Working on Surround Sound

Question 1

Explain level calibration.

Answer 1

You will need an SPL meter set to C weighting with a slow response setting, you will then play back pink noise at -20dBFS out of each speaker and measure it while tweaking the speaker output level.

The SPL meter needs to be measuring from the listening position in order to correctly balance the surround sound setup.

Calibrate each of the surround speakers to same level, unless mixing to a “straight to film” mix on a large mix stage. If this is the case, it is customary to have your ‘Ls’ and ‘Rs’ surround speakers -3dB SPL lower.

For both soundtrack mix production and the movie theater calibration, the LFE channel, is calibrated 10 dB SPL higher than the surround speakers.

Because of this +10 dB offset, the LFE channel can achieve a balanced output of bass as compared with the total output of bass from all the surround speakers (in other words it can single handedly compete with the 5 surround channels in terms of level).

Question 1

Explain level calibration.

Answer 1

You will need an SPL meter set to C weighting with a slow response setting, you will then play back pink noise at -20dBFS out of each speaker and measure it while tweaking the speaker output level.

The SPL meter needs to be measuring from the listening position in order to correctly balance the surround sound setup.

Calibrate each of the surround speakers to same level, unless mixing to a “straight to film” mix on a large mix stage. If this is the case, it is customary to have your ‘Ls’ and ‘Rs’ surround speakers -3dB SPL lower.

For both soundtrack mix production and the movie theater calibration, the LFE channel, is calibrated 10 dB SPL higher than the surround speakers.

Because of this +10 dB offset, the LFE channel can achieve a balanced output of bass as compared with the total output of bass from all the surround speakers (in other words it can single handedly compete with the 5 surround channels in terms of level).

Question 2

What is the problem with summing both your left and right channel of a stereo ambience?

Answer 2

It is that although you have signal coming from all surround speakers, the waveforms are all completely correlated.

Question 3

How do you get an ambiance sounding very special while coming out of all your surround speakers?

Answer 3

You need to de-correlate your

ambience stems.

Question 4

What plugin could you use to de-correlate your

ambience stems?

Answer 4

A stereo to 5.1 de-correlation plugin like the Waves S360 Imager.

Question 5

How do you enable glide automation?

Answer 5

1. Bring up the automation window with CMND + 4 on the numpad.
2. Enable only your pan automation.
3. Make a selection on the track timeline to set some automation break points.
4. Write the break point by selecting the toolbar’s Edit/Automation/ Write to All Enabled.
5. Nudge to the beginning of the pan movement, set the pan position and “Write to All Enabled” again.
6. Nudge to the end of the intended pan movement, set the end pan position and select “Glide to All Enabled” under the same Edit/Automation toolbar location.

Question 5

How do you enable glide automation?

Answer 5

1. Bring up the automation window with CMND + 4 on the numpad.
2. Enable only your pan automation.
3. Make a selection on the track timeline to set some automation break points.
4. Write the break point by selecting the toolbar’s Edit/Automation/ Write to All Enabled.
5. Nudge to the beginning of the pan movement, set the pan position and “Write to All Enabled” again.
6. Nudge to the end of the intended pan movement, set the end pan position and select “Glide to All Enabled” under the same Edit/Automation toolbar location.

Question 6

What is Down Mixing?

Answer 6

Downmixing is the concept of folding down your 5.1 mixes into less channels.