This range of rack-mounting audio monitors have loudspeakers and LED level and phase meters fed by source selectors which accept both digital AES/EBU and analogue line level signals. All processing, including parametric equalisation and a comprehensive set of controls, is conducted in the digital domain, feeding an advanced stereo loudspeaker array in only one unit of rack space. The various models offer four stereo inputs, 20 stereo inputs, and four-channel dual mono types which have four meters. An optional expansion card extends this to include an SDI interface, de-embedding a further four stereo pairs; factory fitted options provide the facility to monitor Dolby E or Dolby Digital audio channels in HD-SDI, SD-SDI and AES/EBU signals.
Common Features
All models are built in welded, sealed, stainless-steel cases, with milled, anodised aluminium front panels. Measures to avoid compromise to the acoustic output include foam seals for the lid, foam sealant on XLR and USB connectors and silicon sealant applied to components to avoid movement or vibration.
The loudspeaker system is three way. The two drivers for left and right mid and high frequencies are mounted in moulded enclosures. The forward-facing bass unit is fed with a mono signal from the DSP based active crossover. A five-band parametric equaliser can be accessed for equalisation purposes using Windows-based remote control software.
The front panel is dominated by speaker grilles at either side. These have separate apertures for the MF/HF drivers and the internal LF unit. The source to be monitored is chosen with a dual-function rotary encoder. Inputs are categorised into ‘banks’, each of which can have a number of sources, which are chosen by pressing the knob, which steps through the banks which are available. The source is then chosen by rotating the knob. LEDS around the knob indicate which bank and source is selected. LED bargraph displays of level can be configured, excepting the RM-4C8, to follow this input selection, or the output of the system, after the ‘audio modifiers’, which provide dim, cut left, cut right, mono sum and phase invert functions and M+S encoding or decoding, using illuminated keys, some of which may be controlled by external signals. A phase bargraph follows the output of these ‘modifiers’, as do the rotary balance and volume controls, which feed a speaker protection limiter, headphone output, the crossover, power amplifiers and the speakers. Inserting a jack into the 6.35mm headphone socket causes the speakers to mute. LEDs indicate if the loudspeaker limiter is activated, if the selected source is within 0.5 dB or over of the point at which clipping occurs, and if a valid digital audio signal is present on the selected source. The brightness of all the indicators may be adjusted using a recessed screwdriver operated control. All the settings on the front panel are stored in non-volatile memory which is recalled at power-up. The audio level meters may be set to a variety of characteristics, by means of switches accessed from the underside of the case. Self-adhesive scale labels are provided for Nordic, BBC, EBU, DIN and AES digital PPM characteristics, dual PPM with VU scale, as well as standard and extended VU.
The rear panels have a type B USB socket, and 9-pin D-sub female connector for external control, a 25-pin male D-sub type providing remote inputs and outputs and a fused IEC power inlet, as well as the audio inputs and outputs. All models have a pair of XLR outlets which may be used to provide either an analogue line level or AES digital output of the source monitored, either pre or post the volume control. A blank plate covers the aperture for the optional expansion cards. The remote connector offers audio under-level, audio over-level and sustained phase-error alarms, which latch, and an non-latching AES/EBU lock output, all presented as open collector outputs. Mute, dim and alarm reset functions are implemented by connecting the appropriate pin to ground.
Sonifex SCi software, available free of charge as a download from Sonifex, when installed on a suitable PC, provides graphical access to all remote control and configuration options via both RS232 and USB interfaces. Alternatively, commands may be issued from any text-based terminal program.
Inputs: +18dBu, at 0dB gain, 20kohms, analogue, maximum; 0dBFS, 110 ohms, 32-192kHz sampling rate, digital, maximum. Common mode rejection: 60dB typical. Input gain: 0 to +18dB, 6dB steps. Response: 20Hz-20kHz +0/-0.5dB. Distortion: Better than 0.02%, 1kHz, +8dBu output. Noise: -84dB RMS, 0dB gain, below +8dBu output. Crosstalk: Better than -90dB / -85dB, 1kHz/10kHz, at 0dBu. Outputs: +18dBu, 50 ohms, analogue; 0dBFS, 110 ohms, 48kHz sample rate, digital. Speaker equalisation: Parametric, 5 bands, 0.25 to 2 octave bandwidth, 200Hz to 18kHz centre frequency, +/- 12dB. Crossover: 500Hz. Power amplifiers: 2x 5W, 1x 20W. Distortion: Better than 0.05%, at 1kHz, 3W, HF; 100Hz, 6W, LF. Noise: Better than -80dB referred to full output. Headphone output: 80mW, 32-600 ohms load. Acoustic output: 102dB SPL, peak, at 610mm. Power source: 85-264V AC, 47-63Hz, 60W peak. Dimensions: 480 x 305 x 44 (w x d x h)mm. Weight: 4.5kg.
Included accessories: Handbook, metering overlay labels, USB cable, IEC power lead.
Optional accessories: RM-HD1 HD-SDI Expansion Card, see below.
RM-2S4 - Four Analogue Or Digital Stereo Channels
This model has two horizontal multi-coloured, 53-segment bargraph meters which show the currently selected stereo source. The source selector offers a choice of four sources from each of four banks. As standard one of the four banks is available, which is fed by eight XLR connectors on the rear. These may be used for either analogue or AES digital inputs and are auto switching. The remaining three banks are for use when expansion cards are fitted.
RM-2S10 - Ten Analogue And Ten Digital Stereo Channels
This also has two horizontal multi-coloured, 53-segment bargraph meters, showing the currently selected source. The source selector offers a choice of up to ten sources, from each of four banks. The first bank is for the ten analogue inputs, the second for the ten AES digital inputs; the remaining two are for use with expansion cards. Three 25-pin D-sub connectors on the rear panel are used as the inputs. On the RM-2S10, the presence of active signal on a source input is indicated by green illumination of the corresponding source LED. The currently selected source is indicated by yellow illumination.
