Bose FREESPACE 4400 User Manual

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When a page signal is triggered, the music signal is ramped 
down according to the ducking time. The ducking time is preset 
at 20 ms for Auto detection and 0 ms for PTT triggering. The 
music level is reduced by the ducking depth which can be 
adjusted using the ducking depth control. Ducking depth is 
adjustable from 0 to –40 dB. Once a page is completed and the 
Hold Time has elapsed, the music volume is ramped up accord-
ing to the ducking release time, which is adjustable from 0 to 5 
seconds in 0.5-second increments.

The Zone EQ control panel provides a three-band equalizer for 
adjusting the sound quality of the zone. 

Click and drag each slider to the level you want. The scale on the 
left side of the panel is expressed in dB.

The center frequency and shape of each EQ band is fixed and 
can be adjusted by ±6 dB.

• The low-frequency EQ (LF-EQ) is a low-pass shelf EQ with a 

corner frequency of 125 Hz and a roll-off of 6 dB per octave.

• The mid-frequency EQ (MF-EQ) has a center frequency of 

 

1.6 kHz and a Q of 1.

• The high-frequency EQ (HF-EQ) is a high-pass shelf EQ with a 

corner frequency of 8 kHz and a roll-off of 6 dB per octave 
below this point.

Music 
signal

Ducking depth

0 to –40dB

Page 
signal

Ducking Time:

Fixed at 20 ms for Auto Detection,

0 ms for PTT Detection.

Release Time

0 to 5 secs

Hold Time

0 to 5 secs

0 dB

0 dB

0 dB

MF-EQ

LF-EQ

HF-EQ

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