Klein + Hummel
O 810 / O 870 Operating Manual Page 11 of 96 Version 01
The LFE Mode
LFE ModeLFE Mode
LFE Mode switch has four settings (the default is LFE → SUB + L/R (>80)) designed to process the LFE
channel in different ways for different system configurations and source equipment. The LFE channel must be
applied to the dedicated LFE input channel for this processing to work (“LFE” on the analog input card, or input 2,
subframe B on the digital input card). Reproduction of the LFE channel is unaffected by the setting of the bass
management switches. The modes and their use are:
1.
1.1.
1.
LFE
LFE LFE
LFE →
→→
→ SUB + L/R (>80)
SUB + L/R (>80) SUB + L/R (>80)
SUB + L/R (>80)
Up to 80 Hz, the LFE channel is reproduced by the subwoofer. Above 80 Hz, the LFE channel is re-routed to
the left and right outputs. A 6 dB electrical attenuation is applied to compensate for a 6 dB acoustical gain
seen when reproducing one signal using two loudspeakers. This mode works with all formats and is
consistent with the standard downmix coefficients seen in consumer decoders. Additionally, this mode is
useful for detecting higher frequency signals (up to the upper cut-off frequency of the left/right
loudspeakers) in the LFE channel that should otherwise be avoided.
2.
2.2.
2.
LFE
LFE LFE
LFE →
→→
→ SUB ONLY (<80)
SUB ONLY (<80) SUB ONLY (<80)
SUB ONLY (<80)
The LFE channel is reproduced up to 80 Hz in the subwoofer only. This comes from a recommendation by
Dolby and THX to “pre-filter” the LFE channel and is used to simulate consumer decoders that do not
reproduce the upper part of the LFE bandwidth.
3.
3.3.
3.
LFE
LFE LFE
LFE →
→→
→ SUB ONLY (<120)
SUB ONLY (<120) SUB ONLY (<120)
SUB ONLY (<120)
The LFE channel is reproduced up to 120 Hz in the subwoofer only. This is the norm for the movie industry.
4.
4.4.
4.
LFE
LFE LFE
LFE →
→→
→ SUB ONLY (WIDE)
SUB ONLY (WIDE) SUB ONLY (WIDE)
SUB ONLY (WIDE)
The LFE channel is reproduced by the subwoofer only. There is no filtering of the LFE channel. This is an
appropriate setting when the input comes from the Sum output of another K+H subwoofer, or from
equipment with its own bass management, such a surround sound processor or DVD/Blue-ray disk player
(usually the “Subwoofer” output). Additionally, this mode is useful for detecting higher frequency signals
(up to 300 Hz) in the LFE channel that should otherwise be avoided.
1. LFE → SUB + L/R (>80)
2. LFE → SUB ONLY (<80)
3. LFE → SUB ONLY (<120)
4. LFE → SUB ONLY (WIDE)
80 Hz20 Hz 120 Hz
L/R at
-6 dB
LF
LFLF
LFE Channel Mode Settings
E Channel Mode SettingsE Channel Mode Settings
E Channel Mode Settings
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