Advanced setup, Sub crossovers and bass management, Bi-amping – Cambridge Audio AZUR 551R User Manual

Page 26: Tone/sub/lfe configuration

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26

Advanced setup

For most users the basic four stage setup process (Page 14 onwards) should

be sufficient for normal use.
However the 551R also features many more advanced settings for users who

wish to further customise the settings and operation to personal preference.

Sub crossovers and bass management

As covered in the ‘551R Setup’ section the 551R performs bass

management for any speaker that is set to ‘Small’ in the OSD. This means

that bass for speakers that are unable to reproduce bass effectively is

instead routed to the subwoofer.

The crossover adjustments in the Speaker crossover menu are used to

determine the point as which this transition is made. In other words they set

the frequency below which bass is routed away from any ‘Small’ speakers

and into the Subwoofer channel. It should be understood that bass sent to

the subwoofer by bass management is different to bass encoded into the

surround-sound material as a dedicated Low Frequency Effects channel.
If the source material contains a separate LFE channel (ie DD or DTS

material) this is always routed to the subwoofer (if it is On) and is not affected

by the crossover setting. Some encoding types (Such as Dolby PLII/IIx and

Neo:6) do not actually have a LFE channel.
The default setting for all bass management crossovers is 80Hz and is a

good global starting point. If you do not wish to make any adjustments simply

leave all crossovers at this default setting.
Note: These settings are actually only used for speakers that have been set

to Small in the Speaker Configuration Menu.
For advanced users it is however possible to adjust the speaker crossovers

used for any speakers set as ‘Small’ independently to allow for the fact that

you may wish to direct bass away from front floorstanding speakers (and to

the Subwoofer) at perhaps 50Hz but away from Surround Left and Rights at

perhaps 100Hz. If you wish to make these adjustments it is best to consult

your loudspeaker manufacturers documentation or contact your dealer to

determine the frequency response of your system and where each speaker

types bass response starts to tail off (often called the 3dB or 6dB roll

off/cutoff point). This would be approximately the point the corresponding

crossover should be set to.

Bi-amping

If you a running a 5.1 (or less) speaker setup only the 551R allows for bi-

amping of the front left and right channels. It will be seen in the Speaker

Configuration menu that with the Decode mode set as 5.1 a Bi-amp On/Off

item appears.

When selected, the 551R sends the front left and right signals to the SBL and

SBR outputs as well.
In conjunction with bi-wireable/bi-ampable speakers this allows you to use

two runs of speaker cable to each speaker with a dedicated amplifier

channel for the bass and treble drivers of each speaker which can slightly

increase the sound quality.

See diagram below of a bi-amped system (only front left and right speakers

shown).
Note: Bi-wire links must be removed on the speaker’s terminals.

Tone/Sub/LFE configuration

Select the ‘Tone/Sub/LFE’ menu:

The Bass response can be adjusted +/- 10dB @ 100Hz (shelving). The Treble

response can be adjusted +/-10dB @ 10kHz (shelving). The “Tone” icon will

light up on the display if these controls are adjusted away from 0dB (flat). The

Subwoofer crossover point can also be adjusted from 40 to 150Hz in 10Hz

steps and also to 200Hz.
The 551R incorporates a couple of advanced Bass Management features.

The overall Sub Level for DD/DTS modes, PLII/x/Neo:6 modes and Stereo +

Sub mode can be set to different levels. This can be useful if you prefer to

have a high level of Sub operation whilst watching movies but a lower level

for music playback. The three levels are simply adjusted by up to +/-10dB in

the OSD. The second feature is that the way Bass Management is applied

can be changed.
In normal operation (Bass Augment Off) if the Front speakers are set to

‘Small’ (in the ‘Speaker Config’ menu) their bass is re-directed by high-pass

filtering the Fronts and sending that bass to the Sub channel (i.e. bass is

removed from the Fronts and sent to the Sub). If they are set to ‘Large’ no

filtering takes place and no bass is sent from them to the Sub channel.
However with the Bass Augment function On and the Front speakers set to

‘Large’, bass from the Front Left and Right is now sent to the Sub channel

without any filtering of the Front Left and Right taking place (i.e. these

channels remain full range). In other words, the bass in the Sub channel is

augmented by extra bass from the Front Left and Right channels. If the Front

Left and Right are set ‘Small’, Bass Augment has no effect and operation is

the same as for Bass Augment Off.
Bass Augment can be On or Off separately for DD/DTS or PLII/IIx/Neo:6

operation.
There is no Bass Augment function for Stereo + Sub mode because in this

mode if the Front speakers are set to ‘Large’ they will actually always be

unfiltered.
Bass Augment can be a useful function with PLII/IIx and Neo:6 material

because these encoding types do not include an LFE Channel. This would

normally mean that if all the speakers in your setup were set to ‘Large’, the

subwoofer would in fact be inactive (as no bass has been re-directed plus

there is no LFE channel). If it is desired to have the subwoofer running with

all Large Speakers and these encoding types, enable Bass Augment for

PLII/Neo6 and then set the Crossover points and levels by ear. A Sub channel

will now be created from the Front Left and Right channels without filtering

them. As with all adjustments it is a good idea to experiment to determine

what works best with your particular setup.
Note: These adjustments work in all digitally processed Stereo or Surround

modes but not in Analogue Stereo Direct or 7.1 Direct modes.
The LFE channel (for DD / DTS material) can also be trimmed by up to 10dB

in 1dB steps useful for late night listening or other situations where it might

be desired to reduce the low frequency effect level perhaps temporarily.

Speaker Crossover Menu

Front L/R

:

Centre

:

Surr. L/R

:

Surr. LB/RB

:

Return : [OSD]

80Hz
80Hz
80Hz
80Hz

Speaker Config Menu

Decode Mode

:

Front L/R

:

Centre

:

Surr. L/R

:


Subwoofer

:

Biamp

:

Return : [OSD]

5.1

Large
Small
Small

Yes

No

Front
Right

Front

Left

Surround

Left

Surround

Back Left/

Surround Back

Centre

Surround

Right

Surround

Back Right

Speaker Impedance 4-8 Ohms

7.1

7.1

6.1

6.1

5.1

5.1

Front
Right

Front

Left

Surround

Back Left/

Surround Back

Surround

Back Right

Speaker Impedance 4-8 Ohms

7.1

6.1

5.1

Tone/Sub/LFE Menu

Bass
Treble
LFE Trim
Dolby Digital/DTS Sub Trim

:

Dolby Digital/DTS Bass Aug

:

Dolby PLIIx/NEO Sub Trim

:

Dolby PLIIx/NEO Bass Aug

:

Stereo+Sub Trim

:

Return : [OSD]

0dB
0dB
0dB
0dB
Off
0dB
Off
0dB

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