TC Electronic SYSTEM 6000 MKII Algorithm Manual

51
MDX 5.1
Introduction
MDX5.1isahighresolutiondynamicsprocessorfor
multichannel signals. It presents a sophisticated new angle
to dynamic range control, and is an alternative to traditional
compression and limiting techniques.
MDX5.1iscapableofbringinguplowleveldetail,rather
than boosting everything, and then having to limit the
transientsafterwards,seeFig1.Lowlevelliftcanevenbe
applied to specific channels selectively in one, two or three
frequency bands.
Years of investigation into early listener fatigue in digital
audio has led TC engineers to the conclusion that limiters
and clippers are non-ideal matches for digital mastering
and delivery. The blind limiting approach adds pronounced
transientandaliasdistortion,plustheriskofgenerating
even more distortion in reproduction equipment and data
reductionsystems.Unfortunately,thisunfriendlytypeof
distortion cannot be undone, and with the type of level
detection employed today, it is not even visually detected.
The music industry, for the past ten years, has witnessed
an ignorant quest for loudness rather than audio fidelity.
Today, we stand on the verge of also damaging music and
filmheritageinmultichannelformats.MDX5.1hopefully
helpsmakesuchascenariolesslikely.Still,pleasebe
cautious with bringing levels to the max. More processing
may always be added downstream.
Low level detail enhancement for mono and stereo
signals can be obtained using the MD4 algorithm in
DXP mode.
Fig 1. DXP processing vs. traditional Compression and
Limiting.
Note how already loud signals are unnecessarily affected
when relying on limiting and clipping.
Applications
MDX5.1offersextensiveinter-channellinkingpossibilities,
and is well suited for both music and film material.
The ingenious topology of System 6000 allows for low
latencyprocessing(below0.5ms,equivalenttomoving
a microphone approximately 16 cm or 6 inches), which
makesMDX5.1advantageousevenforliveortheatrical
applications.
OntheMainpage,MDX5.1featuresInputGaincontrols
fortheMainChannelsandfortheLFEChannel.This
enables gain and 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.
UsetheInputGainsasoverloadprotectedlevel
trims in a critical realtime system, such as
broadcast, OB, live music or theatre.
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 channels to Sidechains. 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.
OntheDXPpages,MDX5.1hasseparatecontrolsfor
Sidechain1-3plusLFE.Thisenables,forinstance,
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.
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.
MDX5.1features48bitfixedpointprocessingthroughout.
Split and reconstruction filters are phase linear when the
algorithm is used in multiband modes.

TC Electronic SYSTEM 6000 MKII Specifications

General

Brand	TC Electronic
Model	SYSTEM 6000 MKII
Category	Computer Hardware
Language	English