MCACC Reference Guide (Update Version)

MCACC (Multi-Channel ACoustic Calibration system)

Reference Guide
• Introduction
- MCACC
- Advanced MCACC
- MCACC Pro

• The Essence of MCACC

- Phase Characteristic
- Measurement Precision
- Reproduction Frequency

• MCACC

• Advanced MCACC

• MCACC Pro

• MCACC/Advanced MCACC/MCACC Pro Feature Comparison

• Technical Details

1
 MCACC Reference Guide (Update Version)

Introduction
MCACC Overview

Introduction
To get the best results from a home theater system, it needs to
be fine-tuned, just like a musical instrument, for accurate
reproduction of sound as the original artists intended. Yet, this is
no easy task in a household multi-channel environment with all Optimize Speakers’
the speakers, furniture, the size and shape of the room, and Characteristics
various other issues. That’s why Pioneer developed MCACC
(Multi-Channel ACoustic Calibration system), a unique system
which measures and analyses the reverb characteristics of the
Optimize Room Acoustic &

The Essence of MCACC

speakers, and optimally tunes the sound output to make it just
Source Condition
right for the room.
Optimize AV Receiver’s
MCACC was originally introduced in 2001 as the world’s first Performance
automatic sound acoustic correction technology. With the
addition of Phase Control technology which compensates the
phase lag of the low-frequency signals, multi-channel sound is
now further optimized to bring out the best from your home
theater. MCACC is now available at three levels—MCACC,
Advanced MCACC, and MCACC Pro—in accordance with the
grade of the AV receiver.

MCACC
MCACC—Basis of Acoustic Field Correction
With a dedicated microphone, MCACC measures
the speaker size, level, and distance and
automatically compensates for the difference.
The delay of the subwoofer sound is also adjusted to be in
phase with the other channels.

Details on page 5

Advanced MCACC
Advanced MCACC—Precise Speaker Drive and
Advanced Correction for the Listening Environment
Advanced MCACC features a 3D calibration
method with even more precise measurements
by including the time axis, as well as Auto Phase
Control Plus for real-time analysis and automatic
compensation, Standing Wave Control for reducing unwanted

MCACC Pro
resonance, and Subwoofer EQ for adjusting the LFE tone.

Details on page 6, 7

MCACC Pro—Professional Level Correction from

Source Material to Speaker Output
In addition to the above features, MCACC Pro
Feature Comparison

goes a step further by analyzing the phase and

group delay characteristics due to network
filtering to precisely control phase differences
between speakers. The result is the sound coherence of full-
range speakers while retaining the wide frequency range
advantage of multi-way speakers. This correction is also
performed between channels, providing a smooth flow of sound
as if all delivered from the same type of speaker. Other features
include independent correction for dual subwoofers, and speaker
position adjustment in 1-millimeter increments. MCACC Pro
corrects phase differences in all ranges and all channels, from
phase difference in the original audio material to the sound
Technical Details

emitted from the speakers.

Details on page 8, 9, 10

2
 MCACC Reference Guide (Update Version)

MCACC—Acoustic Field Correction at All Levels

Introduction
Source AV Receiver Speakers

The Essence of MCACC

Auto Phase Control Plus
Speaker Adjustment
Equalizer

MCACC
Phase Control
Speaker Polarity Check
Standing Wave Control

Advanced MCACC
Subwoofer Equalizer
Independent Dual Subwoofer Output
Full Band Phase Control

MCACC Pro
Feature Comparison
Technical Details

3
 MCACC Reference Guide (Update Version)

The Essence of MCACC

Pioneer is dedicated to making your home theater experience as
close as possible to what the sound creators and studio

Introduction
engineers intended when they created the original sound tracks.
Developed through a rigorous pursuit of the ideal multi-channel
audio reproduction, the MCACC technology focuses on three main
features—phase characteristic, measurement precision, and
reproduction frequency—which sets it apart from other similar
technologies.

The Essence of MCACC

Phase Characteristic An Example of the Phase Problem

When audio signals are out of phase, cancelling out of sound Related Bass Output from Two Speakers
occurs between speaker units and channels, and the original
In Phase
sound cannot be reproduced. Pioneer’s MCACC can make Perceived
synthetic sound
adjustments without altering the phase characteristics, thereby (in green)
allowing original sound reproduction just as the creator
intended. Main Channel

More details on page 13

Free from cancellation
LFE Channel
(From subwoofer) Matching phase Powerful and accurate bass

Measurement Precision Out of Phase

MCACC
Perceived
synthetic sound
In a normal living room environment, the reverberation (in black)
characteristic is inconsistent due to various interior materials
and furniture placement. So the optimum sound quality cannot Main Channel
be achieved if the EQ is based on measurement data that
includes reverberant sound. The measurement for Pioneer’s
LFE Channel Cancellation occurs
MCACC takes the time-axis into account and applies different Phase shift between main and LFE channels
(From subwoofer)
compensation methods according to the influence of the
reverberant sound, enabling optimal compensation for the

Advanced MCACC
listening environment.

