TC Electronic DB4 MKII User Manual

English Manual

Last update: 2013-10-21

DB4 / DB8 MKII Algorithms

About this manual 1

Introduction 3

DYNAMICS PROCESSING 5

MDX 5.1 7

Multiband5.1 17

EQ + DELAY 25

EQ/Delay8 27

FORMAT CONVERSION 31

DMix 33

Downconvert 5.1 41

Unwrap HD 47

UpCon HD and UpCon Plus 53

LOUDNESS CORRECTION 61

ALC 5 .1 63

ALC 6 69

ATX / DX 71

LOUDNESS RADAR METER 79

LM6 81

English Manual a

About this manual

This manual will help you learn understanding and operating your TC product.

This manual is available in print and as a PDF download from the TC Electronic website. The most current version is always from the TC Electronic website.

To get the most from this manual, please read it from start to finish, or you may miss important information.

To download the most current version of this manual, visit

http://www.tcelectronic.com/support/manuals/

DB6 algorithm and operation manuals

The document you are now reading – the DB4/

DB8 MKII Algorithms manual – contains infor-

mation about the signal processing and metering features performed by DB6.

For information about setup, general use, routing and presets, please consult the DB4/DB8 MKII

Setup & Operation manual, which is a separate

document.

Up-to-date versions of both documents can be downloaded from the TC Electronic website.

English Manual 1

About this manual

2 DB4 / DB8 MKII Algorithm s

Introduction

– Surround Sound Forum Recommended Prac-

Introduction

The DB4 / DB8 MKII Algorithms Manual contains information about the processing performed by DB4/DB8 MKII. For information about setup, general use, routing and presets, please consult the DB4/DB8 MKII Operations Manual.

DB4 and DB8 MKII are capable of running multiple, independent processors simultaneously. One such processor is called an “ Eng ine”. Engines may be routed to deal with independent audio streams, or combined, for instance, to condition one input stream to different outputs, so-called trickle-down processing. Use the Routing page to define how engines are routed, and to assign physical inputs and outputs.

For each Engine, you may recall a different “algorithm”. An algorithm is a specific processor, for instance up-conversion or 5.1 loudness correction. Most of this manual describes in detail the different algorithms you may recall into an engine of DB4 and DB8.

Engine presets are compatible between DB4 MKII and DB8 MKII. MKII units also read Engine presets from original DB4 and DB8. Finally, presets based on the algorithm “DTX” are compatible with the stereo processor, DB2.

tice SSF-02/1-E-2 (3-5-99), Multichannel Recording Format, Parameters for Programme Interchange and Archiving, Alignment of Reproduction Equipment.

Grouping the Inputs/Outputs this way ensures optimal flexibility for further external processing and archiving, when working on setups following the above mentioned standards.

It is, however, worth noticing that total routingflexibility of physical Inputs/Outputs to Engine Inputs/Outputs is available on DB8/DB4 via the Routing page.

Metering in the engine edit pages

For logical channel metering in the various surround algorithms, the meters on the Engine Edit pages are displayed from left to right in the following order.

– Left – Center – Right – Left Surround – Right Surround – LFE

Channel distribution in surround algorithms

To best comply with the channel allocation used by most digital AES format equipment, the Input/ Output channels on surround algorithms are allocated as follows:

1 Left 2 Right 3 Center 4 LFE 5 Left Surround 6 Right Surround

These channel allocations comply with the following standards:

– ITU Recommendation ITU-R BR.1384, Param-

eters for International Exchange of Multichannel Sound Recordings, 1998

– SMPTE 320 M-1999, for Television Channel

Assignments and Levels on Multichannel Audio Media

Meters on engine edit pages

We believe that by displaying the meters on the Engine Edit pages in the same order as your speakers are physically placed, the most intuitive metering of channel-levels is achieved.

English Manual 3

Introduction

4 DB4 / DB8 MKII Algorithm s

Introduction

Dynamics processing

English Manual 5

Introduction

6 DB4 / DB8 MKII Algorithm s

MDX  5.1

Dynamic Range of

MDX  5.1

Introduction

MDX5.1 is a high resolution dynamic range processor for multichannel signals. It may also be used to process for mono or stereo, thereby making changes or adjustments unnecessary.

Its combination of low level lift, multi-band structure, output limiting and extensive controls offers the most sophisticated dynamic range translation capabilities in the professional audio industry today. Not surprisingly, MDX5.1 has become the standard for dynamic range control in film and music mastering.

