Manual

Low Latency
Thethroughputlatencyofasinglemasterboardisonly
1.33ms,regardlessofhowmuchprocessingisbeing
used.EachadditionalPCBaddsonly0.125ms.
200inputscanbehandledwithonly4.33mslatency
(1.33msforthemasterPCBplus24additionalPCBsat
0.125mseach.
Otherexamplesinclude:
• 264inputswithonly5.33mstotallatency
• 328inputswithonly6.33mstotallatency
• 456inputswithonly8.33mstotallatency
• Unlimitedmaximumwith1msaddedforeachad-
ditional64inputs(8boards)
Latencyisnotaffectedbytheamountofprocessingbe-
ing used at any stage in the signal chain.
Everyinputisautomaticallysynchronizedtoeliminate
phasedifferencesbetweentheinputsincludedinthe
nalmixes.
*US Patents 5,414,776 and 5,402,500
Seamless Automatic Mixing
Lectrosonicspioneeredadaptiveproportionalgainauto-
maticmixingalgorithms.Theproprietaryalgorithm*em-
ployedinASPENisaseamlessprocessthateliminates
abruptswitching(gating),controlsacousticfeedbackand
suppressesbackgroundnoise.
Allactiveinputchannelsaresummed,andthenthelevel
ofeachchanneliscomparedtothetotalsum.Channels
are then attenuated so that the resulting sum is equal to
onechannelatfulllevel(NOM=1)withtheloudestchan-
nelstilltheloudestinthemix.Thealgorithmoperatesin
thesamemannerthatahumanoperatorwouldinmixing
a conference manually on a console. Unused mics are
attenuatedandthoseinuseareemphasized.
Thisautomixingalgorithm,workinginconjunctionwith
theAECintheASPEN Conferenceprocessor,provides
impressiveechocancellationandnoisereduction.
The algorithm includes a unique automatic skewing
processthatappliesasubtleprioritytothechannelthat
hasbeentheloudestforthelongestperiodoftime.The
skewingfurtherreducesinactivechannelsandprevents
comb filtering by never allowing two channels to be
mixedatthesamelevel.
Theautomixingtakesplaceatthematrixcrosspoints,
whichallowseachinputsignaltoexhibitadifferentbe-
haviorateveryoutputinthesystem.Forexample,input
channel4couldbeconguredforAutobehavior(normal
automixing)atoutput6forlocalsoundreinforcement,
Directbehavior(noattenuation)atoutput10forrecord-
ing, and so on. There are five different behaviors avail-
able:
• Direct-noattenuation
• Auto-normalgainproportionalautomixing
• Phantom-specialmodeformix-minussystems
• Override-dominantinautomixingactivity
• Background-subordinateinautomixingactivity
The Phantommodeallowsthechanneltoparticipate
intheautomixingalgorithmatanycrosspoint,butnot
delivertheactualaudiosignaltotheoutput.Thisisused
tocombinezonesforroom-wideautomixingactivityina
mix-minusreinforcementsystem.Theautomixingaction
iscommontoallzones,buttheaudiosignalroutingto
theloudspeakersremainsasisitconguredinthesetup.