More details on page 14

Reproduction Frequency
When EQ adjustment is applied to high-resolution audio
sources, the sound quality cannot be maintained if the
reproduction frequency is reduced from the original 192 kHz or
96 kHz level. Pioneer’s MCACC makes EQ adjustment without
changing the audio file’s reproduction frequency, allowing

MCACC Pro
playback of true high-resolution sound in a multi-channel setup.

Feature Comparison
Technical Details

4
 MCACC Reference Guide (Update Version)

MCACC
Speaker Adjustment (size, level, distance, crossover) Acoustic Calibration by MCACC

Introduction
Create the optimum acoustic environment with Pioneer’s Before Calibration After Calibration
Speaker distance, sound pressure level, and Speaker distance, sound pressure level, and
MCACC, developed with the expertise of professional recording frequency response are all uneven. frequency response are all equalized.
studios. The system — complete with custom microphone —
automatically compensates for differences in speaker size, level The sound field is automatically
measured using the supplied mic.
and distance, and equalizes response.
SET-UP SET-UP
MIC MIC
More details on page 12 Calibration

The Essence of MCACC

Speaker sizes and number of
speakers are automatically detected.

Equalizer
The frequency response of each speaker is measured and
adjusted for all bands. This is completed with the original
Envelope Compensation applied technology, which ensures
optimum timbre-matching with minimum phase variation
among channels.

More details on page 13

MCACC
Phase Control The "Phase Control" Compensates for the Delay of Low-Frequency Sound
Source AV Receiver
When amplifying multi-channel audio signals, Speakers
receivers use a Low Pass Filter (LPF) to process
low-frequency signals for subwoofer output. This
causes “phase lag” — a delay of approximately 5
msec — of the low-frequency signals compared

Advanced MCACC
to the main channel signals. As a result, the delayed bass makes
the sound lack synchronization. Pioneer’s Phase Control
technology effectively eliminates phase lag and significantly
improves the multi-channel sound without any extra operation.
PHASE CONTROL

Problems occur even with an ideal content which has no LFE delay. Phase Control
solves this within the AV receiver.

MCACC Pro
Feature Comparison
Technical Details

5
 MCACC Reference Guide (Update Version)

Advanced MCACC
Speaker Adjustment (size, level, distance, crossover) Acoustic Calibration by MCACC

Introduction
Create the optimum acoustic environment with Pioneer’s Before Calibration After Calibration
Speaker distance, sound pressure level, and Speaker distance, sound pressure level, and
MCACC, developed with the expertise of professional recording frequency response are all uneven. frequency response are all equalized.
studios. The system — complete with custom microphone —
automatically compensates for differences in speaker size, level The sound field is automatically
measured using the supplied mic.
and distance, and equalizes response.
SET-UP SET-UP
MIC MIC
More details on page 12 Calibration

The Essence of MCACC

Speaker sizes and number of
speakers are automatically detected.

MCACC Reverberation Characteristics

Before Calibration After Calibration
Equalizer
Level (dB) Level (dB)
The frequency response of each speaker is measured and Reverb Reverb

adjusted for all bands. This is completed with the original

Envelope Compensation applied technology, which ensures
optimum timbre-matching with minimum phase variation
among channels. In addition to the calibration for frequency
response of MCACC, the Advanced MCACC features the time-axis Time (msec)

MCACC
Time (msec)

compensation, allowing manual or automatic point control of Frequency (Hz) Frequency (Hz)

acoustic treatment between 0 msec and 80 m sec points in 20

msec units. Minute adjustment allows you to create an ideal
sound field according to the acoustic characteristics of various
listening environments.

More details on page 13

Advanced MCACC
Phase Control The "Phase Control" Compensates for the Delay of Low-Frequency Sound
Source AV Receiver
When amplifying multi-channel audio signals, Speakers
receivers use a Low Pass Filter (LPF) to process
low-frequency signals for subwoofer output. This
causes “phase lag” — a delay of approximately 5
msec — of the low-frequency signals compared
to the main channel signals. As a result, the delayed bass makes
the sound lack synchronization. Pioneer’s Phase Control
technology effectively eliminates phase lag and significantly

MCACC Pro
improves the multi-channel sound without any extra operation.
PHASE CONTROL

Problems occur even with an ideal content which has no LFE delay. Phase Control
solves this within the AV receiver.

