GH3 GH3 audio features?

That mixpre-d looks nice. Would adding that into the chain produce AF100 (audio-wise) level results? If so, and the picture is improved over the AF100, this could be a reasonable option for an upgrade to A-cam.
 
traviswears said:
That MixPre-D looks nice. Would adding that into the chain produce AF100 (audio-wise) level results?
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Yes, if the GH3 camera audio circuitry has a low noise-floor.

Using a Sound Devices MixPre-D mixer to feed LINE level audio signal to my GH2 camera through a passive BeachTek DXA-2s XLR adapter, my GH2 shows a noise-floor of -63 dB, which is the SAME noise level as my HMC-150 when recording from a LINE level source.

I am hoping the GH3 has an even better noise-floor rating, but even -63 dB is very usable for me. In theory the GH3 should be better when recording in H.264 formats, as the audio is stored as LPCM data.
 
Fran Guidry said:
How exactly do I turn off the AGC in an unhacked GH2?
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You can't turn it off, but you can turn it down.

I find the AGC circuitry in the GH2 acts more like a limiter than the usual horrible AGC behavior, so even with it on ( and turned down as low as possible ) the recording sounds natural and does not clip.
 
Ok some news here. I found on the GH3 website references to audio level control and an image that looked a lot like the GH2's level control system (IE: before recording only.)

HOWEVER! I found reference to a silent operation mode (implying that you need it to be quiet because you are recording video) that says that "mic level adjustments" is one of the options that can be moved to the touch screen (as opposed to a dial, button, etc) for silent operation. Now, the only reason you would need silent operation would be while recording video, so this could be a breakthrough here, maybe.

"
The sound of the zoom or button operation may be recorded when taking videos. In Silent Operation mode, the zoom*, aperture, shutter speed, exposure compensation, ISO sensitivity and mic level adjustments are all touch-controlled."


​
Lets parse this sentence a bit. Because the sound of the zoom or button operation might be recorded while taking a video, here are the thing that can be placed as touch screen controls. Boom, audio level adjustment and, ISO (if we can change while shooting that's a big deal too!) are on there. So this implies that the camera may be able to change audio levels (and ISO!) while recording since why else would you need silent operation mode to work for these? This, combined with the images showing it does indeed have something somewhat akin to the GH2's audio modes, make me optimistic, but not for sure relieved.


​
 
TheDingo said:
Yes, if the GH3 camera audio circuitry has a low noise-floor.

Using a Sound Devices MixPre-D mixer to feed LINE level audio signal to my GH2 camera through a passive BeachTek DXA-2s XLR adapter, my GH2 shows a noise-floor of -63 dB, which is the SAME noise level as my HMC-150 when recording from a LINE level source.

I am hoping the GH3 has an even better noise-floor rating, but even -63 dB is very usable for me. In theory the GH3 should be better when recording in H.264 formats, as the audio is stored as LPCM data.
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Wait...does the Mixpre not have XLR ins? I was assuming it did. So you have to have a Mixpre-d AND a Beachtek adapter? Sigh...someone please come out with a simple and compact solution for this!
 
traviswears,

I saw TheDingo's post too and was also a little confused.

Dingo, why do you have to use the Beachtek?
 
traviswears said:
So you have to have a Mixpre-d AND a Beachtek adapter? Sigh...someone please come out with a simple and compact solution for this!
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MixPre-D Mixer : Because I want professional quality mic pre-amps and the ability to supply 48 volt phantom power to 2 XLR mics for 4+ hours using only rechargeable 2AA batteries

BeachTek DXA-2s : Because I want a professional quality passive XLR to 3.5mm stereo audio input solution for my GH2 camera

...As far as I know, there is nothing better than this combo in the DSLR audio world. Lots of cheaper solutions, but none as good.
 
DvxHerb said:
Are you using the BeachTek in lieu of a padded cable?
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Yes. The BeachTek adds mic/line switches, two pots to control signal level, a ground-lift switch to get rid of induction hum, and a stereo/mono switch. This unit snaps underneath my GH2 or the HS700 consumer cam that I use when filming 1-4 day medical symposiums.
 
Thanks for the explanation. I can appreciate striving for the highest quality.

I find that I need to simplify because I mess things up and get flustered if I have too many things to fiddle with. But if it was a significant difference in quality... I might try it out.
 
Has anyone seen the mics on the GH3? They're pretty obvious on the GH2, but I can't find them on any pics I've seen of the GH3.
 
DvxHerb said:
But if it was a significant difference in quality... I might try it out.
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For the BeachTek adapter I would look for a used DXA-2s model which I've seen selling for as low as $60 on eBay.

The SoundDevices MixPre-D mixer ( or the older MixPre model ) makes a huge difference in obtaining high quality low-noise audio, especially for the high powered headphone circuit which lets you hear smallest detail being recorded. It's expensive, but definitely worth every cent it costs.

If the MixPre is outside your budget, then I would look at the JuicedLink MIC level audio units, which are also a great value for the price. This would replace both the MixPre-D and the BeachTek units I am using, yet still provide you with very good quality sound in a compact unit. ( lots of models/features to choose from in the JuicedLink line )
 
I see 'em now. Thanks.

I wonder how they perform compared to the GH2, whose audio quality was more than sufficient for my event work (and offered even more stereo separation than the DVX did.)
 
TheDingo said:
Look for two tiny holes near the EVF on the back of the camera.
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I thought the mics were the 2 tiny holes on the front of the camera (maybe those aren't holes). I was just guessing by pictures. Didn't see anything on the back other than a speaker.

EDIT*** I was wrong. I didn't even notice the mics up there.
 
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