User Manual

Multichannel Monitoring Tutorial Booklet (M2TB) rev. 3.5.2

Masataka Nakahara : SONA Corporation

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4. Bass management

In a small- to medium-sized studios, room modes due to standing waves often become a problem, and it is

easy for inconsistencies to develop in the low-frequency response of each speaker.

This can impair the following important requirements for multi-channel monitoring.

1. That all channels have a consistent response.

2. That the LFE playback level maintain a gain equal to the low-frequency response of the other channels

plus an additional 10 dB. (such as DVD-V and film)

Thus, ensuring that the low-frequency response of each channel is consistent is one of the most important

points for constructing a multi-channel monitoring environment.

This is why we need to consider some type of “bass management.”

In a small- to medium-sized studios, we can consider three methods of bass management; acoustical

treatment of the room, speaker placement, and electro-acoustic methods.

4-1. Acoustical treatment of the room

Room acoustics can be treated by adding thick acoustically absorptive material or by significantly

inclining the walls.

In theory, an 85 cm or greater thickness of absorptive material is required in order to completely absorb

low frequencies in the 100 Hz region.

However as the room size becomes smaller, physical considerations often make it more difficult to add

thicker absorptive material.

4-2. Speaker placement

The low-frequency response of a speaker has a closely-linked effect on the room acoustics.

Thus, consideration of the speaker placement is a useful way to improve the low-frequency playback

response.

In many cases, we are able to consider only the placement of the sub-woofer, which allows a high degree

of freedom in its placement.

Consideration of the sub-woofer placement in conjunction with the use of a bass management controller

(discussed later) is one of the most effective ways in which a small- or mid-sized studio can improve its

low-frequency response.

4-3. Electro-acoustic methods

The bass management controller shown in [Fig. 19] can be applied to a monitor system to implement

electro-acoustic compensation.

In general, bass management refers to processing by a bass management controller.

[Fig. 35] Bass management controller (1)

LFE

SUB

+10dB

HPF

LPF

HPF