GH3 I'm actually pleased with the pre-amp's audio quality. Is this wrong?

[jbklynnyc]

The common adage has been (paraphrasing) "with external mics, keep your external preamps high so that you can use the lowest mic input setting in the camera and avoid its noisy internal preamps."

But in fact, I'm finding that the GH3 has pretty capable preamps, and I've been using the mic inputs at levels between 5-10 and the audio, all in all, has been very clean. I've done a lot of tests through the Juicedlink RM333 unit that I have, and I'm finding the cleanest all-around audio setting to be at about 11:00 on the JL and the mic levels on the GH3 set to 7. I ride the levels -/+2 on the Juicedlink and get acceptable audio so far for the event-type footage I've been shooting. I'm just using a Rode NTG3 and Sennheiser ME2. Gaining the Juicedlink high and keeping the camera mic input level low creates an unacceptably high level of noise.

So I'm wondering -- is the Juicedlink noisier than other comparable preamps? Am I missing something here, because the GH3 sounds pretty darn good to me.

 

[stoneinapond]

So I'm wondering -- is the Juicedlink noisier than other comparable preamps? Am I missing something here, because the GH3 sounds pretty darn good to me.

The Juicedlink products has quieter preamps than many other manufacturers. It's one of the company's strong points.

 

[Sam Mallery]

Gaining the Juicedlink high and keeping the camera mic input level low creates an unacceptably high level of noise.

Perhaps the Sensitivity and Output of your Sennheiser wireless system is turned up a bit high, so by cranking up the pre on your juicedLink, you're boosting up the noise of the necessarily hot wireless system. Have you tested just the NTG-3 alone?

 

[jbklynnyc]

Sam, that's a really good point. The NTG3 sounds pretty quiet overall. I'll dive further into the sensitivity and AF out settings on the G3. Thanks for suggesting that.

 

[TheDingo]

I'm finding that the GH3 has pretty capable preamps

It's not the GH3 preamps that are the problem, it's the AGC circuitry that kicks after anywhere from 5-13 seconds of silence, and will raise the noise-floor up to +20 dB.

Because of this, I strongly recommend using the lowest audio setting you can with your GH3. ( I've been standardizing on level 1, which has the least amount of AGC at +3 dB )

 

[jbklynnyc]

It's not the GH3 preamps that are the problem, it's the AGC circuitry that kicks after anywhere from 5-13 seconds of silence, and will raise the noise-floor up to +20 dB.

Because of this, I strongly recommend using the lowest audio setting you can with your GH3. ( I've been standardizing on level 1, which has the least amount of AGC at +3 dB )

Thanks. Excellent tip. Hadn't known this, but experiment tonight with muted audio going through the GH3 input at various levels, recording and then listening to the resulting files, and indeed I could hear the AGC kicking in.

 

[hotchkiss]

Question - So how many here feel comfortable with the GH3's audio quality...enough to use it for interviews? I'm not up for sinking the cash into a AF100 ( or equivalent) at the moment, but the prospect of going dual system sound for everyday corporate production makes me shiver. Especially so, operating without a sound man.
Is the GH3 a contender in this regard?

 

[jbklynnyc]

After experimentation (and thanks to the tips on this thread) I'd say I'm pretty confident with the GH3 audio quality.

I shot verité with a Rode VM Pro for a while and for my purposes it was fine. I then upgraded to phantom powered mics using a Juicedlink RM333 and I'm happier.

I'd say the key is the get a good mic preamp with physical mixing controls -- something like the RM333 or the Sound Devices MixPre-D. And if you have the budget, record a second set of the audio to a recorder capable of capturing audio at a higher bit rate than the GH3. The AF100, like the GH3, records uncompressed 48kHz/16 bit audio. Since you are shooting corporate video in presumably controlled situations, synching in post for interviews is not really a big deal these days, especially if you've recorded tracks to the camera as well.

People with more experience than me might say otherwise, but I've yet to record anything using the GH3's mic input that qualified as terrible or unusable. Which I know isn't saying much, but that was something that couldn't be said of many cameras in this form factor just a scant two years.

 

[TheDingo]

So how many here feel comfortable with the GH3's audio quality...enough to use it for interviews?

If you shoot with the GH3's 50 Mbits MOV video modes it will record audio uncompressed in the LPCM format, with a dynamic range of 66 dB, which is fine for interviews.

To get the best audio you can from your GH3 you need to feed it a strong -15 dB audio signal, which will require an external mic pre-amp ( JuicedLink RM222 ) or an external mixer ( Sound Devices MM-1 or MixPre-D ) or a good UHF system. ( Sennheiser G3 UHF system )

 

[hotchkiss]

To get the best audio you can from your GH3 you need to feed it a strong -15 dB audio signal, which will require an external mic pre-amp ( JuicedLink RM222 ) or an external mixer ( Sound Devices MM-1 or MixPre-D ) or a good UHF system. ( Sennheiser AG3 UHF system )

I'd be feeding it audio from a Lectrosincs system or Countryman & Sony hardwire lavs (and record to a Marrantz 661). I've shot dual system before, IMO it's still a major PITA regardless of the current ease of syncing in post . Compromises, compromises.

Ala "Back to the Future"

Here's to hoping for a AF200 at NAB.