Dynamic range tolerance (DRT) at the consumer

The Dynamic Range Tolerance map, Fig 1, illustrates the dynamic range targets for various listening environments. It is therefore a practical tool for optimizing listener pleasure in digital broadcast.

According to recent studies, listeners typically object against too wide dynamic range much more than when the range is too restricted. Lack of speech intelligibility is the second worst offender, and often the cause for requesting more dynamic range limitation. Against the hopes of audio aficionados, as more people are listening through headphones (iPods and other personal entertainment systems), the DRT trend is therefore currently moving towards more dynamic range restriction in broadcast.

Broadcast Material

Today, program material for TV broadcast is generally aimed at a listener in the Living Room or Kitchen region, see Fig 1. This kind of material should be thought of as having a normal broadcast dynamic range signature.

Commercials, promos and consumer CDs typically have a more restricted dynamic range, and therefore appear loud on TV, where normalization is based only on peak content. This kind of material should be thought of as having a hot dynamic range signature.

On the opposite side we have film production, aimed at a completely different listening scenario, where much softer and much louder level than the average can be reproduced and heard. Production for wide dynamic range listening can also include classical or acoustic music. All material of such nature should be thought of as having a soft dynamic range signature.

Music and entertainment radio is typically aimed at Car listening, so the dynamic range signature is generally hot. The only type of radio with a wider dynamic range typically carries classical music, drama and low key, talk based programming.

To summarize, broadcast material is produced in a way that fits the listening conditions of a wide majority of consumers in the best possible way. The most dramatic difference between program material and consumer requirements concerns feature film. To have a feature film align with domestic listening conditions without loosing too much detail, or distorting the loud parts, low level may need to be brought up by 12 to 20dB, and the headroom restricted by 12 to 16dB.

Processing for digital broadcast

Digital broadcast has the potential to carry more formats at a wider dynamic range than analog. For example, feature films can be presented more like they were mixed and edited, with fewer compromises on the picture as well as on the audio side. However, even for HDTV, audio still needs optimization for a presentation environment different than a cinema, like the picture still needs color space, rate and resolution correc-

Fig 1. DRT map for consumers under different listening situations.

English Manual 7

tions.

MDX  5.1

The jumping level problem from analog TV will become bigger if stations transmit feature films with a less suitable dynamic range than today, because film fall way outside the Dynamic Range Tolerance of the average consumer under her domestic listening conditions.

Consequently, dynamic range restriction must take place either at the station, or inside the consumer’s receiving device.

Dynamic range translation should deal with both overly soft and overly loud parts. Ideally, the perfect re-mapping should happen at the receiving end to accommodate a wide range of listening conditions. Metadata in conjunction with, for instance, Dolby AC3, provides some of these capabilities. However, even if the consumer knows how to adjust the dynamic range of a film to her current listening conditions, the optimum dynamics treatment unfortunately far exceeds the capabilities of an AC3 decoder. The dynamic range control in the codec is acceptable for cut and boost ranges of 4 to 6dB, but preparing a feature film for broadcast needs considerably more than this.

If such a large correction is left only to the AC3decoder, the wide-band gain changes can be quite audible. Film and music dynamic range correction requires a multiband structure so listeners don’t sacrifice speech intelligibility, or get subjected to the spectral intermodulation of a crude, wideband range controller.

MDX  5.1

The MDX 5.1 processor available in DB4 and DB8 is capable of bringing up low level detail, rather than boosting everything, and then having to limit the transients afterwards, see Fig 2. Low level lift can even be applied to specific channels selectively in one, two or three frequency bands.

Fig 2. DXP processing vs. traditional Compression and Limiting. Note how already loud signals are unnecessarily affected when relying on limiting and clipping.

Applications

MDX5.1 is well suited for dynamic range control of any kind of broadcast material. Film, sports, music or game shows. It may be applied during ingest, transmission – or both places.

With suitable parameter settings, high resolution audio can pass through more than one hundred MDX 5.1 processors without perceivable degradation of quality The ingenious topology of DB4 and DB8 allows for the processing to be performed instantly (the latency is below 0.5 ms, equivalent to moving a microphone approximately 16 cm or 6 inches), making re-alignment of audio and picture a non-issue.

Processing strategies

The major part of dynamic range translation should be done at the station, leaving only smaller corrections to be performed at the consumer. This ensures competitive audio with regards to consistency, quality and speech intelligibility, and prevents asking more from the AC3decoder than it can deliver in a civilized manner.

8 DB4 / DB8 MKII Algorithm s

MDX  5.1

Tip: Use the Input Gains as overload protected level trims in a critical realtime system, such as broadcast, OB or live music.

