User Manual

Multichannel Monitoring Tutorial Booklet (M2TB) rev. 3.5.2
Masataka Nakahara : SONA Corporation
©2005 YAMAHA Corporation, ©2005 SONA Corporation
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[Fig. 42] Playback characteristics using Bass management controller (2)
As discussed above, bass management specifications must be determined on the basis of an overall
evaluation of numerous factors including the speakers used and the purpose of the studio. It is also
important to carefully consider filter response and sub-woofer placement taking into account how they
match the speaker, and to require the same quality of sub-woofer as the woofer units of the main speakers.
The true value of bass management appears only when careful adjustments are made to a setup in which
these factors have been taken into account.
However even in a carefully adjusted environment, it is not the case that the low-frequency portion below
80 Hz sent by the bass management controller to the sub-woofer is completely devoid of directionality. To
some extent, care taken in the placement of the sub-woofer can improve the sense of directionality, but
depending on the content, the low-frequency portion of the surround may be heard from the sub-woofer
placed in front of the listener. In particular for musical content, this is often undesirable. The region that
can be improved by bass management is the region below 80 Hz, and for the low range in the vicinity of
100 Hz, acoustical measures must be applied to the room.
Bass management is a very useful way to improve the low-range playback response in a mid- to small-scale
surround monitoring environments, but it is by no means a cure-all. Its use must be considered for each individual
case, depending on the acoustical conditions of the studio and the content of the production. In general, the
advantages are greater when it is used during post-production, and for musical applications, the decision must be
taken in view of the acoustical conditions of the room. However for music, slight phase differences in the
playback speakers can affect the production, meaning that there may be cases in which bass management
becomes a liability. The same applies to LFE; due to fears of phase change or delay resulting from the LPF, LFE
is not usually used for music.
However, regardless of whether bass management is used in the playback environment during production, a bass
management controller is equipment that a production studio should have for purposes such as verifying the
playback in the end-user environment and checking for ultra-low-frequency noise.
The Yamaha DM2000, DM1000, and 02R96 digital consoles contain a cutting-edge bass management
system that is able to respond immediately to a variety of audition environments and production media.
In order to match a variety of speakers, it allows the selection of either Butterworth or Linkwitz-Riely
filter responses, as well as 12 dB/octave or 24 dB/octave slopes for each speaker (L&R, C, LS&RS).
Monitoring conditions can be adjusted for a variety of media, for example with variable LFE or LS/RS
playback levels. In addition, bass management can easily be switched on/off, making it easy to
audition the effect of bass management. This THX pm3 Approved bass management can instantly
support the monitor system of a THX pm3 Certified Studio simply by recalling a THX preset
(DM2000, 02R96: Ver.2.1 or later, DM1000: Ver.2.0 or later).
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