Interpreting the Mixer Bar

solarblast1 wrote on 12/4/2008, 11:28 AM
OK, I'm looking at the Master Mixer. It's graduated from 6 to 54 units. I take it these are relative measures in Db. 6 Db denoting a doubling, or (-) halving. Apparently, this is the overall volume control for all audio, correct? I'm considering a simple scenario. One video and one audio track. If I apply audio effects (NRT), audio envelopes, and audio fade-ins, then I would hear the result of them, correct?

Apparently, the game is to make sure the entire track does not produce periods of orange-ness at the top of the bar. As the track is played, numbers appear at the top and bottom. What do they indicate? Max, min values? I see -2.5 and -5.4 at the top, and 0.4 and 0.4 at the bottom. What do they mean. I would have guessed 0.4 and 0.4 means the L & R tracks are above some value. If so, then I would think the orange indicator would be at the bottom. The 0.4s stay pretty constant across the small segment I'm looking at, 2 minutes, Comments?

Comments

newhope wrote on 12/4/2008, 4:01 PM
The measurements indicate decibels (dB) in the dBFS (dB Full Scale) range where 0dB is the maximum permitted signal level.
Ideally you adjust your levels so that they approach the maximum 0dB point but do not exceed it.
In broadcast systems you usually maintain a lower maximum of -10dB but if you are producing for domestic use or DVD then the 0dB point is perfectly acceptable as the maximum level.

As for the color indicator it is just a reference as the signal gets closer to the permitted maximum it changes to orange.

The numbers at the top indicate the maximum signal reached during replay and can be reset by clicking on them.

New Hope Media
solarblast1 wrote on 12/4/2008, 9:10 PM
Since the top is showing negative values, wouldn't that indicate a diminished sound? However, it seems it gets louder as the bar's height increases. It makes sense to color the bar orange as the bar height increases, and causes more distortion.

If I play with the slider, I can get positive values on both bop and bottom, and the same for negative. It seems these values do not relate to the scale in the middle.

Is what I'm hearing the sum of all effects from the sources I mentioned? I would think so.
newhope wrote on 12/4/2008, 11:23 PM
You are seeing negative values because the the maximum on the dBFS scale is 0 dBFS.
There fore signals below the maximum are indicated as -x dBFS.

If you exceed the maximum in Vegas you get an indication of the over shoot as a positive figure +x dBFS BUT that should be avoided at all costs as you are just sending the signal into distortion.

As mentioned before the numbers indicate the maximum level reached during any replay period. They 'hold' the maximum peak reading until they are reset so are only an indication of that momentary peak when reached. That is why they don't seem to relate to your movement of the slider. On the other hand the individual track faders (sliders) will indicate the volume level at which the fader is set from moment to moment in realtime on the track. It is here that you should be adjusting your levels NOT the master fader

Unlike analogue systems, where there is usually some leeway in over modulation, digital audio is very unforgiving when you reach the maximum.

On the master fader you are hearing the sum of all tracks. The preferred method of mixing is to adjust the levels on the individual tracks and leave the master fader at a set level. You can assign your track output to Busses (search for reference to Buss in the Help files) to give yourself the ability to control the level of a number of grouped tracks if you need. The Busses then feed the signal to the Master fader. Submixing on Buss faders IS a standard practice in mixing audio (which I've been doing professionally for over 30 years)

http://www.newhope.com.auNew Hope Media[/link]
solarblast1 wrote on 12/5/2008, 11:16 AM
Very good. Thanks.