzz while monitoring (like me, and I think at the moment that's the major issue to focus on), some complain about it being recorded and others about both. I actually don't care about the buzz being recorded because I agree with TheDingo, the buzz is hidden so low in the noise floor that only by sky rocketing the gain will somewhat make it apparent. But, the buzz while monitoring/recording from the camera is just utterly annoying and creates painful usability.
The fact that panasonic will do nothing is even more frustrating (I actually feel that new batches won't have that issue because panasonic will quietly fix it with no solution for people who experience this bug now).
The fact that panasonic will do nothing is even more frustrating (I actually feel that new batches won't have that issue because panasonic will quietly fix it with no solution for people who experience this bug now).
I strongly suspect the buzz while monitoring is a result of the massive 20-25 dB increase in mic gain that Panasonic gave the GH4, which brought out the flaws of their in camera audio shielding. I would rather have the gain increase so I can actually get a proper recording with a standard -50 dB mic signal, compared to the GH3 where you needed to boost any mic level signal by 25+ dB to get a good recording.
The stupid solution is for Panasonic to change the firmware and put the mic input sensitivity back to the poor GH3 levels, which would likely make the GH4 buzzing noise-floor go away. This is something that I really don't want.
For myself, I've been using a Fostex DC-R302 mixer/recorder with my GHx cameras, which has it's own headphone output, so I would use that instead of the GH4 if the buzzing was driving me nuts. ( the Fostex also gives me a second 24-bit recording with a -80 dB noise-floor, which I prefer to use if I have time in post )
Sol M.
Veteran
Off-topic, but what's the battery life on the R302 (phantom power on/off)? How much does it extend out beyond the sides of the GH3/GH4?
I haven't done a battery run-down test yet, but I will make sure I do this on Sunday, and post my results. Internally it takes 4 AA batteries or can run from an external battery or AC power.
Here is how I currently rig the Fostex with my GH3
This might not be the normal way to rig this unit, but it's what I prefer when shooting.
For the GH3 I run the Fostex tape-out directly into it, and plan on running the Fostex mic-out into the GH4.
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Ed Jeffersen
Active member
My MixPreD seems to work well with the camera at -12, but there are times I want to travel light and simple. That means a hot shoe mounted mic for nat sound.
I'm going to order the Panasonic mic, and sell my two Rode mics.
I'm going to order the Panasonic mic, and sell my two Rode mics.
Sol M.
Veteran
Before you sell your Rode mics, I'd definitely make sure the issue is resolved using Panasonic's mic as I believe their "solution" to be a red herring. The buzz is present without any mic plugged in, so their claim that the buzz is caused by mics with a TRS jack as opposed to a TRRS jack is not very compelling.
+1
Yes, the "buzz" seems like an audio shielding weakness of the current GH4 design, so there is a chance that the Panasonic mic won't change things.
Ed Jeffersen
Active member
So it is only Panasonic saying their mic works without noise? Anybody here done a comparison Rodes vs Panasonic?
The main problem has to do with levels not matching. Rode VMP at +20dB position clips the GH4 at -12dB. If I set the VMP to 0, and raise the GH4 level, the noise floor is too high. A possible solution would be a 10dB pad between the VMP and the GH4. Of course it all depends on the source. A Panasonic firmware update that extended the attenuation to -24dB would solve my problem at least.
Even so, it's silly to have a shotgun AND a stereo mic in the bag if the Panasonic does both.
If I don't like it - back it goes. Amazon takes returns!
