Pioneer SC-82 User's Guide download pdf (Page 14)

Introduction MCACC MCACC ProThe Essence of MCACC Advanced MCACC Feature Comparison Technical Details

MCACC Reference Guide

Standing Wave Control

In a normal room, standing waves occur between parallel

surfaces such as ceiling/floor and facing walls; a factor that

greatly influences sound quality. The standing waves in the low

frequency range are especially difficult to control with general

sound processing methods, and there was no way but to listen

to the negatively-affected sound. Advanced MCACC captures up

to three largest standing waves, and applies compensation

curves with the opposite characteristics to eliminate the

influence.

With Advanced MCACC, the EQ compensation curve is

moderately set (Envelope Curve), and is not suited to adjusting a

certain frequency like standing waves. For Standing Wave

Control, a filter with a steep correction curve is used to avoid

over-compensating the effects of the standing waves.

1.5

0.5

0.5 1 1.5 2 2.5 3

−0.5

−1

−1.5

1.5

0.5

0.5 1 1.5 2 2.5 3

−0.5

−1

−1.5

1.5

0.5

0.5 1 1.5 2 2.5 3

−0.5

−1

−1.5

1.5

0.5

0.5 1 1.5 2 2.5 3

−0.5

−1

−1.5

Standing wave: When the sound wave emitted from the speaker reflects off the

wall, ceiling, or floor, the incident wave and reflected wave interfere and cause a

phenomenon that intensifies or weaken the wave. In such cases, standing waves

occur at a certain distance from the reflecting surface. Standing waves have

nodes and antinodes, with minimum amplitude at a node, and maximum

amplitude at an antinode. On the graphs, incident wave is in red, reflected wave

in green, the added total wave in blue. The four graphs show chronological

changes, with the horizontal axis representing points. For example, the blue

wave’s amplitude at 0.75 point from left remains unchanged at 0 (node), even as

the time passes and the incident wave’s amplitude changes. The amplitude

becomes maximum at points 0.5 or 1 for example, thus creating an antinode.

In a regular shaped room, standing

waves occur between the ceiling

and the floor, and between the walls

Standing waves

EQ Overcompensation Example

(no standing wave control)

Pioneer’s EQ adjustment uses the Envelope Compensation

method with emphasis on phase characteristics. Since a low

Q filter is applied, if standing waves exist in a certain

frequency, the surrounding frequencies are also affected

during the adjustment. As a result, the volume of the bass

sound may be overly reduced.

So first using a compensation filter pinpointing on a specific

frequency, only the standing waves are lowered.

Then, EQ adjustment is applied after Standing Wave Control.

In this way, frequency characteristic adjustment is done

without reducing the volume of the bass.

Effects of Standing Wave Control

−

70.0

20 100 1k 10k

Frequency［Hz］

Amplitude［dB］

20k

−

130.0

EQ OFF (Standing Wave Control: OFF)

EQ OFF STW OFF

Standing wave occurs

−

80.0

20 100 10k

Frequency［Hz］

Amplitude［dB］

20k

−

140.0

EQ only (Standing Wave Control: OFF)

EQ ON STW OFF

Standing waves still left

−

80.0

20 100 10k

Frequency［Hz］

Amplitude［dB］

20k

−

140.0

EQ + Standing Wave Control: ON

EQ ON STW ON

No standing waves

1 2 ... 9 10 11 12 13 14 15 16 17

Comments to this Manuals

No comments

Pioneer SC-82 User's Guide Page 14

Comments to this Manuals

Related products and manuals for Subwoofers Pioneer SC-82