Kenwood AX-7 User Manual

New concept DVD Entertainment system with Virtual Front Surround

Home Cinema has become so popular nowadays that an enormous variety of brands and models are
available in various product categories. However, in order to experience a spectacular and real
sensation in surround sound, there is a need for multiple loudspeakers that need to be located and
set-up carefully. The position of the TV monitor must also match the listening area, so as a result the
optimal listening position is limited to a very restricted area. The strict setup requirements, the
number of loudspeakers, and their size, the many wires, the complicated set-up and required
adjustment means many users are not satisfied with their current Home Cinema system.

To counter these limitations, and with 60 years of experience in the world of electronics as an expert in the
physics of audio and video, Kenwood has developed the new DVD entertainment system, AX-7. Using the third
generation of Kenwood's original development “Virtual Front Surround” (VFSIII) and the power of the digital
signal processor from Analog Devices Incorporated (ADI), Kenwood has constructed a unique algorithm for its
new front surround system. The AX-7 is able to recreate the atmosphere of surround sound for Home Cinema
with only 2 loudspeaker enclosures that incorporate a double speaker system (a 2-way 2 speaker hi-fi system
and a single full range effect speaker).
Virtual Front Surround III makes it possible to experience a flexible and spectacular surround sound without the
complicated critical set up of many speakers and without speaker cables cluttering your room

Characteristics & Specifications

C-AX7 DVD Control Pre-Amplifier

Pre-Amplifier Section

¡ Full Digital controlled Pre-Amplifier ¡ Wolfson CODEC ¡ Virtual Front Surround III ¡ Clear Voice Sound ¡ Dolby
Digital / DTS / PLII Decoders ¡ 4 Analog inputs (Line 1~2, TV, AUX) - RCA pin ¡ Digital DAP input - by Stereo mini
jack ¡ 1Analog Audio output (Line 1) ¡ 6 channel Pre-out [ (Front L/R, Surround L/R, Central, Sub-woofer)] ¡ 1
Digital Audio Output (Optical output: BitStream/PCM) ¡ Video Output (Composite, S-Video) ¡ SCART
Euroconnector adaptor (Composite + L/R RCA → SCART plug)

DVD/CD Section

¡ Front Loading ¡ DVD-Video / VCD / CD-DA / MP3 / WMA / JPEG / PHOTO CD Playback ¡ vídeo DAC of 10bit
54MHz ¡ AUDIO DAC of 24bit 96/48 kHz ¡ DVD-R/RW (DVD+R/RW) ¡ CD-R/RW Playback ¡ Repeat
(ONE,ALL,PGM,A-B), RANDOM ¡ PGM Play

Tuner Section

¡ FM: 87.5MHz - 108.0MHz ¡ AM: 531 - 1602kHz ¡ RDS

Timer

¡ SLEEP ¡ A.P.S. ¡ PROG. 1/2 (weekly timer)

Remote control unit

¡ 63 key

Dimension

¡ W 270 × H 101 × D 347 mm

Weight

¡ 5.0kg

M-AX7 Power Amplifier

Power Amplifier Section

¡ BTL two channel configuration : 50W + 50W ¡ 4 channel multi-drive: 25W x 4 ¡ Discrete Power Amplifier
topology ¡ 2 Analog Audio Input (Front - Surround)
Dimension
¡ W 270 × H101 × D 347 (mm)
Weight
¡ 5.0kg

LS-AXD7 Speaker system

Speaker Section

¡ 2way 2 speaker＋1way full range ¡ 2 way: Woofer 13cm acoustic suspension, Tweeter: 2.5cm balanced soft
dome ¡ 1 way: Full range 5cm cone suspension ¡ Detachable grill
Dimension
¡ W 164 × H 330 × D 211 mm　
Weight
¡ 3.9kg

DSP

AX-7

DVD/CD Entertainment System

The Virtual Front Surround system enables an expanded acoustic field and offers a spectacular surround
sound with only 2 front speakers.