On the Link pages, the 5 Main channels (L, C, R, SL and SR) can be linked in numerous ways. The concept is to assign a channel to a Sidechain. If all channels are assigned to the same Sidechain, processing is identical on all of them. If a channel is assigned to a different Sidechain, processing on that channel may be different from processing on the other channels.

The DXP pages reveal separate controls for Sidechain 1 to 3 plus LFE. This enables, for in-

Fig 3. Example of dynamic range re-mapping: From Home Theatre/DVD to Living Room listening conditions (Fig 1).

stance, different settings for the Center or Surround channels, where speech intelligibility or low level ambience tend to get lost. Like when a feature film is re-purposed for broadcast or DVD

under domestic listening conditions. Fig 3 and Fig 4 show rational transfer characteristics complying with the DRT of the consumer, without affecting levels when they are already on target.

If it is required to process more audio channels

than 5.1, Engines can be run in parallel to cater

for 6.1, 7.1, 10.2, 12.2 or even higher number for-

mats. Parallel Engines attain perfect phase con-

servation and resolution, and do not compro-

mise audio in any way.

Fig 4. Example of dynamic range re-mapping: From Home Theatre/DVD to Living Room listening conditions (Fig 1).

Basic Operation

On the Main page, MDX 5.1 offer Input Gain controls for the Main Channels and for the LFE Channel. This enables positive and negative gain normalization to be performed in the 48 bit domain prior to low level processing and output limiting. These gain controls therefore operate in a safe location, well protected from generating output overloads.

MDX 5.1 features 48 bit fixed point processing

throughout. Split and reconstruction filters are

phase linear when the algorithm is used in mul-

tiband modes.

English Manual 9

MDX  5.1

Fig 5. MDX5.1 Level Diagram for different Steer and Threshold settings. “Defeat Threshold” relates to DXP Threshold which relates to “Ref Level”. “Limit Threshold” only relates to Digital Full Scale output level. The Ref Level parameter on the Main page sets the unity gain point for all channels (unless gain offsets are applied), see Fig 5.

The Thresholds on the DXP pages are relative to Ref Level, so in this particular drawing, Ref Level is set at -12dBFS, while most DXP Thresholds are set at -16 dB. If you invoke the Defeat Threshold, gain reverts to unity for “below radar” input levels. Defeat Threshold is relative to DXP Threshold. In the drawing, the Defeat Threshold is set at -20dB.

Note, that the lower the DXP Threshold, or the higher a Steer setting, the more low level boost is applied. The low level boost can be different in different channels, and even in different frequency bands.

Also observe that the Limiter threshold setting is not relative to Ref Level, but always referenced to output full scale.

frequency band is currently attenuated by 2dB,

while the Mid and Hi bands are at 0dB gain.

Fig 6.

Example of MDX5.1 Gain Meter. The me-

ter shows max low level gain and spectral re-

sponse, plus current gain and spectral re-

sponse. In the example, the Low band is cur-

rently attenuated by 2dB, while Mid and Hi

bands are at unity gain (0dB).

Adjustment Tips

The easiest way to specify the yellow area of Fig

1 is to set an appropriate difference between the

Ref Level parameter and the Limit Threshold.

Wide dynamic range material for a high reso-

lution delivery might be broadcast with a sub-

stantial difference between the two, for instance

15dB or more.

If the audio bandwidth is low, and the listener

environment presumably noisy, the difference

between Reference and Limit Thresholds should

smaller. For heavily data reduced multi-channel

broadcast, best results are typically obtained

with a 6 to 10dB difference.

When significant data reduction is to be used,

Reading the Gain Meters

Gain meters in indicate absolute gain. The upper segments of a meter gives an indication of the boost and frequency response applied to low level signals, while the lower segments of a meter gives an indication of the current (dynamic) gain and frequency response, see Fig 6.

In this example, low level signals are subject to a 5dB boost in the Low and Hi band. The Low

10 DB4 / DB8 MKII Algorithm s

also be careful not to allow peaks going all the

way to 0dBFS. Consider bringing down the Limit

Threshold between 1 and 4dB. Judge the qual-

ity of loud, spacious material passing through

MDX 5.1 plus data reduction plus decoding,

while listening to the output of the data reduc-

tion decoder. Pay special attention to transient

distortion, and if the sound image collapses at

high levels.

MDX  5.1

In general, and especially for feature film remapping in ingest, start by processing all channels by the same amount. This can be achieved by assigning all channels to Sidechain 1, or by using different sidechains with identical settings. Then conclude if speech in the center channel, ambience in the surrounds or activity in the LFE channel etc. needs special attention and processing.

