Review: Resolution Jan/Feb '05
By Rob James

SPL Model 2381

You have the DAW but you need to be able to hear what you’re doing. Better still you’sd want to be able to interact with proceedings in a logical and convenient manner. Some buy a desk for just these functions but ROB JAMES suggests you investigate a monitor and talkback controller.

MONITORING CONTROL. Two words that strike fear into the hearts of installation engineers. Choosing a console is a doddle by comparison. This subject can create more quiet (and not so quiet) controversy than all the rest put together. Don’t think it has gone away in the digital age. If anything, monitoring is even more of an issue than before. German manutacturer, Sound Performance Lab, SPL, has an interesting and original take on this scene. Eschewing the manifold options a digitally controlled monitor system can offer, SPL has instead gone back to basics. The result is a simple, uncomplicated solution to the many monitoring problems thrown up bv digital workstations.

At UK£499 (inc.VAT) the SPL Model 2381 Monitor and Talkback Controller (hereafter MTC) combines volume level control, source switching and loudspeaker management for stereo monitoring, with talkback and cue mix functions. The MTC shares a number of characteristics with its 2489 Surround Monitor Controller sibling. For a start it is built like the proverbial tank and is similarly challenging on the aesthetic front. Being charitable, there is a vintage look and feel to both units. The internal design philosophy is, perhaps unsurprisingly, the same.

SPL’s renowned electronic balancing and a pretty purist approach with no VCAs, DACs or active switching. This results in performance figures well within the desirable range for professional use and a subjectively excellent sound. The ‘vintage’ feel extends to ease of use. This is true “one knob or button per function” stuff. The switches need a firm press and, like the detented pots, are very positive in action. There arc no monitor trim pots. As SPL correctly points out, the majority of active speakers and power amplifiers are already equipped with input trimmers so why compromise the signal path with duplication? In any case, if there arc multiple, adjustable attenuation and gain stages in the path, there are more chances to get the alignment wrong.

Everyone has their own idea of the ideal panel layout. Although I would lay the panel out somewhat differently, the control positions quickly become instinctive, a primary requirement of a monitor controller. Unlike a workstation GUI the MTC doesn’t move about or become hidden behind other windows.
The MTC enables overdubbing with true zero latency and, if a little thought is expended on operational set-ups, covers most, if not all, requirements when using a workstation with real people and real external equipment—not just a bunch of files. The four stereo 2-track inputs simplify monitoring of outside sources and the stereo Slave output allows for external metering and/or an additional record feed. 1 suspect the MTC may also have applications in the theatre world thanks to its mix of features and especially the multiple speaker outputs.
For workstation recording applications where a mixer would be overkill or where the existing mixer does not have anything beyond rudimentary monitoring, the MTC will prove ideal. For more complex applications I can see distinct possibilities in cascading an MTC with its sibling the 2489. The cost of both units together is still considerably less than the cheapest microprocessor controlled surround monitor controller and the sound will arguably be better.

The world of the workstation is complicated enough without trying to perform real-time monitoring operations via the same user interface. If you routinely make live recordings into a workstation, do your working practices and productivity a favour and consider the benefits a monitor controller can bring, then put the MTC on the shortlist.

Connection and operation
The steeply sloping front panel has a row of 12 light grey round latching push switches, each with an associated
indicator LED above it, the Power LED and the talkback microphone. The first six buttons select and sum sources to the MTC monitor bus, Musician, Mix, 2TrackA, 2TrackB, 2TrackC and 2TrackD. The next three buttons toggle the three pairs of Speaker outputs on and off, SP1, SP2 and SP3. Mono sums the left and right channels on all the three monitor outputs. Dim attenuates the level to all speaker and headphone outputs by around 20dB. HP On toggles the Headphone output on and off.

Below, the three left-hand pots make up the Cue Mix section with individual control over the Musician and Mix input and an overall Volume control. The centre section has a light grey non-latching push-to-speak talkback switch, which also activates the Dim function when pressed, an indicator LED and Level control pot. The final section contains the larger control room Volume pot, the Headphone socket and a Source Blend pot determining the balance between the Musician input and the summed Mix and 2Track inputs. The scale around the Volume knob is calibrated in percentage of maximum output. This can easily be calibrated and marked, using a pencil or tape, with your preferred SPLs.

Like the 2489 Surround Monitor Controller, the rear panel demonstrates an unusual level of understanding of the way many people have to work. All the legends are printed the ‘normal’ way up and upside down so they can be read when peering myopically over the top of the unit. The majority of connections are 1/4-inch jacks, electronically balanced or unbalanced if a two-pole plug is used. The exceptions being 2Track inputs C and D on phonos with an extra 10dB of gain to bring consumer level sources up to a similar level as the rest.
The three pairs of Speaker connections are XLR. An additional XLR Slave output is provided for external metering or recording. This takes the summed output of all active inputs except the Musicians input, which is only intended for latency-free monitoring rather than recording. Two further jacks provide separate talkback output and enable an external switch to be used.

Find out more about the SPL Monitor & Talkback Controller