Speaker System Enhancement for Sonifex Reference Monitor Range


Sonifex released the Reference Monitor range of three 1U rack mount audio monitors in 2008 and these products have been installed in many OB vans and TV/radio rack-rooms around the world. In October this year, after extensive research, the products were released with a new speaker system.

Managing Director Marcus Brooke commented: “We’ve had a lot of compliments about the sound of our Reference Monitor products and we’re constantly looking at ways to improve our designs and re-appraise our products. Getting an even balanced sound from a 1U rack based product isn’t easy and we’ve looked at different methods of improving the sound since the products’ launch: different porting methods, different chassis materials, different damping methods, different cross-over points, different EQing and also different speakers. The new speakers are larger in size, allowing more movement and we’ve been able to get a flatter more natural response with them. The new speaker system offers a new clarity for monitoring in a 1U rack”.

As well as altering the speaker system, limiting has been introduced per speaker instead of across the mix of the 3 speakers, and this, together with a slightly higher power output allows the new speaker system to be almost twice as loud as the previous version.


The Reference Monitor range of monitors are unique in that they also contain a 5 band parametric EQ, which is configurable via a USB connection, so the sound of the monitor can be tailored individually for the environment. For example an OB van or equipment room may have a poor bass response, so this could be boosted at particular frequencies where there is a dropout. The three-way loudspeaker system is fed via a DSP-based active crossover and a trio of highly efficient Class-D amplifiers.

All Reference Monitors are now shipping with the improved speaker system.

General information on the Reference Monitors
The monitors are 1U rack-mount units offering quality loudspeaker monitoring and accurate, high-resolution metering of up to twenty stereo audio sources (and de-embedded/Dolby decoded audio from an HD-SDI stream with the addition of an optional expansion card). Sources may be in any mixture of analogue and AES/EBU digital formats, with sample rates up to 192kHz accepted. The addition of a 5 band parametric EQ to the units is a unique feature that allows you to alter the monitors response either to account for poor acoustics in the room that the monitor is mounted in, or to suit your particular listening tastes.


Sources are selected via a front panel rotary encoder, with clear LED indication of the current selection. A pair of line-level audio outputs, configurable as analogue or AES/EBU digital, follow the selected source at either a fixed level or one mirroring the loudspeaker volume.

The level of the chosen source is displayed on a pair of bright, multicoloured 53-segment bargraph meters, with a choice of seven accurately modelled scales/responses to suit different applications and local preferences. A separate phase meter indicates channel correlation or phase error conditions. On the rear panel, open-collector alarm outputs provide hardware indication of sustained underlevel, overlevel and phase errors.Six illuminated pushbuttons provide access to a range of audio 'modifiers' - instant dimming of the volume, 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 the DIM and MUTE functions.

Each unit can be accessed remotely via both USB and RS232 connections.