Auto Phase Control Plus Effect of Auto Phase Control Plus (data comparison)
During Blu-ray Disc/DVD/multi-channel file Original disc playback Playback with Auto Phase Control Plus
Level

Level

playback, Auto Phase Control Plus makes real-time

Feature Comparison

analysis of the phase difference between the LFE

(low frequency effect) and the main signals, and
automatically compensates the gap. Elimination of Front L Front L

phase lag enhances strong bass and clear high-

frequency sound — especially effective for audio content such as LFE LFE

live performance and music video clips.

* Effectiveness depends on content Delay setting: 0 msec Time Delay setting: 9 msec Time

Superior sound provided by compensating the lag in the subwoofer channel on the disc.
More details on page 14
Technical Details

Speaker Polarity Check

The Advanced MCACC will check the speaker polarity for proper
connection. “Reverse Phase” will be displayed on the GUI screen
if the speaker’s wiring (+ and -) is inverted.

6
 MCACC Reference Guide (Update Version)

Standing Wave Control Standing Wave in a Typical Listening Room

Acoustic standing waves occur when the sound waves from
your speaker resonate with those reflected off the walls.

Introduction
Depending on the speaker placement, your listening position or
the shape of the room, standing waves have a negative effect on
the overall sound, especially in certain lower frequencies.
Standing Wave Control effectively decreases resonance and
prevents inaccurate EQ-setting calibration.

More details on page 15

The Essence of MCACC

= Standing Waves

Subwoofer Equalizer
This new EQ feature allows you to adjust the subwoofer tone.
For Auto MCACC, the subwoofer EQ is automatically adjusted
with EQ type ALL CH ADJ, while manual adjustment is available
with EQ type SYMMETRY and FRONT ALIGN. As with other EQ,
the manual adjustment can be done on the AV receiver’s GUI.

MCACC
Advanced MCACC
MCACC Pro
Feature Comparison
Technical Details

7
 MCACC Reference Guide (Update Version)

MCACC Pro
Speaker Adjustment (size, level, distance, crossover) Acoustic Calibration by MCACC

Introduction
Create the optimum acoustic environment with Pioneer’s Before Calibration After Calibration

MCACC, developed with the expertise of professional recording Speaker distance, sound pressure level, and Speaker distance, sound pressure level, and
frequency response are all uneven. frequency response are all equalized.
studios. The system — complete with custom microphone —
automatically compensates for differences in speaker size, level The sound field is automatically
and distance, and equalizes response. When using Dolby Atmos measured using the supplied mic.

enabled speakers, the reflex path distance is calculated from the SET-UP SET-UP
MIC
MIC Calibration
automatically measured direct distance, and the vertical
distance between the ceiling and the speaker entered by the

The Essence of MCACC

Speaker sizes and number of
speakers are automatically detected.
user. As a result, the timing of the reflex path’s sound is
matched with direct sound, allowing accurate reproduction of
the sound objects’ movement effect on Dolby Atmos.
MCACC Reverberation Characteristics
More details on page 12 Before Calibration After Calibration

Level (dB) Level (dB)

Reverb Reverb

Time (msec) Time (msec)

Frequency (Hz) Frequency (Hz)

MCACC
Equalizer
Distance Adjustment System for Dolby Atmos Enabled Speakers
The frequency response of each speaker is measured and
Ceiling
adjusted for all bands. This is completed with the original
Envelope Compensation applied technology, which ensures
optimum timbre-matching with minimum phase variation
among channels. In addition to the calibration for frequency Reflex path distance
Automatically
response of MCACC, MCACC Pro features the time-axis
calculated
compensation, allowing manual or automatic point control of

Advanced MCACC
acoustic treatment between 0 msec and 80 m sec points in 20
Distance to ceiling
msec units. Minute adjustment allows you to create an ideal
Manual input
sound field according to the acoustic characteristics of various
listening environments.

More details on page 13

Direct distance
Automatically measured
Reflex path distance automatically calculated to maximize Dolby
Atmos sound effect
Phase Control

MCACC Pro
The "Phase Control" Compensates for the Delay of Low-Frequency Sound
When amplifying multi-channel audio signals,
receivers use a Low Pass Filter (LPF) to process Source AV Receiver
Speakers
low-frequency signals for subwoofer output. This
causes “phase lag” — a delay of approximately 5
msec — of the low-frequency signals compared
to the main channel signals. As a result, the delayed bass makes
the sound lack synchronization. Pioneer’s Phase Control
technology effectively eliminates phase lag and significantly
Feature Comparison

improves the multi-channel sound without any extra operation.

