background image

7

AMPLIFICATION

MX SUBWOOFER SPEAKER AMPLIFIER POWER

To deliver Dolby® reference sound pressure 

levels (SPL) in the home cinema, three main 

design elements are critical to this outcome. 

The size of the room, the sensitivity of 

the speakers and the power output of the 

amplifiers.

The Series MX speakers and subwoofers 

have much higher sensitivity than typical hi-

fi  speakers.    This  means  that  the  amplifier 

power requirements are not excessive, even 

when installed in larger than average room 

sizes.
The MX-20 model, when used in a room 

of recommended size, can be powered 

successfully with a mid to top tier AV receiver. 

For larger rooms, a separate processor and 

power amplifier can be used to deliver extra 

power and will enhance the dynamics of the 

overall system.
The MX-30 system is best utilised in 

larger home cinemas and it is strongly 

recommended that they are driven with a 

separate  processor  and  power  amplifiers, 

rather than an all-in-one AV receiver. 

Separate  power  amplifiers  (including  ones 

with multiple channels) have the capability to 

deliver more current and therefore produce 

the dynamics and impact desired for a true 

cinematic experience.
As the subwoofers in the Series MX 

systems are passive (not self-powered), an 

independent  power  amplifier,  connected 

to the LFE channel(s) of the AV receiver/

processor, is required to power these units.

For best results with all MX series subwoofers, 

it is strongly suggested that a professional 

style  power  amplifier  is  employed  which 

has a selectable output limiter and high-

pass  filtering  options.  For  more  information 

regarding the configuration of these options 

see section 8.
Below are two graphs of the recommended 

amplifier power for each Series MX model in 

relation to room size. The minimum power 

line will provide cinema Dolby ATMOS® 

reference levels (105dB mains, 115dB LFE). 

Anything above this will allow additional 

headroom.

Room Depth (meters)

Amplifier 

Power

(Watts)

0

200

400

600

800

1000

1200

1400

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

MX-20 SUB

MX-30 SUB

Power handling 

(Program) limit

Min. recommended 

amplifer power

for 115 dB*

Summary of Contents for MX20

Page 1: ...SERIES MX INSTALLATION MANUAL ...

Page 2: ...x CONTENTS 2 INTRODUCTION 3 ROOM SUITABILITY 4 ACOUSTIC CONSIDERATIONS 5 ROOM SIZE 6 AMPLIFICATION 7 SYSTEM DIMENSIONS 8 SYSTEM POSITIONING 9 SCREEN WALL CONSTRUCTION 10 SUBWOOFER SETUP AND CONFIGURATION 12 WIRING 13 EQUALISATION 14 ...

Page 3: ...ry Both the infinite baffle wall and horn design technologies have been successfully combinedinourSeriesMXrangeofdedicated home cinema loudspeaker systems They are designed to be flush mounted into a false wall with an acoustically transparent screen placed over the front replicating the concept of a commercial cinema The Series MX modular systems feature the left centre and right screen loudspeak...

Page 4: ...r more details Due to the capability of higher SPL s than typical home entertainment systems it is recommended that allowances are made in the room design and construction for sound proofing or isolation Sound isolation is generally required to reduce or eliminate extraneous noises eg traffic noise from the street outside or internal plumbing entering the home cinema and disturbing the soft passag...

Page 5: ...d hard surfaces adjacent to the loudspeakers are not ideal Placing bass traps in appropriate positions within the home cinema can help to moderate bass response variations and will result in a more defined bass that is realistic particularly when listening to sound effects like gun shots or explosions It is highly recommended when designing a dedicated home cinema that you consult with an acoustic...

Page 6: ...lly considered if the desired Dolby reference level is to be achieved The Series MX loudspeaker systems have been designed to suit a range of room sizes to best deliver a true cinematic experience Taking into account the average number of seats each room size can accommodate the table below illustrates the ideal room size range for each Series MX screen speaker system Note The Series MX system sho...

Page 7: ...ne AV receiver Separate power amplifiers including ones with multiple channels have the capability to deliver more current and therefore produce the dynamics and impact desired for a true cinematic experience As the subwoofers in the Series MX systems are passive not self powered an independent power amplifier connected to the LFE channel s of the AV receiver processor is required to power these u...

Page 8: ...stereo separation The tables in Figures 2 4 show the overall dimensions along with recommended cavity size for each MX system Use these dimensions as a guide to match up to your selected screen size Room Screen wall Cavity for MX system Room Screen wall MX system Screen System System Width System Height System Depth Cavity Width Cavity Height Cavity Depth MX20 2210 mm 1220 mm 295 mm 2260 mm 1270 m...

Page 9: ...10 degrees of the listening axis of the speaker 500mm from base of speaker module For secondary viewing rows it is recommended to keep this angle within 20 degrees Care should also be taken to ensure the first row of viewers do not obstruct the sound path for viewers behind them Raising the platform height for subsequent rows can help to alleviate these issues System Spacer Width System Width Syst...

Page 10: ...and alone screen wall This particular technique is outlined under the section Isolated from rear wall Fixed directly to rear wall Using this construction method the shelf studwork supporting the MX modules is fixed securely with construction adhesive in conjunction with screws or nails to the baffle wall and also to the rear wall of the adjoining room 1 Fix the cavity frame to the rear wall Figure...

Page 11: ...s wall to the floor and the ceiling Figure 10 Where possible fill cavity with bulk insulation and then line the frame with plasterboard or other sheeting 2 Erect a frame for the screen wall and fix this to the floor ceiling and adjoining walls Figure 11 3 Fix noggins in between frames so that plasterboard or engineered timber board can be fixed Figure 12 At this point it is recommended to insulate...

Page 12: ...ono configuration It is strongly recommended to run separate cabling for all channels in the MX modular loudspeaker system back to the central amplifier rack to permit future flexibility with the wiring configuration Outputs 1 INDIVIDUAL CHANNEL Stereo Power amplifier 2 8 Ohm load on the amplifier Outputs 1 BRIDGED PARALLEL Stereo Power amplifier 2 4 Ohm load on the amplifier Output 1 PARALLEL Mon...

Page 13: ...e the use of high quality flexible multi stranded copper cables of suitable gauge are recommended for best performance For cable runs up to 10m in length a minimum 14AWG gauge cable should be specified for the main left main centre and main right loudspeakers and at least 12AWG cable for the subwoofers For longer cable runs consider using thicker cable If in doubt consult your Krix authorised deal...

Page 14: ...riven on program peaks the use of an effective soft limiter will protect the loudspeaker driver against clipping damage and will also reduce the incidence of adverse distortion when the amplifier is faced with signals in excess of its peak rating High pass filter The MX subwoofer can benefit from the use of an appropriately selected high pass filter By filtering out the subsonic frequencies the ov...

Page 15: ...hich can sound too bright forward and harsh in an average home cinema environment Some also pull too much energy out of the mid bass region resulting in a thin sounding system that lacks warmth and weight Listen for these issues when evaluating the results of an automated room correction system Manual Graphic Equalisation Manual graphic equalisation allows for a gentler equalisation curve to be ap...

Page 16: ...krix com Krix Loudspeakers Pty Ltd 14 Chapman Road Hackham SA 5163 Australia T 61 8 8384 3433 F 61 8 8384 3419 listen krix com Rev 01 ...

Reviews: