The RM-2S4 is a 1U rack unit offering high-quality speaker monitoring and a precise, high-resolution measurement system capable of handling up to four stereo audio sources and more with the addition of optional expansion cards. Sources can be in any mix of analogue and AES/EBU digital formats, with accepted sample rates up to 192kHz. Audio inputs can be analogue or digital as they are auto-switching using the left Neutrik™ XLR for AES/EBU, or both Neutrik™ XLRs for analogue inputs and can be used in any combination.nnAnalogue inputs can be balanced or unbalanced in any combination. Digital inputs have switchable AES/EBU termination for bridging (short distance) operation and there is additional global input gain available for low-level analogue and digital sources.nnSources (and additional source banks, if installed) are selected via a front panel rotary encoder, with clear LED indication of the current selection.nnThe level of the chosen source is displayed on a pair of 53-segment, multi-coloured, bright bargraph meters, with a choice of seven accurately modelled scales/responses to suit different applications and local preferences. Clear scale labels are provided to allow you to choose the displayed scale and meter brightness can be adjusted from the front panel. A separate phase meter indicates channel correlation or phase error conditions. On the rear panel, open-collector alarm outputs provide hardware indication of prolonged under-level, over-level, phase error and digital source lock conditions.nnSix illuminated push buttons give access to a range of audio 'modifiers' – instant volume attenuation, individual muting of each audio channel, stereo to mono conversion, phase inversion and Middle+Side transcoding. On the rear panel, logic-level inputs allow direct remote access to DIM and MUTE functions.nnThe three-way speaker system is powered via a DSP-based active crossover and a trio of highly efficient Class-D amplifiers. Careful attention to speaker selection, materials and enclosure design, along with active DSP equalisation, ensures a flat response and exceptional reproduction for such a shallow unit. A protection limiter prevents speaker damage under overload conditions and the front panel headphone socket automatically mutes the internal speakers when a plug is inserted.nnA Balance control allows you to alter the stereo image of the left and right channels.nnAn additional five-band parametric equaliser is accessible for room equalisation via the Windows-based Sonifex SCi remote control software. Source selection, status monitoring and unit identification functions, as well as firmware updates to add additional functionality, are all remotely accessible via USB and RS232 connections in conjunction with the Sonifex SCi software. The open control protocol also allows operation with terminal programs or custom applications.nnOptional additions to the RM-2S4 include HD video input expansion cards, allowing de-embedding and monitoring of multiple embedded AES groups in an HD-SDI or SD-SDI signal, either with (RM-HDE1) or without (RM-HD1) Dolby® E or Dolby® Digital encoding. The RM-2S4 operates from global mains voltages (85-264V AC, 47-63Hz) without adjustment.