HDMI Audio Processor by xwm19580


                                                                                                        HDMI Audio Processor

                                                                                                                  Product Information

                                                                                                    Product highlights
                                                                                                    Six-input HDMI switch.
                                                                                                    HDMI video output.
                                                                                                    Extracts up to eight channels of
                                                                                                    high-resolution audio from the
                                                                                                    HDMI data stream, supplying them
                                                                                                    to separate audio-only outputs.
                                                                                                    Connects HDMI audio direct to a
                                                                                                    Meridian processor.
                                                                                                    Smartlink coaxial digital audio
                                                                                                    output (up to 8 channels).
The Meridian HD621 HDMI Audio                     the HD621 to the display, while enhanced          Multichannel Meridian High
Processor extracts the audio signal               digital audio is fed to the sound system. The     Resolution (MMHR): balanced
from the data stream at the HDMI                  HD621’s audio outputs connect directly            digital audio output via RJ45/Cat
input and provides separate audio                 to an existing Meridian processor, offering       5 cable (up to 8 channels).
outputs suitable for a Meridian                   complete and immediate system integration.        Up- and down-sampling of digital
surround controller. Internal buffering                                                             audio.
and processing improves audio                     The HD621 includes Meridian’s
                                                                                                    Audio FIFO buffering and
quality. It is also a 6-into-1 HDMI video         comprehensive FIFO buffering system and
                                                                                                    resolution enhancement improves
switch, allowing all your HDMI-based              resolution enhancement, based on that used
                                                                                                    PCM audio received via HDMI.
components to be fed via a single                 in the 800 Series. This cleans up incoming
video cable to your display.                      PCM digital audio signals, removing the           Lip-sync control compensates for
                                                  timing and other degradations audio suffers       latency resulting from external
HDMI (High Definition Multimedia Interface)       when combined with video in HDMI. The             digital video processing.
connectors are a common sight on HD video         audio is clocked into a dual-section buffer       Keeps HDMI video signals away
and other equipment. Usually employed to          and clocked out again after re-shaping            from your audio equipment,
carry digital video, HDMI also carries digital    the digital audio waveform structure and          minimising signal degradation.
audio. However, having both audio and video       re-timing with extremely accurate reference
on the same cable is not always convenient,       clocking signals. The result is a significant
nor does it deliver the maximum level of          and audible improvement in quality, including     Outline specification
quality of which digital multimedia signals are   accuracy of stereo and surround imaging and
capable.                                          localisation, as well as overall sonic benefits   Form factor
                                                  including improved transparency at the high       •	1U	19in	rack	mounting
Digital video signals have traditionally been     frequency end. The unit also allows for up-
the bane of those in search of the best audio     and down-sampling of digital audio signals,       Power
                                                                                                    •	Internal	universal	power	supply,		
quality. They include very high frequency         to provide outputs at standard (44.1/48 kHz)        100–250Vac
signals with very fast rise-times and thus        or high (88.2/96 kHz) resolution sampling
tend to radiate an enormous spectrum of           rates.                                            Connections
harmonics. This unwanted radiation can leak                                                         •	Power	input	(IEC	connector)
into audio circuits, causing noise and even       A configurable audio delay system is built in,    •	DB9M	Sub	RS232	serial	connector
                                                                                                    •	BNC	and	DIN	Meridian	Comms
disrupting the signals themselves, causing        allowing you to ensure that sound is always
                                                                                                    •	Six	HDMI	input	sockets
muting, interpolation and other effects. In       in perfect synchronisation with the picture,      •	HDMI	output
particular, digital video (indeed video of any    even if the image is being processed with         •	8-channel	MMHR	digital	audio	out	
sort) can leak into analogue audio circuitry,     significant amounts of latency. The HD621           (RJ45)
causing hum, buzz, noise and other unwanted       also ensures that the HDMI interface is           •	8-channel	coax	digital	audio	out	(4	x	
artifacts.                                        driven correctly, which may result in improved      phono)
                                                  video as well as audio performance.
The HD621 solves these problems at a                                                                Front-panel Indicators
stroke, while allowing all your components        The HD621 is housed in an elegant black           •	Power	LED
that deliver video via HDMI a common              slimline 1U rack-mount panel for unobtrusive      •	6	x	HDMI	Input	LEDs	(selected	input	
destination. A single cable can be run from       installation.
                                                                                                               HDMI Audio Processor

