User Guide

Surround basics
171
Subwoofers - bottom end bliss
In 5.1 format, the low bass channel serves to expand
the low end and - in (home) movie theater
applications - render effects. In the latter case, the
bass channel is also called the low frequency effects
(LFE) channel.
Low bass frequencies are filtered out of the
remaining channels and transmitted exclusively via
the frequency limited subwoofer channel. As a
result, the volume of the five main speakers (or
satellites) can be reduced significantly.
In Neuron, you can determine the subwoofer’s upper
frequency limit via menu.
Excerpts from recommendation ITU 775...
for studio and home multi-channel audio
productions. Note that all parameters relate to a very
small sweet spot!
Though the requirements for a studio environment
are more demanding, the parameters translate
reasonably well to home use.
Requirements for a surround room:
Area ................................................... > 25 m
2
Room volume ......................................> 300 m
3
Reverberation time ... 0.2-0.4 s (200 Hz - 2.5 kHz)
Early reflections ..........-10 dB to the direct sound
Speaker array:
Reference array in accordance with 3/2
recommendation (L/C/R and LS/RS) with five
identical speakers.
LFE channel:
The most common extension of the 3/2 recommen-
dation using a subwoofer. Narrow bandwidth. Neuron
lets you adjust the subwoofer’s upper frequency limit
(see page 176). The standard does not mandate a
fixed position for the subwoofer because the human
ear has trouble pinpointing the source of low fre-
quencies.
Neuron.book Seite 171 Montag, 23. Dezember 2002 2:28 14