When it is indicated to bring up dialog level and speech intelligibility, you may end up with something like the level diagram presented in Fig 5. This particular transfer curve has been used successfully at stations with special attention to speech intelligibility.

Compare against the DRT chart, fig 1, and note how the Center channel is given an extra low level advantage compared to the four lateral channels, without the basic mix balance being generally changed. This curve ensures that dialog can still be heard when the words could otherwise be lost to listening room noise. The lateral channels are linked two and two, or all in one group. Presets of this nature is located in Engine Factory Bank F2 (“Loudness, Multichannel”), decade 3, preset 0 to 3 (“Film Curve C3 – C12”).

Tip: To produce multiple ingest versions from the

same source material, start doing the one for the

highest resolution.

Lower resolution versions can be achieved by

adjusting the Limit Threshold to comply with the

alternative delivery format, then adjusting the Ref

Level to optimize results under the new, restrict-

ed dynamic range conditions. In many cases, no

further tweaking will be needed.

Please be advised that some reproduction sys-

tems distort when downmixing hot multichannel

signals to stereo. Therefore, don’t abuse multi-

channel formats by bringing all channels close to

0dBFS at the same time, except for short dura-

tion, loud incidents.

Tip: When making the final transmission adjust-

ments, try changing the Ref Level parameter up

and down a few dB. This is an efficient way of

trimming hundreds of parameters in MDX5.1 at

the same time. Listen to the result, while decid-

ing what is the optimum setting for that particular

broadcast platform.

MDX5.1 Factory Preset

Nomenclature

Engine presets based on the MDX5.1 algorithm

is located in Factory Bank F2 (“Loudness, Multi-

channel”), decade 2 and 3. Presets are labelled

Film Curve A-D plus a number.

Fig 7. Example of multiband dynamic range re-mapping of a 5.1 feature film to domestic listening conditions. Preset names: “Film Curve C3-C12”. Black curve: Center channel. Orange curve: L, R, Ls, Rs.

Film Curve A presets add the same amount of

boost to all 5.1 channels. At Reference Level, the

gain is unity (0 dB). At low level (- 35dBFS and

below), the number after the “A” in the preset title

indicates the amount of low level boost. For ex-

ample, the preset “Film Curve A6” adds 6dB of

low level gain to all 5.1 channels.

Film Curve C presets add the same amount of

boost to all 5.1 channels, but the max gain is

achieved earlier for the Center channel than for

the rest (like in Fig 5). At Reference Level, the

gain is unity (0 dB). At low level (- 35dBFS and

below), the number after the “C” in the preset

title indicates the amount of low level boost. For

example, the preset “Film Curve C6” adds 6dB

of low level gain to all 5.1 channels.

Film Curve D presets add 3dB more gain to the

Center channel than to the other channels. Max

gain is also achieved earlier for the Center chan-

nel than for the rest (like in Fig 5). At Reference

English Manual 11

MDX  5.1

Level, the gain is +3dB for the Center channel, but unity (0 dB) for the others. At low level (35dBFS and below), the number after the “D” in the preset title indicates the amount of low level boost. For example, the preset “Film Curve D6” adds 9dB of low level gain to the Center channel, but 6dB of low level gain to the rest of the channels.

MDX5.1 algorithm – main page

The dB steps between RMS and Peak are the

dBs needed for a peak-value to override RMS

measurement.

DXP Defeat Level

Range: Off, -30dB to -3dB

MDX 5.1 may remove low level gain below the

threshold set with this parameter to avoid having

irrelevant sources (e.g. background noise) be-

come audible. Low level gain is not revoked if the

DXP Defeat Level parameter is set to Off.

The Defeat threshold is relative to DXP Band

Thresholds, which are relative to Reference Lev-

el.

Example: If Reference Level is set at -20dBFS,

Band Thresholds at -15 dB, and DXP Defeat

at -22 dB, low level boost starts rolling off at

-47dBFS. See example at page 18.

MDX5.1 algorithm – main page

Input Gain Normalizer for Main and LFE channels

Range: -18dB to +18dB

As we process in a 48 bit domain both positive and negative gain normalization can be performed prior to low level processing and output limiting. These gain controls therefore operate in a safe location, well protected from generating output overloads.

Reference Level

Range: -24dBFS to 0dBFS in 0.5dB steps

This parameter sets the reference level in the algorithm. The reference level is the level at which the Threshold parameters will start operating when set to 0dB. E.g. if the Reference Level is set to -18 dBFS (often referred to as 0 dBu), a Threshold setting at -4dB, will cause the Compressor to start operating at -22dBFS.

