Index > Meters

Meters

The following descriptions are about the sound meters or indicators on the main window.

NOISE GATE LEVEL

The green lamps indicate the noise gate status of each band.

This feature can be used if the sound source contains some hiss noise or white noise such as an analog music cassette tape. When using digital sound sources, disable this feature.

The gate level can be adjusted using the Gate Threshold level of each band. The adjustment should be done like:

1) Play the sound portion that contains only hiss noise such as the portion between songs.
2) Set the Gate Threshold level of each band to the level just before the green lamps get lighting.

More than 90% open ( higher than -1dB ) : Lamp FULL lighting
50% ~ 90% open ( -6dB ~ -1dB ): Lamp 2/3 lighting
25% ~ 50% open ( -12dB ~ -6dB ): Lamp 1/3 lighting
Noise gate less than 25% open (lower than -12dB ): Lamp OFF

The noise gate feature is enabled when the NOISE GATE button is ON. When the button is OFF, the noise gate feature will be disabled and all gates fully get open.

The Gate Threshold value is not save to presets and parameter files because this should be adjusted depending on the input sources.

STEREO ENHANCE LEVEL

This is the peak level meters for the stereo enhancing function. This shows the (L-R) signal level mixed to the main audio line. This scale is linear and its unit is not "dB". The maximum level "100%" is equivalent to 16bit digital audio range "+32767".

INPUT LEVEL

This is the input peak level meters. This scale is linear and its unit is not "dB". The maximum level "100%" is equivalent to 16bit digital audio range "+32767".

AGC: Limiting ratio of input sound level

This shows the limiting ratio (dB) of 2 band AGCs (Automatic Gain Controllers) just after the input. The recording level of every song is deferent. This AGC will uniform the sound level sent to the multiband limiter in order to get the best effect. The level bar shows the limiting ratio.This AGC has crossover at 200Hz and the low and high bands are processed separately.

Pre-emphasis Limiting ratio and HF level

These meters are for the pre-emphasis adjustment. FabulousMP3 supports 50us / 75us pre-emphasis for FM broadcast. Over 2kHz is boosted with 6db/oct slope for 75us pre-emphasis, and over 3kHz is boosted with 6db/oct slope for 50us pre-emphasis. In order to avoid clipping of high frequency band by pre-emphasis booster, FabulousMP3 has an HF limiter. These meters shows the HF limiting ratio(dB) and HF signal level (%).

Multi Band Limiter(dB): Limiting ratio of each band

This shows the limiting ratio (dB) of each frequency band separately. The level bar shows the limiting ratio and a scale means -1dB. The red lamps under the meter are clipping indicators for each band. The clipper is located after the multiband limiter. It cuts the unnecessary peaks and suppress the signal to a certain level. This clipper is, so-called, "Soft knee" clipper and the distortion sound can be soft like a vacuum tube amplifier.

OUTPUT LEVEL

This is the output peak level meters. This scale is linear and its unit is not "dB". The maximum level "100%" is equivalent to 16bit digital audio range "+32767". The red clipping indicator lights when the final output just before the de-emphasis filter would overshot -0.2dB.