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The LFE-4 consists of a series of five high-pass filters (one each for the L, C, R, LS, LR channels) that route

high frequency information (above 80Hz) to their appropriate channel’s amplifier and speaker monitor. Each
channel is also routed through a matching 80Hz low-pass filter. This low frequency information is then routed to a
summing amplifier, which in turn sends this low frequency information, along with the LFE channel, to two dual
subwoofer outputs.

This is done for two reasons. First, small loudspeakers cannot reproduce information below 80Hz. At least,

not with any authority. This information is therefore summed together and redirected from the individual channels
to a loudspeaker that can reproduce this low frequency information with clarity and power – a subwoofer. With the
introduction of digital audio, it has become necessary for loudspeaker systems to be able to accurately reproduce
audio that has a bandwidth of 20Hz to 20kHz with wide dynamics. A satellite/subwoofer system is the best way to
accomplish this.

Secondly, most home theater receivers have some form of bass management in their processors. In order for

work done in the studio to translate properly, the mixer must hear his mix exactly the way it will ultimately be played
back. The LFE-4 together with a properly set-up and calibrated M&K monitor system allows the mixer to hear his
work with more accuracy than might otherwise be possible.

The LFE channel is a discrete channel created by the mixer to supplement the low frequency content of the mix.

The subwoofer channel is the summed low frequency content from the five main channels plus the LFE

channel. It is created by the processor in the encoder/decoder of your chosen format, or in this case, the LFE-4.

The LFE-4 correctly balances these channels so the mixer can accurately hear how the format processor will

affect his mix.

The goal is to be able to accurately monitor multi-channel audio with a bandwidth of 20Hz to 20kHz

containing extreme dynamics and have that audio translate accurately when played back on other systems.

A  properly set-up and calibrated M&K monitoring system with an LFE-4 will allow the mixer to make quick and

accurate decisions in a listening environment that he will find satisfying and enjoyable.

Bass Management Controller

6

Subwoofer

Left

Center

Right

Left Surround

Right Surround

LFE-4

  

Studio Bass Management Controller

 

 

RIGHT SUR

IN

RIGHT SUR

OUT

LEFT SUR

IN

LEFT SUR

OUT

RIGHT 

IN

RIGHT 

OUT

CENTER

IN

CENTER

OUT

LEFT

IN

LEFT

OUT

LFE IN

+0 dB

LFE IN
+10 dB

SUB OUT

1

SUB OUT

2

24 VAC

IN

CHASSIS

GND

SIGNAL

GND

FIGURE 1:

LFE-4 FRONT PANEL

FIGURE 2:

LFE-4 REAR PANEL

Содержание LFE-4

Страница 1: ...LFE 4 Miller Kreisel Sound Inc 9351 Deering Avenue Chatsworth CA 91311 5858 USA 818 701 7010 fax 818 701 0369 www mkprofessional com 2003 Miller Kreisel Sound Inc bass management operation manual...

Страница 2: ...FOR STEREO 8 7 CONNECTING FOR DOLBY DIGITAL 9 8 CONNECTING FOR DTS 10 9 CALIBRATING YOUR M K PROFESSIONAL SYSTEM 11 THE M K PROFESSIONAL TEST DISC 11 10 SPEAKER PLACEMENT 12 ITU R BS 775 1 RECOMMENDAT...

Страница 3: ...his product from the wall outlet and refer servicing to qualified personnel under the following conditions When the power supply cord or plug is damaged If liquid has been spilled or objects have fall...

Страница 4: ...DTS and other surround sound formats are faced with numerous challenges when trying to accurately monitor complex and dynamic material and determine how this material will sound in its intended playb...

Страница 5: ...e Bass management is equally suited to all formats from 2 channel stereo to 5 1 and beyond Indeed existing control rooms that are doing stereo 2 channel mixes especially with smaller nearfield monitor...

Страница 6: ...way it will ultimately be played back The LFE 4 together with a properly set up and calibrated M K monitor system allows the mixer to hear his work with more accuracy than might otherwise be possible...

Страница 7: ...of the mixer and power amplifiers through the XLR cables In order to minimize the grounding problems between the LFE 4 and equipment racks the internal audio signal ground can be separated from the ch...

Страница 8: ...ower amplifiers 5 Locate the external power supply for the LFE 4 and plug it into the 4 pin power connector on the back of the LFE 4 Secure it in place by turning the outer ring clockwise Plug the ext...

Страница 9: ...to plus and set the gain switch to the THX position 5 If you are using passive speakers with external amplifiers connect your speaker system to the power amplifiers 6 Locate the external power supply...

Страница 10: ...E 4 2 Connect the outputs of LFE 4 to the inputs of your power amplifiers or directly to your powered loudspeakers 3 Connect the mixer output assigned to the low frequency effects channel LFE to the 0...

Страница 11: ...el of 4dB with 20dB of headroom the maximum signal level from the source console etc can be 24dB Therefore at very high signal levels you can only add around 3dB of gain with the trim pots before the...

Страница 12: ...dation is based on placing the speakers at equal distances around a 2 5 meter circle with the height of each speaker at 1 2 meters The center speaker is placed directly in front of the listener with t...

Страница 13: ...eaking it is not a good idea to place the subwoofer directly in the center between the left and right speakers There s usually a null in this location which absorbs low frequencies rather than reinfor...

Страница 14: ...off your body and into the microphone Point the meter at the center speaker at about ear height Play track one of the test CD through the selected speaker and read the SPL Adjust the level to 85dB usi...

Страница 15: ...ut clipping level 27 dBu Gain Adjustment 12dB THD 1kHz 4 dBu 0 002 LFE Inputs Input impedance 20K ohm balanced Nominal input level 4 dBu Maximum input level 24 dBu Gain Adjustment 12dB Gain 10dB input...

Страница 16: ...LFE 4 manual PN 70360 7 08 2003 rev 1 pt qrk...

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