Crest

Range: Peak, 6dB, 10dB, 12dB, 14dB, 16dB, 20dB, 24dB, RMS

Select compression method between RMS and PEAK.

Nominal Delay

Range: 0 to 15 ms

0 to 2 ms in 0.1 ms steps

2 ms to 15 ms in 0.5 ms steps

Adds a delay to the passing audio in order to

have regulation start “ahead of time”. Using this

control can reduce the need for peak limiting,

and prevent dynamic distortion from being add-

ed to sensitive material.

Note that look-ahead is scaled with Attack per

band.

Example: If a 5 ms Nominal Delay has been set,

and Attack is 10 ms on the low band and 1 ms

on the high band, audio is delayed 5 ms on all

bands (phase linear topology). However, to pre-

vent pre-transient holes from being generated,

Attack regulation starts 5 ms “ahead of time” on

the low band, but only a little more than 1 ms

“ahead of time” on the high band.

Hi/Lo Crossovers

MDX5.1 uses a phase linear, 48 bit split and re-

combination filter structure in order to enable dif-

ferent low level detail boost at different frequen-

cies. This counteracts spectral inter-modulation,

and is useful in order to preserve speech intel-

ligibility. Two-band or wide-band DXP process-

ing can be accomplished by setting one or both

crossover points to Off.

12 DB4 / DB8 MKII Algorith ms

MDX  5.1

MDX5.1 algorithm – link control page

The Sidechain assignment possibilities in the MDX5.1 are very comprehensive. Carefully selecting which channels should be controlled by which Sidechains, is just as essential as dialing in the correct Threshold and Ratio values.

keeping the channel time-aligned to the other

(processed) channels.

Sidechain Control

Range – for the five main channels:

– Unprocessed

– Side Chain 1

– Side Chain 2

– Side Chain 3

Range – for the LFE channel:

– Unprocessed

– LFE

MDX5.1 algorithm – link feed page

It is possible to freely select any or none of three Sidechains to control each of the main-channels. This also gives you the option of grouping the channels. In addition to this, the LFE channel has its own Sidechain control. This enables e.g. setting up two Multiband 5.1 algorithms in serial setup, while having six individual Sidechains available, enabling fully individual Sidechain controls of all channels.

At the Feed page it is possible to make additional Sidechain link Inputs, for e.g. having the Centerchannel contributing to the Sidechain Inputs of the two Front channels, to create a more coherent sound from the front-channels.

The illustration above reflects the Processing parameter set to MDX5.1 in Normal mode.

Basic operation

At the Setup/Control page it is possible to decide which Sidechains should control which channels. Select any of three Sidechains to be assigned to any of the five Main-channels. You can also chose to pass the channels unprocessed through the algorithm. The LFE channel can be assigned to its own separate Sidechain, or be left unprocessed.

Setting a channel to unprocessed will preserve the processing delay through the algorithm,

MDX5.1 algorithm – link feed page

The Setup/SC Feed page holds parameters

specifying which Input channels should feed the

three Sidechains.

Normal

Range: Off, On

When this parameter is set to “On” the Input

channels selected to be controlled by the re-

spective sidechain will also input to the side-

chain.

Add 1, Add 2 and Add 3

Range: Off, LFr Max, RFr Max, Cnt Max, LSr

Max, RSr Max, Xt Max, LFr Sum, RFr Sum,

Cnt Sum, LSr Sum, RSr Sum, Xt Sum.

These parameters enable extra channels to be

assigned to the respective Sidechain Input. The

extra sidechain Input channels will not be pro-

cessed by the sidechain.

English Manual 13

MDX  5.1

The Sum settings will add the Input to the sidechain, whereas the Max settings only will contribute to the sidechain if the level exceeds the other Input channel levels.

MDX5.1 algorithm – DXP page

Sidechain Fader Groups

The DXP pages reveal separate controls for Sidechain 1 to 3 plus LFE. This allows for different settings for the Center or Surround channels, where speech intelligibility or low level ambience tend to get lost, like when a feature film is repurposed for broadcast or DVD under domestic listening conditions.

If it is required to process more audio channels than 5.1, Engines can be run in parallel to cater for 6.1, 7.1, 10.2, 12.2 or even higher number formats. Parallel Engines attain perfect phase conservation and resolution, and do not compromise audio in any way.

MDX5.1 algorithm – Limiter – soft clip page

Softclip

Full Range Softclip

Range: -6dB to Off

Softclipper Threshold setting after the Compres-

sor for the five multiband channels. Threshold

is always relative to 0dBFS (Not the Reference

Level).

