Choosing a VU or PPM scale

To change the scale of the meter, choose Channel Meters from the Options menu, choose VU/PPM Scale, and then choose a setting from the submenu (you can also right-click the meter to set its options).

VU and PPM scales are most useful for displaying the average volume of the signal. The meter represents the RMS average level during playback, and their attack and decay are not as sensitive as the peak meter.

PPM scales are useful for monitoring peak levels. The meters use a fixed integration time (5 or 10 ms) that is sensitive to increases in volume, but the meters are less sensitive to decreases in volume than the VU scales, which produces less meter activity and decreased eyestrain.

Item

Description

 

Traditional VU

The traditional VU meter is displayed with a scale of –10 dB to +2 dB. 0 dB on the VU meter equals 4 dBu.

 

 

Extended VU

The extended VU meter is displayed with a scale of –30 dB to +8 dB. 0 dB on the VU meter equals 4 dBu.

 

 

Logarithmic VU

Displays the meters in a logarithmic scale (like the Sound Forge peak meters) instead of the linear scales traditionally

 

associated with VU meters.

 

 

UK PPM

The UK peak program meter (also known as a BBC meter) is a Type II meter and is displayed with a scale of 1 to 7,

 

which corresponds to a range of -12 to 12 dBu:

 

UK Marks

dBu

 

7

12

 

6

8

 

5

4

 

4

0

 

3

4

 

2

8

 

1

-12

 

 

EBU PPM

The EBU peak program meter is a Type II meter and is displayed with a scale of –12 to +12, which corresponds to -12

 

dBu to 12 dBu. 0 on the EBU PPM equals 0 dBu.

 

The EBU PPM and UK PPM respond identically to increases in volume, but the EBU PPM decays more slowly.

 

 

DIN PPM

The DIN peak program meter is a Type I meter and is displayed with a scale of –50 dB to +5 dB, which corresponds to ­

 

44 dBu to 11 dBu. 0 dB on the DIN PPM equals 6 dBu.

 

 

Nordic PPM

The Nordic peak program meter is a Type I meter and is displayed with a scale of –42 dB to +12 dB, which corresponds

 

to -42 dBu to 12 dBu. 0 dB on the Nordic PPM equals 0 dBu.

 

 

 

Adjusting the VU/PPM meters’ sensitivity

Unlike peak meters, which read instantaneous changes in your audio signal, the VU/PPM meters read a portion of the signal and calculate the average level. The size of the signal that the meters read is determined by the meters’ integration time.

To set the amount of data surrounding the cursor that will be used to calculate levels in the VU meters, specify a value in the VU meter integration time box on the Status tab of the Preferences dialog.

The PPM scales use a fixed integration time:

Scale

Integration time

UK PPM

10 ms

 

 

EBU PPM

10 ms

 

 

DIN PPM

5 ms

 

 

Nordic PPM

5 ms

 

 

LEARNING THE SOUND FORGE PRO WORKSPACE 47