2 way Speaker System

FL

FL+SL

FR

FR+SR

F in Virtual Front Surround F+S in Clear Voice Sound Mode

Amp li fi ca ti on C ir cu it i n Dire ct L in ea r
configuration. In the upper diagram both
amplifiers are used for the amplification of the left

Surround effect produced by new Vir tual Front
Surround III, generated by a double speaker system
incorporated in each front speaker enclosure.

and right front channels using Virtual Front

Surround, or combined with the front channel if
Clear Voice Sound has been selected. In the lower

diagram both amplifiers are used for left and right
Surround channels where VFS is selected, or for
center channel where Clear Voice Sound is
selected.

Satellite Speakers

SL

C

Spaciousness

SR

Adjustment of the surround effect (narrow or wide)

C

S in Virtual Front Surround Central in Clear Voice Sound Mode

Accessories

HD20GA7

Digital Audio Player with graphic display
screen and Clear Digital Amplifier

Kenwood has always connected with people through sound. Now we want to
expand the world of sound in ways that only Kenwood can, listening to our
customers and to the pulse of the coming age as we head toward a future of
shared discovery, inspiration and enjoyment.

All brand names and product names are trademarks,
regis tered trade marks, or trade names of the ir
respective ho lders. Kenwood follow s a policy of
continuous advancement in development. For this
reason specifications may be changed without notice.

Products introduced in this catalog may not be available in some
regions.

This catalog is printed on ecological paper.

SW-508B

Active Subwoofer

¡ 160mm double woofer

w i t h i n d e p e n d e n t
amplification ¡ Dynamic
Power: 75W+75 Watt @ 6
Ohm ¡ Bass Reflex System

¡ Adjusting frontal controls
¡ Frequency response: 60Hz

to 200 Hz

Kenwood Electronics Europe B.V.

Amsterdamseweg 37
NL-1422 AC UITHOORN, The Netherlands
www.kenwood-europe.com

Kenwood Electronics Italia S.p.A.

Via G. Sirtori 7/9
20129 Milano, Italy
www.kenwood.it

Kenwood Ibérica, S.A.

Bolivia, 239
08020 Barcelona, España
www.kenwood.es

with Clear Voice Sound

Virtual Front Surround

A Surround System based on an original Kenwood algorithm (VFS III) written for the
ADI (Analog Devices Incorporated) processor, which offers the experience and sensation
of spectacular surround sound with only two front speakers using a 2-way speaker system
and also incorporating an independent satellite speaker.

DSP

5.1

DVD

Vídeo

Virtual Surround effect giving the impression of sound

emanating from separate rear speaker enclosures.

Multichannel Sound

Front Loudspeakers

Exclusive 2-way loudspeakers that incorporate a third full range
satellite loudspeaker in the upper part. The frequency range of the
satellite loudspeaker and its direction towards the listener has been
calculated to reproduce clear sound effects, music or clear dialogue
depending on the selection Clear Voice Sound , “Movie” or “Music” mode.
If Virtual Front Surround has been selected, the upper satellite
loudspeakers reproduce the surround channels to create a natural and
realistic surround sound with impressive impact.

Acoustic Impression (Wide Control) adjustment.

Allows the listener to 'virtually' match the dimensions of the listening
room by expanding or reducing the sound field.

Clear Voice Sound

The center channel is one of the most
impor tant channels in good multi­channel reproduction. Processed sound
tracks with 5.1 or more channels dedicate
a special frequency range to the center
channel to make dialogue and voice
sound emanate from the center of the
screen in a stable and detailed way. With
the “Clear Voice Sound” technology for
clear and natural sound, the voices are
well reproduced, detailed and clear.

Music Mode

The Music Mode adapts the acoustic field to
reproduce music with great realism, atmosphere
and natural sound. This feature is applicable for
Virtual Front Surround as well as Clear Voice Sound.

4 VFS
4 CVS

28-bit Digital audio signal processor with

Sigma DSP technology from Analog Devices

Wide

Adjustable Acoustic Field

Sa tel li te spe ake r
used for the Center
or Surround channel
r e p r o d u c t i o n
depending on VFS or
Cle ar Voice Soun d
setting.

When Clear Voice Sound mode has been selected,
the Center speaker information is assigned to the
full-range satellite speaker, located in the upper
part of the loudspeaker enclosure. In that case the
combined Front and Surro und signals are
assigned to the 2-way speaker section.