LFE Softclip

Range: -6dB to Off

Softclipper Threshold setting for the LFE chan-

ne l only.

MDX5.1 algorithm –

Limiter – main page

MDX5.1 algorithm – Limiter – soft clip page

The Limiter page is divided into three Sub-pages. One covering the Softclip section, one Main Limiter and one for the LFE Limiter.

Generic parameters in this algorithm:

Meter Zoom

Press Meter Zoom to decrease meter range and have a more accurate metering.

Bypass Limiter

Press to Bypass the Limiter section.

14 DB4 / DB 8 MKII Algori thms

MDX5.1 algorithm – Limiter – main page

MDX  5.1

Threshold

Range: -12dB to Off

-6 to 0dB in 0.1dB increments

-12 to -6 in 0.5dB increments

Brickwall limiter for the five channels. Threshold is always relative to 0dBFS. LED on each Output meter indicates when Limiter is active.

Release

Range: 0.01 to 1.00 seconds

Release time for the Limiter.

Ceiling

Range: -0.10dB to 0dB

Fine-tuning parameter setting the Ceiling for the Limite r.

The Ceiling parameter prevents the Output signal from exceeding the adjusted Limiter Threshold. It can be used to “hide” overloads to downstream equipment, but it does not remove the distortion associated with an overload.

LFE Limiter

Threshold

Range:

-12 to +3dB

-6 to + 3 in 0.1dB increments

-12 to -6 in 0.5dB increments

Brickwall limiter for the LFE channel. Threshold is always relative to 0dBFS. LED on each Output meter indicates when the Limiter is active.

Release

Range: 0.01 to 1.00 seconds

Release time for the Limiter.

Ceiling

Range: 0 to -0.10dB in 0.01dB steps.

Fine-tuning parameter setting the Ceiling for the Limite r.

English Manual 15

MDX  5.1

16 DB4 / DB8 MKII Algorithm s

Mul t i b and 5 .1

Multiband5.1 algorithm

Multiband5.1

The inputs and outputs of this algorithm are distributed as follows:

Input Output

L R R

C C

LFE LFE

SL SL SR SR

E1 E2 E3 E4

– main page

Multiband5.1 algorithm – main page

Introduction

The Multiband 5.1 algorithm is a multi-channel, multi-band optimizer, with Limiters and extensive possibilities to assign channels to multiple sidechains.

Four-band dynamics are available for 5.1 processing.

At the Main page, you have access to the general

set-up parameters for the Expander and Com-

pressor sections.

Meters are shown for all seven Inputs and six

Outputs at the right of the display.

With the Multiband5.1 it is possible to integrate dynamics processing for 5.1 applications offering features, which are not possible if using multiple stereo dynamic processors.

Multiband5.1 processor contains:

– 5 channels of three band expansion and com-

pression – Full-range brickwall limiter on all Outputs – 1 channel of full range expansion, compres-

sion and limiting for the LFE (Sub) channel – 3 Sidechains for the five main channels, that

can be assigned in flexible ways – 1 extra Input channel that can be used for ex-

ternal Side Chain Input.

Band Xover Frequencies

Lo Xover

Range: Off to 16 kHz

Sets the Cross-over frequency between the Loand the Mid- Expander and Compressor bands for the five main channels (LFr, RFr, Cnt, LSr, RSr).

The two Cross-over points are not allowed to cross each other. Therefore the parameter range can be less than 16 kHz if the Hi Xover parameter is set below 16 kHz.

Hi Xover

Range: Off to 16 kHz

Sets the Cross-over frequency between the Midand the Hi- Expander and Compressor bands for the five main channels (LFr, RFr, Cnt, LSr, RSr).

The two cross-over points are not allowed to cross each other. Therefore the parameter range can be less than going down to Off, if the Lo Xover parameter is set above the Off position.

English Manual 17

Mul t i b and 5 .1

Performance Settings

Crest

Range:

Peak, 6dB, 10dB, 12dB, 14dB, 16dB, 20dB, 24dB, RMS

Select compression method between RMS and PEAK.

The dB steps between RMS and Peak are the dBs needed for a peak-value to override RMS measurement.

Nominal Delay

Range: 0 to 15 ms

(<2 ms in 0.1 ms steps. >2 ms in 0.5 ms steps)

Sets the nominal Delay of the signal compared to the

Sidechain signal. This is also known as “Look ahead Delay”, enabling the Compressor section to become more responsive to the incoming signal.