Where there is a mixture of up to ten analogue and digital inputs, selecting the auto-selection option may be useful. This will cause the RM-2S10 to switch automatically between the analogue or digital bank when a source is selected, depending on which is connected. Both the analogue and digital bank LEDS will be illuminated, and if a valid digital signal, for the selected source positions, is present, it will be selected. If not, the analogue source will be selected.
RM-4C8 - Dual Mono - Eight Analogue Or Four Digital Inputs
Useful for monitoring the audio channels in an SDI group, or groups of de-embedded AES/EBU channels, this model, unlike the others, is a dual mono design. It has four vertical, 26-segment, multi-coloured LED bargraph meters, displaying the four sources in the currently selected bank. The meters behave as input meters; they are not affected by the ‘modifier’ controls. There is an extra source selector on the right hand side of the front panel to select the source for the right hand speaker from the same bank as selected with the left hand control, which offers six banks. The rear panel has eight XLR connectors, designated as bank A and bank B. Within each bank, either two AES digital or four single channel analogue signals may be connected. The signals from the AES connections on XLR 1 will appear as sources 1 and 2, and the signals from XLR 3 will be sources 3 and 4. The analogue signals may be mono, or half of a stereo or M+S pair. They are auto-detected. The remainder of the banks are for use with expansion cards. Stereo or M+S pairs may be monitored by selecting the appropriate source on the two source selectors.
RM-HD1 HD-SDI Expansion Card
When fitted in the rear expansion port, RM-HD1 makes it possible for multiple AES groups embedded within a 3G, HD-SDI or SD-SDI video signal to be de-embedded and monitored. The expansion board can extract any of the four available AES/EBU groups (2 stereo pairs) from the video signal and connect them to the source selector for monitoring. The BNC input is auto-sensing for either SD, HD, or single link 3G input formats. The SDI input is equalised, internally re-clocked and re-transmitted via a BNC output connector to pass to external equipment such as another monitor unit. This card may be fitted by the user.
Compatible with RM-2S4, RM-2S10, RM-4C8
Supported standards: SMPTE 259M-C (SD), 270 Mbps; SMPTE 292M (HD), 1.485/1.4835Gbps; SMPTE-424M (3G), 2.97/2.967Gbps. Input impedance: 75 ohms. Output level: 800mV, +/-10%. Output impedance 75 ohms. Return loss: better than 15 dB, 1.5GHz. Embedded audio: SMPTE-272M-ABC/SMPTE-299M, 48kHz synchronous (Audio must be synchronous in SD), HD asynchronous.
RM-HDE1 HD-SDI Expansion Card - Dolby E
For use with the RM-4C8 only, the RM-HDE1 expansion card provides the facility to monitor embedded audio channels within a 3G/SD/HD-SDI video signal, either non-encoded linear PCM, Dolby E or Dolby Digital. It is available as a factory fitted upgrade, or ready fitted to the RM-4C8, as the RM-4C8-HDE1.
All channels in the selected group can be monitored visually and any two channels can be selected to be monitored on the speakers. If a Dolby E or Dolby Digital input is detected on the selected channel, a button flashes to indicate that decoding is possible. Pressing the 'CHANS' button displays the Dolby Digital 5.1 or Dolby E 8 channel signal, using the four bar-graph meters. Each meter is split into two sections allowing the user to view L, R, C, LFE, Ls, Rs for Dolby Digital and an additional Lt, Rt for Dolby E. Full Dolby metadata is available using the SCi remote control software.
Supported standards: SMPTE 259M-C (SD), 270 Mbps; SMPTE 292M (HD), 1.485/1.4835Gbps; SMPTE-424M (3G), 2.97/2.967Gbps. Input impedance: 75 ohms. Output level: 800mV, +/-10%. Output impedance 75 ohms. Return loss: better than 15 dB, 1.5GHz. Embedded audio: SMPTE-272M-ABC/SMPTE-299M, 48kHz synchronous (Audio must be synchronous in SD), HD asynchronous.
RM-E1X AES/EBU Expansion Card - Dolby E - XLR
For use with the RM-4C8 only, this card provides the ability to monitor a digital audio stream containing either linear PCM or Dolby encoded audio. The RM-E1X has an male XLR input to accept a AES/EBU input, a re-clocked loop-through output is provided by a female XLR. It is available as a factory fitted upgrade, or ready fitted to the RM-4C8, as the RM-4C8-E1X.
Dolby data is decoded and passed to the Reference Monitor as either a stereo down-mix or the full complement of individual channels. If the signal is standard linear PCM, then this audio data is simply passed straight through. The input is re-transmitted with minimal delay.
Input and output: AES/EBU, 110 ohms, balanced, transformer-coupled. Sample rates: 32-48kHz. Audio formats: Linear PCM; Dolby E, 16, 20 and 24-bit; Dolby Digital, 16 and 32-bit.
RM-E1B AES/EBU Expansion Card - Dolby E - BNC
Similar to the RM-E1X, this card, which is for use with the RM-4C8 only, offers the same facilities as the RM-1EX, excepting that the inputs and outputs use BNC connectors. It is available as a factory fitted upgrade, or ready fitted to the RM-4C8, as the RM-4C8-E1B.
Input and output: AES/EBU, 75 ohms, unbalanced, transformer-coupled. Sample rates: 32-48kHz. Audio formats: Linear PCM; Dolby E, 16, 20 and 24-bit; Dolby Digital, 16 and 32-bit.