PHASE CONTROL

Problems occur even with an ideal content which has no LFE delay. Phase Control
solves this within the AV receiver.
Auto Phase Control Plus
During Blu-ray Disc/DVD/multi-channel file Effect of Auto Phase Control Plus (data comparison)
playback, Auto Phase Control Plus makes real-time Original disc playback Playback with Auto Phase Control Plus
Level

Level

analysis of the phase difference between the LFE

Technical Details

(low frequency effect) and the main signals, and

automatically compensates the gap. Elimination of
phase lag enhances strong bass and clear high- Front L Front L

frequency sound — especially effective for audio content such as

live performance and music video clips. LFE LFE

* Effectiveness depends on content

Delay setting: 0 msec Time Delay setting: 9 msec Time
More details on page 14 Superior sound provided by compensating the lag in the subwoofer channel on the disc.

8
 MCACC Reference Guide (Update Version)

Speaker Polarity Check

The Advanced MCACC will check the speaker polarity for proper
connection. “Reverse Phase” will be displayed on the GUI screen

Introduction
if the speaker’s wiring (+ and -) is inverted.

Standing Wave Control Standing Wave in a Typical Listening Room

Acoustic standing waves occur when the sound waves from
your speaker resonate with those reflected off the walls.
Depending on the speaker placement, your listening position or

The Essence of MCACC

the shape of the room, standing waves have a negative effect on
the overall sound, especially in certain lower frequencies.
Standing Wave Control effectively decreases resonance and
prevents inaccurate EQ-setting calibration.

More details on page 15

= Standing Waves

Subwoofer Equalizer
This new EQ feature allows you to adjust the subwoofer tone.

MCACC
For Auto MCACC, the subwoofer EQ is automatically adjusted
with EQ type ALL CH ADJ, while manual adjustment is available
with EQ type SYMMETRY and FRONT ALIGN. As with other EQ,
the manual adjustment can be done on the AV receiver’s GUI.

Independent Dual Subwoofer Output

When connecting an additional subwoofer to increase the bass,

Advanced MCACC
the two subwoofers may not be at a same distance. In such a
case, cancelling out of the bass may occur and prevent you from
perceiving the full effect of the additional subwoofer. MCACC
Pro supports independent adjustment for each subwoofer,
offering optimal performance for a dual-subwoofer setup. You
can enjoy free placement of your subwoofers.

Bass Management System Without Bass Management

No horizontal sound localisation
MCACC Pro has a special Bass Management System for Dolby
Atmos enabled speakers, routing the low-frequency Ideal sound

MCACC Pro
components to the floor speaker below and the subwoofer. image
Usually, the low-frequency components are all redirected to the
subwoofer. Since this will include frequencies featuring
directivity, the resulting sound lacks a seamless feel. Pioneer’s Auditory sound
image
Bass Management System on MCACC Pro redirects the low-
frequency component with directionality to the floor speaker
placed beneath the Dolby Atmos enabled speaker element,
providing a smooth bass response. This superior sound
localization will maximize the advantage of Dolby Atmos
Feature Comparison

content.
Pioneer-Exclusive Bass Management System
for Dolby Atmos enabled speakers
With Bass Management
Horizontal sound localisation achieved
Mid-High
Pioneer
80 Hz 180 Hz
Bass
Deep Bass Mid-High Ideal sound image
Dolby Atmos Bass
enabled speaker = Auditory sound
sound component
3 Parts
Deep
Bass Subwoofer
image
Technical Details

Other Brands
20 Hz 20 kHz
Mid-High
150 Hz

Bass Mid-High
Deep Bass

2 Parts
Bass
Deep Bass Subwoofer

9
 MCACC Reference Guide (Update Version)

Full Band Phase Control Full Band Phase Control Off Full Band Phase Control On

The further advanced Full Band Phase Control technology

focuses on the group delay in the speaker network filter, and

Introduction
TWEETER TWEETER
compensates with special digital signal processing (DSP), to (+) (+)

adjust the phase of each unit as well as the group delay for each
MIDRANGE MIDRANGE
speaker. Full Band Phase Control gives multi-range speakers the (+) (+)

sound coherence of full-range speakers, while retaining the wide

frequency range advantage. WOOFER
(+)
WOOFER
(+)