Front panel                                     SmartLink Output – These four phono               HDMI audio processor reclocks PCM digital
                                                sockets each carry a pair of digital audio        audio information received via HDMI and
The front panel (see above) simply shows a
                                                channel signals at up to 96 kHz sample rate:      re-times it, clocking it into and then out of a
power LED plus six LEDs indicating which
                                                1/2, 3/4. 5/6 and 7/8. These are encrypted        FIFO (First In, First Out) buffer system. This
input is currently selected. A manual select
                                                to Meridian High Resolution (MHR)                 ensures that the audio extracted from the
button allows you to step through the inputs.
                                                specifications when carrying high resolution      HDMI stream is of the highest quality.
Rear Panel
                                                                                                  HDMI carrying both video and audio is not
The rear panel features the following           Power input socket, power switch and fuse         the best environment for digital audio and
connections (L to R):                           holder – the power supply accepts a standard      the integrity of the audio signal can be
                                                IEC power connector and is a universal            compromised, especially as far as timing
RS232 DB-9M Sub connector - this enables        voltage type accepting voltages between 100       is concerned, where the rise-time of digital
the processor to be controlled remotely via     and 250Vac at 50/60 Hz.                           audio signal pulses can be lengthened,
serial command.                                                                                   resulting in uncertainties about exactly when
                                                Up/downsampling of digital audio                  the value changes between 0 and 1. This
Meridian Comms BNC and DIN                                                                        results in timing irregularities which can
                                                The MMHR and SmartLink outputs can be
connectors – these enable the processor                                                           adversely affect stereo and surround imaging
                                                set to deliver either standard (44.1/48 kHz)
to be integrated with a Meridian audio/                                                           and blur the soundstage. These problems are
                                                or high resolution (88.2/96 kHz) sample rate
video system and controlled by it, for                                                            minimised by the buffering stage resulting in
                                                digital audio, with resolution enhancement to
example, switching the HDMI input when the                                                        the highest possible audio quality from the
appropriate selection is made via the system                                                      original HDMI signal.
                                                When set to standard rates, the output
                                                                                                  Non-Meridian sources sending audio via
                                                is either 44.1 or 48 kHz irrespective of
HDMI Inputs H1–6 – These follow the                                                               HDMI should in most cases be configured
                                                the input rate, high sample rates being
standard input identification in a Meridian                                                       to decode the audio to PCM in the source
                                                downsampled by a factor of two (ie an 88.2
system (this can be overridden when the                                                           component to take advantage of the
                                                signal is downsampled to 44.1, while a 96
system is being configured).                                                                      resolution enhancement and upsampling
                                                kHz signal is downsampled to 48 kHz). 44.1
                                                                                                  features of the HD621. As a general rule,
                                                and 48 kHz rates are unchanged.
HDMI Output: Video – This outputs the                                                             audio from Meridian sources is fed direct to a
video information present on the selected                                                         Meridian surround decoder via SmartLink.
                                                When set to high rates, the output is
HDMI input. By default, it does not carry the
                                                always either 88.2 or 96 kHz, irrespective
audio information, but can be configured to                                                       Lip-sync Delay
                                                of the input rate. Standard sample rates
do so.
                                                are upsampled by a factor of two using            The processor also includes a configurable
                                                Meridian’s powerful DSP technology, so that       audio delay of up to 85ms to allow lip-
MMHR Output – This RJ45 connector
                                                input signals of 44.1 and 48 kHz are output       syncing in the event of a delay between the
carries eight channels of balanced digital
                                                at 88.2 and 96 kHz respectively. 88.2 and         audio and video. This is often the case when
audio data at up to 96 kHz sample rate
                                                96 kHz input signals are passed with their        an amount of digital video processing is
conforming to the Meridian Multichannel
                                                sample rates unchanged.                           being carried out, which can add considerable
High Resolution (MMHR) specification, with
                                                                                                  latency to the system (video processing is
encryption where required to carry high-
                                                FIFO Buffering                                    more complex, thus more time-consuming,
resolution audio data.
                                                                                                  than audio processing in most cases).
                                                In addition to the features noted above, the

Meridian Audio Limited,	Latham	Road,	Huntingdon,	Cambridgeshire	PE29	6YE,	UK.	T	+44(0)1480	445678	F	+44(0)1480	445686	E	info@meridian-audio.com
              Meridian America Inc., 8055	Troon	Circle,	Suite	C,	Austell,	GA	30168-7849,	USA.	T	+1(404)	344	7111	F	+1(404)	346	7111

                                                                                                HD621DS-ENG	v1.4	•	REƒ	•	P88379	•	20090114

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