Audio Input Levels at DVinfo.net

Dan Brazda · October 26th, 2007, 03:17 PM

So my understanding is that the demarkation between the open LED squares and the filled LED squares in the viewfinder audio monitoring display is at -20db and the top square is 0 db. In practice, this doesn't seem to even be in the ballpark at least when using rear line level inputs on Ch 1&2. I monitored an entire concert recording to keep the peaks at or below 0 db and averaging about -12. When I imported the footage and played it back in FCP it was consistantly about 8 db lower than what I was watching. Ideas?

Andy Mees · October 26th, 2007, 08:21 PM

Dan

I tested this, after a fashion, once before:
I used an F350's internal signal generator to record a clip of bars and tone with a line up level of -20db.
When played it back, the levels displayed correctly at -20db in the viewfinder audio monitoring display
I then imported the clip via FAM to FCP.
When the imported clip and played it back in FCP's viewer or timeline the audio levels measured exactly at -20db just as they should.
Try the exact same test as above with your own kit, and see if your results match. If so then it would suggest that what you're seeing is an inconsitent metering issue. When you play the footage back in camera do the levels displayed match what you saw when monitoring during record, or are they consistent with the levels as measured in FCP?

Cheers
Andy

Dan Brazda · October 26th, 2007, 08:36 PM

Thanks Andy. I'll do the same test and ost the results.

October 26th, 2007, 03:17 PM	#1
Dan Brazda Regular Crew Join Date: Oct 2006 Location: Richmond, VA Posts: 165	Audio Input Levels So my understanding is that the demarkation between the open LED squares and the filled LED squares in the viewfinder audio monitoring display is at -20db and the top square is 0 db. In practice, this doesn't seem to even be in the ballpark at least when using rear line level inputs on Ch 1&2. I monitored an entire concert recording to keep the peaks at or below 0 db and averaging about -12. When I imported the footage and played it back in FCP it was consistantly about 8 db lower than what I was watching. Ideas?

October 26th, 2007, 08:21 PM	#2
Andy Mees Major Player Join Date: Mar 2006 Location: Kuala Lumpur, Malaysia Posts: 645	Dan I tested this, after a fashion, once before: I used an F350's internal signal generator to record a clip of bars and tone with a line up level of -20db. When played it back, the levels displayed correctly at -20db in the viewfinder audio monitoring display I then imported the clip via FAM to FCP. When the imported clip and played it back in FCP's viewer or timeline the audio levels measured exactly at -20db just as they should. Try the exact same test as above with your own kit, and see if your results match. If so then it would suggest that what you're seeing is an inconsitent metering issue. When you play the footage back in camera do the levels displayed match what you saw when monitoring during record, or are they consistent with the levels as measured in FCP? Cheers Andy

October 26th, 2007, 08:36 PM	#3
Dan Brazda Regular Crew Join Date: Oct 2006 Location: Richmond, VA Posts: 165	Thanks Andy. I'll do the same test and ost the results.