More details on page 16

The Essence of MCACC

Adjusts group delay for each unit

Precision Distance
Precision Distance is an innovative, world’s first feature for
making millimeter-level manual adjustments to speaker
distance. You can easily duplicate a skilled installer’s precise
positioning with the help of a level gauge shown on the display.
* Only available for some models

MCACC
Advanced MCACC
MCACC Pro
Feature Comparison
Technical Details

10
 MCACC Reference Guide (Update Version)

MCACC/Advanced MCACC/MCACC Pro Feature Comparison

MCACC Pro Advanced MCACC MCACC

Introduction
Speaker Adjustment (size, level, distance, crossover) • • •
Equalizer 3D 3D 2D
Phase Control • • •
Auto Phase Control Plus • • —
Speaker Polarity Check • • —
Standing Wave Control • • —

The Essence of MCACC

Subwoofer Equalizer • • —
Independent Dual Subwoofer Output • — —
Bass Management System • — —
Full Band Phase Control • — —
Precision Distance • — —

MCACC
Advanced MCACC
MCACC Pro
Feature Comparison
Technical Details

11
 MCACC Reference Guide (Update Version)

Technical Details
Speaker Adjustment

Introduction
MCACC applies the most suited test signal for each item to
make measurements.

Speaker Size Detection Low Frequency Linearity Measurement

With MCACC, the speaker size is detected by a general method

using frequency characteristics. In addition to the measurement Power maintained at lower frequency:

The Essence of MCACC

by MCACC, Advanced MCACC and MCACC Pro check the detected as Speaker Large
linearity, and more precisely measures the ability for low

Output Power
frequency playback. Speaker A
Speaker B

Input Power

Speaker Distance Adjustment L R With a 2ch system, all points on

Why does precise adjustment of the speaker distance improve the bisector are at equal distance

MCACC
the balance of the whole sound field in your listening space? On a stereo system, a set of points
That’s because with a multi-channel speaker system, a single with equal distance from the two
speakers becomes a straight line as
speaker placed at a different distance from the other speakers
shown on left. So it is relatively easy
can have an adverse effect to all the other speakers, and distort to gain the point where the sound
the sound field for the whole system, as shown on right. In waves from all sound sources (two
reverse, if all the speakers are at an equal distance, the phase speakers) intersect in phase.
will be aligned. As a result, the sound improves not only at the
listening spot where the microphone is placed, but also in the With a 3ch system, the intersection of two
whole listening area by optimized balance of the sound field.

Advanced MCACC
bisectors needs to be at an equal distance
L R
With a 3ch system, the intersection of the
Pioneer is one of the few manufacturers providing speaker bisector between L and R and the bisector
distance measurement in 1 cm-increment. What’s more, between R and SR, point A, is where the
sound wave from all sound sources
Pioneer’s Precision Distance is the only technology allowing
intersects in phase, as shown with a red
millimeter-level manual adjustment to the speaker distance. triangle. The bisector between L and SR
automatically passes through this point.

A With a 4ch system, the additional channel

must precisely match the point fulfilling
the condition for 3ch
With 4 or more channels, the distance for
the additional channel(s) (shown with the

MCACC Pro
green arrow) must precisely match the
already affixed point A for 3ch. So it
becomes more difficult to achieve the point
SL SR
where the sound waves from all sound
sources intersect in phase.

The ideal is to have a spot with the same acoustic distance from all speakers

Interference on other
channels distort the sound field
Feature Comparison

L R L R

SL ch out of phase
Technical Details

SL
SL SR SR

All channels are in phase, with ideal sound field

Distorted overall sound field
for all channels

12
 MCACC Reference Guide (Update Version)

Crossover Frequency Adjustment

Comparison of Subwoofer Output
Using the measured result, one suitable parameter is set for all Timing of LFE assigned to
SW from each main speaker
the speakers. This helps to prevent cancelling out of the bass

Introduction
sound caused by a phase shift. Other manufacturers use Front Other Brand Interference Less power
separate filters for each channel. This is fine when all the
speakers are of the same type, but with various types of SW output
Center
speakers, the timing of the bass will be inconsistent, causing Mix Result
cancelling out with a loss of the bass sound.
Surround

No interference Powerful bass

Front Pioneer

The Essence of MCACC

SW output

Center
Mix Result

Surround

Equalizer (Frequency Characteristic Adjustment) Pioneer’s Envelope Compensation vs. Peak/Dip Correction

The frequency characteristic for each channel is adjusted using Level/frequency characteristic before correction
the 9-band EQ, which has minimal effect on the phase
characteristic while achieving optimum performance. As shown
on right, the general peak/dip correction method is good at

MCACC
matching the frequency characteristics, but making detailed
adjustments on every peak and dip for each speaker will cause
phase shifts and deteriorate sound localization. In contrast,
Pioneer’s MCACC performs a frequency characteristic
adjustment using the Envelope Compensation technology with
Pioneer’s Envelope Compensation General Peak/Dip Correction
low Q filter. This minimizes the effect on the phase, providing a Level/frequency characteristic after correction
natural and smooth adjustment in a multi-channel playback
environment.

