Blackmagic Forum

Robert from JuicedLink made a new video about the changes in the new firmware.
He found a new gain sweet spot, different frequency response, and what it all means to your audio workflow.

http://juicedlink.com/blog/2013/04/blac ... dio-tests/

Thanks Frank.

Thank goodness for the forums otherwise it would have been a long time before i discovered these changes (no thanks to the changelog )

Cheers Frank!

That's really interesting - thanks for sharing Frank!

I'm going to have to do some more testing. I wonder if the "sweet spot" of 80% as shown in the video only applies to Mic Level - as opposed to Line Level? Originally I was thinking that 100% Line Level was 0dB Gain/Attenuation - but maybe not?

Why, oh, why can't Blackmagic just release some information telling us what they're doing behind the scenes? All they would need to do is add a couple of extra lines to the manual or release notes!

And curious why BMD changed the frequency response - it's worse, now, apparently.

My GUESS is that when they fixed the DC-offset, they didn't adjust the processing algorithms to suit.

After watching Robert's video however, it seems with a bit of post-processing, it's not really an issue at all - just more of an annoyance.

I'm not sure what's worse - having to EQ all your audio, or having to repair the DC-offset.

Given that the DC-offset messes with your meters - I'd say the firmware update is still very much worthwhile.

Maarten wrote:And curious why BMD changed the frequency response - it's worse, now, apparently.

I don't know the frequency response of the internal fan but that may be what they are trying to eliminate. Tried too hard obviously. Fan noise may be virtually eliminated in your own audio software by judiciously applying lower EQ for very low frequencies or using the sledgehammer of a filter that eliminates the lowest frequencies. Fine for voice since we don't talk at the lowest frequencies. Not good for music.

Rick Lang
Sent from my iPad using Tapatalk HD

I'd be careful about boosting your low end that much in post. Its fine for the most part to do on dialogue recorded in a controlled environment, but doing that to anything shot outside would probably render the audio unusable.

I guess it really depends on whether you're recording using Line Level or Mic Level - as looking at the frequency response plot spreadsheet, line level seems to be a lot more smooth and less forceful.

Having said that... I really need to do some tests first hand.

I was astonished at the low end rolloff. Typical voices sound better with somewhat fatter, rounder low end, even female voices. Robert's voice is not an ideal test, but I am grateful for his test.

I am sticking with v1.2 for now. That freq response curve is the one I want. I will continue to use Robert's trick to use his preamp to supply sound using about a 25% volume setting on the BMCC preamps. I will now just set it to Line level to avoid changes.

BMD is not doing so well in the audio department. Red was worse back in the day, but I have to think, if BMD had someone who was even somewhat in Robert's league, we would not be getting this much poor engineering of the audio capture.