Automatic Make Up Gain

Range: Off/On

Switches the Automatic Make-up gain On or Off. As using compression is a reduction of dynamic range in the signal a compensation for this loss of gain on the Output side is possible. Use the Auto Make Up gain to achieve this.

Reference Level

Range: -24dBFS to 0dBFS in 0.5dB steps

Multiband5.1 algorithm – side chain control page

The sidechain assignment possibilities in the Multiband5.1 are very comprehensive. Carefully selecting which channels should be controlled by which Sidechains, is just as essential as dialing in the correct Threshold and Ratio values.

It is possible to freely select any or none of three Sidechains to control each of the main-channels. This also gives you the option of grouping the channels. In addition to this, the LFE channel has its own Sidechain control. This enables e.g. setting up two Multiband 5.1 algorithms in serial setup, while having six individual Sidechains available, enabling fully individual Sidechain controls of all channels.

The illustration above reflects the Processing parameter set to Multiband5.1 in Normal mode.

Basic operation

18 DB4 / DB8 MKII Algorith ms

Mul t i b and 5 .1

Setting a channel to unprocessed will preserve the processing delay through the algorithm, keeping the channel time-aligned to the other (processed) channels.

Side Chain Control

Range – for the five main channels:

– Unprocessed – Side Chain 1 – Side Chain 2 – Side Chain 3

Range – for the LFE channel:

– Unprocessed – LFE

Multiband5.1 algorithm – side chain feed page

The Sum settings will add the Input to the sidechain, whereas the Max settings only will contribute to the sidechain if the level exceeds the other Input channel levels.

Multiband5.1 algorithm – Expander – main page

Multiband5.1 algorithm – side chain feed page

The side chain feed page Setup/SC Feed page holds parameters specifying which Input channels should feed the three side chains.

Normal

Range: Off, On

When this parameter is set to “On” the Input channels selected to be controlled by the respective sidechain will also Input to the sidechain.

Add 1, Add 2 and Add 3

Range: Off, LFr Max, RFr Max, Cnt Max, LSr Max, RSr Max, Xt Max, LFr Sum, RFr Sum, Cnt Sum, LSr Sum, RSr Sum, Xt Sum.

These parameters enable extra channels to be assigned to the respective Sidechain Input. The extra Sidechain Input channels will not be processed by the sidechain.

Pressing Threshold, Range, Ratio, Attack and Release keys will immediately assign Lo, Mid, Hi, All and LFE values for these parameters to Faders 1 to 4.

Be aware that the range of the All parameter is relative to the settings of the same parameters in the Compressor section.

Threshold

Range: -50dB to 0dB (in 0.5dB steps)

When the signal drops below the set Threshold point the Expander starts to generate downward expansion.

Range

Range: -40dB to 0dB in 0.5dB steps

Sets the maximum range of the expansion.

Ratio

Range: Off to Infinity

Sets the Expansion Ratio below the Threshold point.

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Mul t i b and 5 .1

Release

Range: 20 ms to 7 sec.

Sets the time it takes for the Expander to release its attenuation of the signal when the signal exceeds the Threshold again.

Attack

Range: 0.3 to 100 ms

Sets the time it takes for the Expander to reach the attenuation specified by the Ratio parameter when the signal drops below the Threshold point.

Meter Zoom

Press Zoom to decrease meter range and have a more accurate metering.

Bypass Exp.

Press to bypass the Expander section of the MD

5.1 algorithm.

“LFE” parameters

These parameters are equivalent to the “LFE” Threshold, Range, Ratio, Attack and Release parameters.

Multiband5.1 algorithm – Expander – L M H page

Multiband5.1 algorithm – Expander – All LFE page

Pressing any parameter will assign this to Fader

This page holds all Expander Threshold, Range, Ratio, Attack and Release parameters for the Lo, Mid and Hi bands.

Multiband5.1 algorithm – Compressor – main page

“All” parameters

These parameters are equivalent to the “All” Threshold, Range, Ratio, Attack and Release parameters.

20 DB4 / DB8 MKII Algor ithms

Multiband5.1 algorithm – Compressor – main page

Pressing Threshold, Range, Ratio, Attack and Release keys will immediately assign Lo, Mid, Hi, All and LFE values for these parameters to Faders 1 to 4. Be aware that the range of the All parameter is relative to the settings of the same parameters in the Expander section.

Mul t i b and 5 .1

Threshold

Range: -25dB to 20dB (in 0.5dB steps)

Sets the Threshold level at which the Compressor starts to operate. The Threshold parameter relates to the Reference Level setting.