Advanced MCACC
Phase/frequency characteristic after correction

Features
Less distortion in phase/frequency The level/frequency characteristic is matched,

MCACC Pro
characteristic, resulting in reduced timing but the phase/frequency characteristic is
mismatch for multi-channel playback. largely distorted. This phase shift means
timing mismatch, with greater influence for
multi-channel playback using more speakers.

Feature Comparison
Technical Details

13
 MCACC Reference Guide (Update Version)

3D Time-Axis Compensation
Before Calibration
As shown on the 3D graphs on right, the frequency characteristics
change with the passing of time. So if compensation is made on the

Introduction
same point of the time-axis, there will be some difference due to
reverberation. To solve this problem, Advanced MCACC adopts the 3D
Time-Axis Compensation which takes into account this change along
the time-axis. You can measure the listening environment before
correcting the sound field, and make compensations matched to the
condition. The adjustment can be done in 0 to 160 msec range
including the direct sound area, allowing compensation with
emphasis on direct sound. The adjustment point can be controlled

The Essence of MCACC

manually for minute adjustments suited to the listening environment.
The measured results can be displayed in a rotatable 3D graph on your
personal computer or iPad via the AVNavigator or iControlAV5 app.
Anyone can easily use the professional features such as display After Calibration
before/after calibration comparison, or check if each frequency
characteristic is aligned at the setup point on the time-axis.

MCACC
Advanced MCACC Reverberation Measurement Result

Advanced MCACC
Auto Phase Control Plus Effect of Auto Phase Control Plus (data comparison)
Multi-channel sounds on Blu-ray Discs, DVDs, or 5.1ch WAV/FLAC are Original disc playback Playback with Auto Phase Control Plus
Level

Level

sometimes recorded with LFE channel delay (about max. 16 msec)

caused by the LPF (low-pass filter) when the discrete sounds are
packaged. This delay in the low frequencies affects not only the bass,
but also the main channel playback, dulling the rhythm and sound. Front L Front L

During playback, Phase Control Plus technology automatically adjusts

MCACC Pro
and compensates the phase lag (group delay) included in the sound LFE LFE

source, from 0 to 16 msec in 1 msec increments. In addition to solving

the phase lag (group delay) in audio devices such as AV receivers and Delay setting: 0 msec Time Delay setting: 9 msec Time
speakers, the phase shift sometimes included in discs or broadcasts
Superior sound provided by compensating the lag in the subwoofer channel on the disc.
can also be adjusted, allowing precise control of every phase, from
audio source to output. With the synergy effect of the original Phase
Control compensation, all sounds are aligned, providing better
balance for the overall reproduced sound, exceptionally powerful and
dynamic bass, and clear high frequencies.
Feature Comparison
Technical Details

14
 MCACC Reference Guide (Update Version)

Standing Wave Control 2 2

1.5 1.5
1 1
In a normal room, standing waves occur between parallel 0.5 0.5
surfaces such as ceiling/floor and facing walls; a factor that

Introduction
0 0
greatly influences sound quality. The standing waves in the low −0.5 −0.5
−1 −1
frequency range are especially difficult to control with general
−1.5 −1.5
sound processing methods, and there was no way but to listen
0.5 1 1.5 2 2.5 3 0.5 1 1.5 2 2.5 3
to the negatively-affected sound. Advanced MCACC captures up
to three largest standing waves, and applies compensation 2 2
1.5 1.5
curves with the opposite characteristics to eliminate the
1 1
influence. 0.5 0.5
0 0

The Essence of MCACC

−0.5 −0.5

In a regular shaped room, standing −1 −1

−1.5 −1.5
waves occur between the ceiling
and the floor, and between the walls 0.5 1 1.5 2 2.5 3 0.5 1 1.5 2 2.5 3

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
Standing waves 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
With Advanced MCACC, the EQ compensation curve is 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.
moderately set (Envelope Curve), and is not suited to adjusting a
certain frequency like standing waves. For Standing Wave

