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Studio Technologies StudioComm 76DB 77B Digital Surround Monitor Loudspeaker Control System

This monitoring controller is an easily implemented, amply flexible, and transparent performer.

Avoiding unnecessary stages of D/A and A/D conversion has been a goal in digital production since the outset. With loudspeaker manufacturers now offering monitors with digital inputs and highlevel, final-stage conversion, one of the last pieces of the puzzle has fallen into place. But with many DAWs and digital consoles, bridging a level controlled digital signal between the production chain and the monitors has been cumbersome, if not impossible. Studio Technologies, long a provider of outboard monitor controllers, has introduced its StudioComm 76DB/77B surround monitoring system with a fully digital production chain in mind.


The 1U 76DB is the core of the system, housing the signal chain functionality of a console center section, including flexible source selection (six input choices can be configured from two 5.1 inputs and three stereo inputs), volume control (including user-specifiable reference level and dim functions and mute) and channel solo capability. Advanced capabilities included “channel pop” solo mode (where the selected channel(s) “pop” up in the mix by 6 dB while non-soloed channels are attenuated by -6 dB, and these offsets are user adjustable); downmix from 5.1 to stereo (which can also include the LFE channel, or not, your call) and stereo to mono; volume display in dB SPL (requires simple user calibration with a sound level meter); and dialnorm adjusted monitoring (where the selected output is adjusted per Dolby E Dialnorm coefficients in a “follow-me” mode — the rear RS-485 port is used to input a metadata stream).

The 76DB has no controls on the chassis; the front panel has status lights for Sync, Metadata presence and 77B control console presence. The 77B control console is connected and powered via a DB9 cable. Roughly 7 x 5.5 inches, the wedge-shaped controller is small enough to find a home on most work surfaces while having a non-crowded control surface for the 18 buttons and the rotary controller/volume knob. The buttons are clustered by function with LEDs to indicate status and a numeric display for showing volume/SPL or dialnorm (along with a few alternate displays like sample rate and setup info). Up to four 77B controllers can be connected to a single 76DB. Inputs can include two 5.1 sources and three stereo sources.

The packed 76DB rear panel is home to inputs and outputs for the unit. Input to the 76DB utilizes the AES3id specification — the unbalanced, 75-ohm BNC version of the 2-channel AES3 digital audio interface (these inputs will accept S/PDIF signals as well). Two full 5.1 sources (six channels across three connectors per input) can be accommodated, along with three stereo signals (10 BNCs are fitted, the final one for inputting word clock, AES11/DARS, AES3 or video sync [bi- or tri-level]). Samples rates of up to 192 kHz/24-bit are accommodated (one stereo input is fitted with sample rate conversion capability, to conform, say, a CD player out to the system sample rate).

Eight AES3 outputs are available on a single DB25 connector, requiring a fan-out cable — DB25 to eight XLR males using the Tascam DA-88 pin-out (the outputs can also be configured for AES3id operation). Three of the AES3 sends are used for pre-fader surround outputs (configurable as either AES3 or AES3id outputs to feed outboard meters or other monitoring gear). Two of the AES3 sends are stereo signals, one a direct output of stereo input “C” with selectable sample rate conversion capability, and one a configurable stereo aux out that can be toggled on/off from the remote for cue or other functions. The remaining three AES3 sends are post-fader (post volume attenuator) to feed studio loudspeakers.

In Use

The good folks at Genelec, pioneers first in powered monitors and later in adding direct digital inputs, kindly provided a full 5.1 all-digital input monitor system for the StudioComm system evaluation: five 8130A two-way loudspeakers and its SE7261A subwoofer with integral bass management. Setup was straightforward: input signals to the AES3id BNCs and AES outputs to the SE7261A and, from there on, to the 8130As, daisy-chaining the front and rear pairs.

I hooked up the system before cracking the manual and had tunes to listen to while I perused the instructions for the finer points of operation and configuration. Operation is largely intuitive; we all know what to do with a volume knob, mute, dim, and solo functions, right? I did take a moment with the input select — four buttons for five inputs, the top button selecting between two “groups” with the surround inputs in the first group and the stereo inputs in the second. I might have preferred that the top button toggle between the two surround inputs and left the remaining three to select between the stereo inputs, but I got used to their paradigm quickly. [According to Studio Technologies, “The buttons are designed such that up to six unique input choices from the two surround (5.1) and three stereo inputs can be configured during setup to address the monitoring needs of the specific application.” — Ed.]

More in-depth setup requires reference to the manual. There’s a recessed config button on the rear of the 77B used to enter configuration mode (setting your reference level, adjusting the pop solo offsets, user settable input delay for audio synchronization with a video monitor, selecting either the left or right of the stereo A/B-left/right inputs to monitor a source where independent signals are being fed, as can happen in a broadcast plant and so on) and for programming the remote control’s various user-settable functions. This isn’t something you’ll find yourself doing often once you’ve selected your configuration.

Having the solo functions on the remote is perhaps my favorite operation feature of the system, and I can see where a broadcast facility would love the pop feature; it allows the user to focus on a particular channel or group of channels while still monitoring the full signal. Broadcasters are going to delight in the ability to monitor with dialnorm parameters applied when listening to content where dialnorm is being adjusted (a program stream with imbedded commercials that have independent dialnorm values, for instance). The only function not included that a user might miss is internal bass management (not an issue in my use, as the Genelec system handles this function quite well). You can downmix a 5.1 signal to stereo and a stereo signal to mono (with fixed and commonly accepted mix coefficients). Though I didn’t discover how to downmix the 5.1 all the way to mono in my trials, according to Studio Technologies, “When monitoring a surround source, pressing the stereo-to-mono button will enable 5.1-to-mono downmixing and simultaneously light both the 5.1-to-stereo and the stereo-to mono indicators.” Recording users may find the AES3id inputs unfamiliar, but in a pinch, you can successfully unbalance an AES3-XLR signal to feed the BNCs.


As for sonics, I’m quite familiar with Genelec surround systems, and the 76DB in no way compromised the monitor system’s performance. Actually, it was a delight to be able to maintain a completely digital chain. The StudioComm 76DB/77B surround monitor loudspeaker control system is easy to implement and amply flexible, transparently performing its intended function while adding enough bells and whistles to enhance the capabilities of most DAWs and digital desks.

Frank Wells, formerly a radio broadcast and recording studio technician is the editor of Pro Sound News and the editorial director of Pro Audio Review.