Movie Mode

The Movie Mode adapts the acoustic field to a
dy na mi c s ur ro und so un d d ur ing m ovi e
reproduction offering sensational and realistic
surround effects. This feature is applicable for
Virtual Front Surround as well as Clear Voice Sound.

Auto Room EQ (Full Automatic Equalization to adapt to the listening environment)

The listening position is nearer to the left loudspeaker.
The right loudspeaker is located in a bookcase at a
higher position than the left one.

A Ca lib rat ion Mic rop hon e is
provi ded with the s ystem to
analyze frequency response, sound
pressure and time alignment, using
the Auto-Room-EQ functions via
the Sigma DSP processor.

After analysis the right loudspeaker virtually moves to
create optimal acoustic symmetry.

The ' Auto Room EQ' feature executes an automatic
equalization for the optimal balance of sound level,
timbre and phase at the listening position. After
locating the microphone at the listening position, the
processor analyzes the time that the signal takes from
each loudspeaker to the microphone. The delay time
between both loudspeakers serves to compensate and
to adjust the sound image. The compensation is carried
out to obtain optimal frequency characteristics in the
listening area. The equalization process compensates
for the losses in timbre due to absorption of produced
overtones and cancellation of reflections caused by
curtains or other elements of absorption in the room. It
also analyzes the reflections and bounces of the signal
due to reflecting walls, windows or other surfaces.
Through analysis of white noise transferred from the
loudspeakers to the microphone, the Sigma DSP
processor defines the suitable equalization curve to
achieve optimal sound quality at the listening
position.

Connectivity and Control

It is possible to listen to the Kenwood HD20GA7 portable hard
disc player via the AX-7 and operate it with the system remote
control if connected by a special cable (PNC-150) with 3.5mm
plug.

HD20GA7 (optional)
Portable hard disc player with
Clear Digital Amplifier and a
20Gb hard disc connected to the
AX-7 audio/video system by
PNC-150 cable.

M-AX7 4-channel Power Amplifier

The M-AX7 is the special power stage of the AX-7 incorporating 4
independent power broadband high fidelity amplifiers. The
amplifiers produce 25 Watts each and can be bridged to two
stereo channels of 50 Watt each.
The pre-amplifier C-AX7 sends the corresponding signals of

Virtual Front Surround or Clear Voice Sound to the M-AX7 which
amplifies them and passes the signals to each dedicated speaker unit. For stereo sound, the signals are
sent to the 2-way speaker part of the front loudspeakers. In stereo mode, the full range satellite
loudspeakers are not in use. In the AX-7 Kenwood uses a fully discrete amplifier section for clear and
powerful sonic performance.

2 way speaker system

in Stereo mode

L

180º

R

180º

Narrow 'Q'

D-BASS curve shape in Music Mode

1kHz 10kHz 20kHz80Hz

High Fidelity Speakers

In addition to the full range surround
speaker located in the upper part of the
Loudspeaker, used for dialogue and
effects, the speaker system incorporates a
2-way speaker system with a 12 cm cone
type woofer and a 2.5 cm balanced dome
tweeter. The speakers are magnetically
shielded to make setting next to the TV
possible. Thanks to the powerful amplifier,
the unique sound features, and the high
quality construction and sound of the
loudspeakers, the AX-7 turns out to be a
winner in the market.

Power amplifier circuit based on the BTL (Bridge-Tied Load) principle. In
the diagram the amplifiers are indicated as 4 triangles used in high
power stereo listening. Each channel uses a pair of bridged amplifiers in
contra phase to duplicate the power.

D-BASSIII System

The D-BASS III system accentuates the low frequency band in an
effective and suitable way according to the listening mode. The
“Q” (relation between the gain and the bandwidth) adapts in an
optimal way to music or film reproduction. The result is a warm
sound with tight bass in music mode where the bass is powerful
and with impact where needed during movie reproduction.

Wide 'Q'

D-BASS curve shape in Movie mode

60Hz 110Hz

1kHz 10kHz 20kHz80Hz