MCACC
Control, a filter with a steep correction curve is used to avoid
over-compensating the effects of the standing waves.
Effects of Standing Wave Control

EQ Overcompensation Example
EQ OFF STW OFF
(no standing wave control) Standing wave occurs
－70.0

Amplitude［dB］

Advanced MCACC
－130.0
20 100 1k 10k 20k
Frequency［Hz］

EQ OFF (Standing Wave Control: OFF)

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.
EQ ON STW OFF
Standing waves still left
－80.0

MCACC Pro
Amplitude［dB］

－140.0
20 100 1k 10k 20k
Frequency［Hz］

EQ only (Standing Wave Control: OFF)

Feature Comparison
So first using a compensation filter pinpointing on a specific
frequency, only the standing waves are lowered.

EQ ON STW ON
No standing waves
－80.0
Amplitude［dB］

－140.0
20 100 1k 10k 20k
Frequency［Hz］
Technical Details

EQ + Standing Wave Control: ON

Then, EQ adjustment is applied after Standing Wave Control.
In this way, frequency characteristic adjustment is done
without reducing the volume of the bass.

15
 MCACC Reference Guide (Update Version)

Full Band Phase Control Three-Step Processing within the AV Receiver

While Phase Control’s bass management technology controls Measurement Step 1
the LFE channel timing and phase within the AV receiver, the Full

Introduction
Special sweep signal output from
Band Phase Control’s technology has further evolved to control
each speaker
the phase of all the units of the multi-way speaker system. With
a normal multi-way speaker system, the audio signals are
separated with the network filter inside the speaker and routed Signals measured with dedicated
to each unit. However, group delay occurs between the units due mic
to this processing through the network filter. Using a
microphone, Full Band Phase Control automatically measures Digital Signal Processing (DSP)
and analyzes the group delay that occurs across the whole of measured signals

The Essence of MCACC

frequency range, then compensates only the phase
characteristics without affecting the frequency characteristics,
by adjusting with a FIR filter. As a result, multi-way speakers Impulse response gained from
sound coherent like full-range speakers, while retaining their each speaker
advantage of the wide frequency range—a significant
advancement in sound quality. Measurement Step 2

Full Band Phase Control Off Full Band Phase Control On

Calculate phase characteristics <Measured Phase Characteristics>
from impulse response
180

Extract the optimal model from

TWEETER TWEETER
(+) (+) 0
the approx. 5,500 phase models
MIDRANGE MIDRANGE
(+) (+) (99 % of the commercially available speakers)
–180 Frequency
Less influence from room environment

MCACC
S
WOOFER WOOFER
(+) (+) S Avoiding overcompensation allows
adjustment without deteriorating sound
quality <Estimated Phase Characteristics>

180
Adjusts group delay for each unit
Calculate the inverse filter factor for
adjusting the selected phase model 0
When the frequency range is separated via the network filter on
a multi-way speaker, although the total frequency characteristic S Allows compensation for only the phase
component by creating an all-pass FIR filter –180
is designed to be flat, the phase and group delay characteristics

Advanced MCACC
Frequency
are not flat. As shown on right, Full Band Phase Control solves
this in three steps by using the MCACC microphone and DSP to Measurement Step 3
measure, analyze, and make compensations.
Apply FIR filter with the calculated
filter factor to each channel
Frequency Characteristic and Impulse Response of a General
3-Way Speaker Impulse response
Phase and group delay for each before compensation
speaker is adjusted to have the ideal
Low- Mid- High- characteristics of a full-range speaker
range range range

MCACC Pro
Sound field with matched phase
and group delay characteristics Impulse response
for all speakers achieved after compensation

High Frequency
(tweeter) Phase
G delay
11247
13214
15525
18240
1002
1178
1384
1626
1910
2244
2637
3098
3639
4276
5024
5902
6936
8148
9573
200
235
276
324
381
448
526
618
726
853

Mid Frequency 1000 0.004

(midrange) 0 0.0035

－1000 0.003

－2000 0.0025
Feature Comparison

－3000 0.002

Because of group delay due to the network －4000 0.0015

Input impulse waveform －5000 0.001

filter, the sound output order is: high-range, －6000 0.0005

mid-range, low-range. －7000 0

－8000 －0.0005
Low Frequency －9000 －0.001
(woofer)
Speaker phase & group delay
The phase and group delay adjustment of Full Band Phase characteristics before
Speaker impulse response compensation
Control is applied not only to each speaker unit—simultaneous before compensation
analysis and compensation is also made between all connected Before compensation: simultaneous input for full range is
speakers. So even on a setup consisting of speakers from output in the order of high, mid, then low frequencies

various brands or series with completely different Phase

G delay

characteristics, you can enjoy a natural and seamless

11247
13214
15525
18240
1002
1178
1384
1626
1910
2244
2637
3098
3639
4276
5024
5902
6936
8148
9573
200
235
276
324
381
448
526
618
726
853