Example: If the Reference Level is set to -18dBFS, a Threshold setting of -4dB, will cause the compressor to start operating at -22dBFS.

Gain

Range: Off, -18dB to 12dB in 0.5dB steps.

Adjusts the gain after the Compressor.

If the Auto Make-up gain parameter is set to On in the Main page, these gains will already have been adjusted according to the Threshold and Ratio parameters.

Ratio

Range: Off to Infinity

Sets the Compression Ratio that must be performed above the Threshold point.

Attack parameters

Range: 0.3 to 100 ms

Sets the time the Compressor takes to reach the attenuation specified by the Ratio parameter when the level exceeds the Threshold point.

Multiband5.1 algorithm – Compressor – All LFE page

Pressing any parameter will assign this to Fader

“All” parameters

These parameters are equivalent to the “All” – Threshold, Range, Ratio, Attack and Release parameters.

“LFE” parameters

These parameters are equivalent to the “LFE” – Threshold, Range, Ratio, Attack and Release parameters.

Release parameters

Range: 20 ms to 7 sec.

Sets the time the Compressor takes to release the attenuation of the signal when the signal level drops below the Threshold point.

Meter Zoom

Press Meter Zoom to decrease meter range and have a more accurate metering.

Multiband5.1 algorithm – Compressor – All L M H page

Pressing any parameter will assign this to Fader

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Mul t i b and 5 .1

This page holds all Compressor Threshold, Range, Ratio, Attack and Release parameters for the Lo, Mid and Hi bands.

Limiter

The Limiter page is divided into three Sub-pages. One covering the Softclip section, one for the Full Range Limiter and one for the LFE Limiter.

Generic parameters in this algorithm:

Meter Zoom

Press Meter Zoom to decrease meter range and have a more accurate metering.

Bypass Limiter

Press to Bypass the Limiter section of the 5.1 algorithm.

Multiband 5.1 algorithm – soft clip page

Multiband5.1 algorithm – full Limiter page

Threshold

Range:

-12dB to Off

-6 to 0dB in 0.1dB increments

-12 to -6 in 0.5dB increments

Brickwall limiter for the five multiband channels. Threshold is always relative to 0 dBFS. LED on each Output meter indicates when Limiter is active.

Multiband5.1 algorithm – soft clip page

Softclip

Full Range Softclip

Range: -6dB to Off

Softclipper Threshold setting after the Compressor for the five multiband channels. Threshold is always relative to 0dBFS (Not the Reference Level.

LFE Softclip

Range: -6dB to Off

Softclipper Threshold setting for the LFE channe l only.

Release

Range: 0.01 to 1.00 seconds

Release time for the Limiter.

Ceiling

Range: -0.10dB to 0dB

Fine-tuning parameter setting the Ceiling for the Limite r.

22 DB4 / DB8 MKII Algorithm s

Mul t i b and 5 .1

Multiband5.1 algorithm – LFE Limiter page

LFE Limiter

Threshold

Range:

-12 to +3dB

-6 to + 3 in 0.1dB increments

-12 to -6 in 0.5dB increments

Brickwall limiter for the LFE channel. Threshold is always relative to 0dBFS. LED on each Output meter indicates when limiter is active.

Multiband5.1 algorithm – output page

Trim Levels

Output trims

Range: 0dB to -12dB in 0.1dB steps

Level trim of the Output channels. Only the fader is placed after these trims. These parameters can be used to trim the levels of the monitoring system, but please note that it also affects the recorded material.

Release

Range: 0.01 to 1.00 seconds

Release time for the Limiter.

Ceiling

Range: 0 to -0.10dB in 0.01dB steps.

Fine-tuning parameter setting the Ceiling for the Limite r.

Mute

Allows muting of each Output-channel.

Output Fader

Range: Off to 0dB Off to -40dB: in 3dB steps,

-40 to 0dB in 0.5dB steps

Output fader for all 6 Outputs. Can be controlled with the optional TC Master Fader connected to the GPI Input.

Compare

Easy switchable On/Off compare function for the entire MD 5.1 algorithm. This is not a bypass function as you are able to set a Compare Level (see below).

Compare Level

Range: -20 to 0dB

This function allows you to set a Compare level of the processed signal to match the unprocessed signal for better A/B listening.

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Mul t i b and 5 .1

24 D B4 / DB8 MK II Algo rithms

Mul t i b and 5 .1

EQ + Delay

English Manual 25

+ 66 hidden pages

TC Electronic DB4 MKII User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

About this manual

Introduction

Dynamics processing

EQ + Delay