Meridian Audio G61 manual Ambisonics and Super DSP preset parameters

Page 41

3 6

D S P p r e s e t s

Ambisonics

The Ambisonics DSP preset can decode UHJ format, the two- channel stereo-compatible encoding found on Ambisonically- recorded discs and broadcasts. This material is specifically encoded for surround reproduction and can give breathtakingly realistic sound when replayed using the digital surround controller.

Ambisonics surround sound is quite unlike conventional stereo. A special microphone technique picks up the sound of the original performance in all three dimensions, allowing an archive to be made which describes the soundfield exactly at that position. The microphone signals are then encoded using a phase-amplitude matrix to allow the effect to be conveyed on two-channel carriers (like FM radio, LP, or CD).

The digital surround controller uses accurately matched, frequency- dependent, phase-amplitude matrices to decode the signal and construct the signals for each speaker feed.

Ambisonics and Super DSP preset parameters

The fundamental difference between Ambisonics surround sound and conventional stereo is that the signals from all the speakers combine to produce a coherent soundfield at the listening position, giving the illusion that you are sitting inside the recording space whether you are at the exact central seat or well off to one side.

Of all the signal-processing options, Ambisonics is the one that requires the greatest attention to speaker choice and positioning.

Super

Super synthesises a signal from a conventional stereo recording or broadcast so that it can be decoded using the Ambisonic decoder. The result is especially effective for two particular types of recordings:

Those using true coincident microphone techniques.

Multi-tracked or multi-miked recordings.

Parameter

Options

What it changes

Width*

0 to 1

The width of the image.

Row†

A, C, E, G, I, K, M

The seating position; the letters are like rows in a hall.

Channels

7, 6, 5, 4

The number of speakers.

R Filter

Off, 3kHz, 7kHz, 9kHz

The cutoff of high frequencies from the rear surrounds.

S Filter

Off, 3kHz, 7kHz, 9kHz

The cutoff of high frequencies from the side surrounds.

*Super only.

 

 

†Ambisonics only.

 

 

Image 41
Contents R I D I a N G S E R I E S G61 Digital Surround Controller Installation Guide Refer all servicing to approved service personnel Safety warningsTo avoid overheating To avoid interferenceContents Sales and service in the USA Sales and service in the UKCopyright and acknowledgements Tel +1 404 344 Fax +1 404 346 Part no G61/1Introduction Smart Source featureInputs Formats supportedT r o d u c t i o n Specifications T r o d u c t i o n Unpacking Installing the digital surround controllerTo connect to this Use this connectorAudio inputs To connect to an analogue source eg TV tuner To connect to a digital source eg G07 24-bit CD Player#$ $6$ ! Player Use this output Audio outputsTo connect the G61 to Meridian DSP loudspeakers $30 n -!.!2Phono Lead M33To connect an active subwoofer eg Meridian M1500 or M2500 3UBWOOFER $IGITALI3URROUND #ONTROLLERScreen Use this connector To connect to thisCommunications connections Auto Configuration Wizard Configuring the digital surround controllerTo run the Configuration Wizard To do thisReset all settings? Reset settingsTo reset the configuration TypeType Speakers Music Sub Logic Sub TypesSelect speakers To configure the speakersOne To change an optionOption Values Description Speaker optionsTo configure a source Configure sourcesPress Source When you have finished configuring sources Radio UseOption Values Source optionsOther settings Stage 4 Configuring other settingsTo configure other settings To change a settingSettings Page Introduction Using a Sound Pressure Level meterCalibrating the system To exit from the calibration procedure To start the calibration procedureTo complete the calibration procedure Left Level +0.0dBDistance Calibration testsLevels Left Phase Fine tuningSetting What it sounds like Left DistanceLeft Size Speaker sizeSizes set to zero Sinewave sweep test Using the Sine/Sub/Sens controlsSubwoofer crossover frequency CD Xover 85Hz88.5Hz CD Sine 80.0Hz81.5Hz Pause 80.0HzTo adjust the sensitivity of a source Setting up sources4V Peak TV 2.0V ClipDSP presets DSP presetsSpeaker layouts Layout DescriptionStandard-rate audio, downsampled if necessary Parameter Range Default What it changesStandard parameters Music Music and Trifield DSP preset parametersTrifield Parameter Options What it changesSuper Ambisonics and Super DSP preset parametersAmbisonics PLIIx Music MusicLogicStereo and Direct PLIIx Movie and PLIIx THX DSP preset parametersPLIIx Movie and PLIIx THX Surrounds Rear, Side, AllTV Logic Mono DSP preset parametersMono Parameter OptionsDiscrete Discrete and Cinema DSP preset parametersCinema 28dB to 0dB THXUsing dynamic range control For example Defining your own presetsTo save the preset settings For example, you could change the name to To clear a user-defined presetStored General operating problems TroubleshootingStandby light not lit Erratic or unexpected system behaviourRemote not working Audio problemsUnit is overheating Hum on analogue inputThere is a hiss when starting DTS LaserDiscs or CDs Audible hiss at high volume settingsSound not clear Centre not workingPreset changes unexpectedly with a multichannel Source Cleaning MaintenanceTo clean the case, display panel, and keypad To clean the audio and video connectionsGuarantee Service and guaranteeService Calibration procedure 25 moving between tests 26 starting Academy DSP parameter 39 accessoriesGuarantee +2+2 DSP parameters DSP presetsPLIIx Music Panorama Rear THXSubwoofer crossover frequency 30 Super DSP preset Types 16 THX DSP preset 40 UHJ format THX Music DSP preset+2+2 DSP parameters