Technical Details

1000 0.004
performance as if delivered all from the same speakers. With 0 0.0035

accurate sound reproduction for the full bandwidth in all －1000 0.003

－2000 0.0025
channels, Full Band Phase Control creates the ideal sound field －3000 0.002

for multi-channel reproduction with unprecedentedly clear audio －4000 0.0015

－5000 0.001

localization and a tremendous surrounding sound. －6000 0.0005

－7000 0

－8000 －0.0005

－9000 －0.001

Speaker impulse response Speaker phase & group delay

after compensation characteristics after
Woofer Midrange Tweeter compensation
After compensation: simultaneous input for full range
16 results in simultaneous output for all frequencies

Group Delay Compensation Effect

 MCACC Reference Guide (Update Version)

Front Align—Additional Feature for Full Band Phase Front Align Setup Image
Control
Before compensation Front
Phase characteristics

Introduction
Many users like to create a speaker system with the emphasis 180
on the front speakers for music playback. Front Align is a new 0
feature added to Full Band Phase Control that matches the −180 Frequency

phase characteristic of all speakers to the front speakers. By Centre Frequency characteristics
Phase characteristics 100.0
combining with the existing “FRONT ALIGN” EQ, you can match
180 [dB]
both the frequency and phase characteristics to the front 0 20.0
10 100 1k 20k
speakers. This allows you to create a surround sound field with a −180 Frequency Frequency [Hz]

smooth feel, with focus on your favorite front speakers. Surround

Frequency characteristics
100.0 Phase characteristics
180

The Essence of MCACC

[dB]
20.0 0
10 100 1k 20k
Frequency [Hz] −180 Frequency

Frequency characteristics
100.0
[dB]
20.0
10 100 1k 20k
Frequency [Hz]

Phase characteristics Frequency characteristics

180 100.0
[dB]
0
20.0
Frequency 10 100 1k 20k
−180 Frequency [Hz]
Out of phase Different frequency characteristics

MCACC
Front
After compensation
Phase characteristics
FRONT 180

ALIGN 0

−180 Frequency

Frequency characteristics
100.0
[dB]
Centre 20.0
10 100 1k 20k
Phase characteristics Frequency [Hz]
180

Advanced MCACC
0 Surround
−180 Frequency Phase characteristics
180
Frequency characteristics 0
100.0
−180 Frequency
[dB]
20.0 Frequency characteristics
10 100 1k 20k 100.0
Frequency [Hz]
[dB]
20.0
10 100 1k 20k
Frequency [Hz]

Phase characteristics Frequency characteristics

180 100.0
[dB]
0
20.0

MCACC Pro
Frequency 10 100 1k 20k
−180 Frequency [Hz]
Compensation by maintaining the front For a natural sound, the front channel’s
channel characteristics (red) while characteristics (red) are kept the same,
aligning the other channels’ phase while the frequency characteristics of
characteristics to the front channel other channels are aligned to the
front channel
As all the speaker’s frequency and phase characteristics approximate the
front channel, a smooth multi-channel sound can be enjoyed.
Feature Comparison
Technical Details

17
 MCACC Reference Guide (Update Version)

The Synergy of Accurate Distance Adjustment and Full Band Phase Control

Introduction
Input waveform for each channel Ideal output waveform

The Essence of MCACC

Impulse response before compensation Impulse response after compensation Impulse response after compensation
with SP distance adjustment with SP distance adjustment and
Full Band Phase Control
Amplitude

Amplitude

Amplitude
SL
SR C

0.0 0.0 0.0

SBL FR
SBR FL

Impulse response still distorted due to The synergy of accurate distance

speaker group delay adjustment and Full Band Phase Control
creates almost ideal impulse response

MCACC
for all channels
* To clarify the effects, the measurement is done with irregular speaker type and distance.

Even with the same impulse input for each channel, the response waveform will be distorted without proper settings and speaker drive
control. By aligning the speakers through accurate speaker distance measurement, and matching the timing across the frequency range with
Full Band Phase Control, an ideal reproduction environment is created where the timing for all channels for the full bandwidth is matched.

Advanced MCACC
MCACC Pro
Feature Comparison
Technical Details

18