Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now


Harris Acknowledges the Little Guy

Compact StereoMixer digital Mixer Is Also Big on Features

Compact StereoMixer digital Mixer Is Also Big on Features

It always amazes me what can be squeezed into a chassis these days.

I have to admit that when I first opened the box on my new digital Harris console, I felt a bit like the guy in the old AMC Gremlin commercial from the ’70s: “Hey, where’s the rest of your mixer!?” That may be a bit of a stretch, but like him I became a believer.

The footprint of the mixer – its full name is written as the “Harris StereoMixer digital,” complete with italicized, lower-case “digital” – is only 16 inches wide by 17 inches deep and only 4 inches high. This is good news for a smaller station, or a larger station that needs to fit in just one more small production room. In fact, Harris targeted smaller markets with the SMXd, according to Rich Redmond, director of broadcast systems for Harris’ BCD Radio Broadcast Systems unit. The mixer was designed for Harris by its PR&E division.

One of the difficulties in designing and bringing a small-format mixer to market is deciding which features to cut in order to make the price point; but it doesn’t seem like much has been cut or even overlooked. I’ll touch on the highlights.

Switching channels

The SMXd has seven input channels. Channels 1 through 4 are analog, each switchable between +4 balanced or -10 unbalanced operation. Channels 5 through 7 are digital (AES-3). The digital inputs feature integral sample rate conversion, accepting rates from 32 to 48 kHz. All digital I/O is 24-bit, and internal sample rate and output sample rate is 48 kHz. Maximum analog input and output levels are 24 dBu. External monitor and talk inputs are included.

Channels are stereo (line level for analog channels) except for Channel 1, which is mono; and configurable for a pre-amplified talent microphone. A Talk button and associated output is provided for Channel 1 only. Channels 2 and 3 can be setup for mics as well, and mic channels can be configured to mute the monitors when on. Any one of the inputs can be set up for use with a telephone hybrid or codec, and a mix-minus is provided, both analog and digital.

Each channel has illuminated Program 1 and Program 2 bus buttons, a Cue button, a 100 mm fader and a single illuminated on/off switch. The headphone and monitor controls also each have a fader and common source selection buttons. The on/off switch has a clear removable cap, making channel ID labeling literally a snap.

Balanced +4 analog outputs are provided for Program 1 and 2 busses, monitors, mix-minus and talk outputs. AES3 outputs are provided for Program 1 and 2 and mix-minus outputs. An end cap-mounted headphone output has its own fader, as does the monitor output. The mixer’s meter bridge in addition to housing the LED PPM/avg meters also has an auxiliary front-panel TRS input for Channel 4.

Clean uncluttered UI

Solid design and construction

Comprehensive feature set

Compact size


Unsecured power supply DIN connector

No logic stop pulse

Testing configuration: EV RE-20 mic; Grace Design 101 mic preamp; Telos One Hybrid; Tascam MD801R MiniDisc; PC with LynxOne soundcard using AES I/O; Dynaudio BM5A monitors


SMXd Tabletop $3,695

SMXd Rackmount $2,995

CONTACT: Harris Corp. in Ohio at (800) 622-0022 or visit
I/Os on the SMXd are located on the unit’s rear panel except the talent headphone output and aux input. It sports silk-screened legends for channels, audio and logic connector pinouts, making cabling and installation easier.

Digital and analog audio and logic I/O use AMP mod IV crimp connectors, with the exception of the start pulse and timer reset output, which uses a DB15 connector. An ample supply of pins and housings is included with the mixer, but you will need to obtain the proper crimper, as one is not included with the mixer.

The power supply accepts 95 to 264 VAC at 50 or 60 Hz. It is a relatively large line lump that connects to the mixer via a 5-pin DIN connector. The connector fit is a bit loose – I’d like to see a connector with mounting screws or some type of strain relief. Proper cable management and mixer installation should prevent problems. A grey aluminum cowl is included for covering the back-panel connections and provides a sleek finished look.

Comprehensive logic I/O is provided in the form of talk and warning tallies, as well as start pulse and timer reset outputs. Tally output closures are active as long as the associated functions are, i.e. talk and mic on; while start pulses and timer reset are momentary (250 ms) closures. Unfortunately there are no stop pulses provided. External talk input also is present, and an optional Harris mic panel is available to control Mic 1 remotely.

The SMXd is sturdily constructed using thick-brushed aluminum for the mixer surface, side rails, hand rest and meterbridge. The end caps are cast with a durable gray enamel finish. Removing three screws on the back of the meterbridge and lifting the top allows access to two banks of DIP switches used to configure channels for microphone or hybrid/codec use, as well as various metering options.

In use

This little mixer is big on features, but unlike most feature-laden equipment the user interface is about as simple and easy to use as you can get. The spare number of controls belies the amount of thought that went into the design.

Simple things mean a lot. The meters and the faders are calibrated in dBFS, and the faders are marked with a red line at approximately -12 dBFS. This serendipitously corresponds with the reference level where I work. If desired, both peak and average levels can be represented on the meters (this is the default configuration), and the threshold of the bright blue peak indicators is user-configurable to light at 0, -2, -4 or -6 dBFS.

The meters follow the monitor source selection of Program 1, Program 2, and External or Cue busses; and are large, bright and legible from almost any angle. Even the hue of the green LEDs is pleasant. The rest of the indicators and controls are bright and ergonomic and provide good feedback to the operator. For example, the channel configured for hybrid use blinks its bus assignment button to indicate from which of the two main busses the mix minus is being derived.

During the couple of months I was able to use the SMXd I had the opportunity to see how it performed with a variety of sources. It never disappointed.

The sample rate conversion works like a charm – MiniDiscs recorded at 44.1 kHz and input via AES-3 input to the mixer were converted on the fly. Logic control was easy to set up; turning on the hybrid with its associated Channel On button was as simple as making an interface cable. Audio quality is excellent and the unit is quiet. Fader travel is smooth and has a solid feel. The buttons also seem robust and should last many years.

The folks at PR&E and Harris have built a great small mixer with the StereoMixer digital. Clearly intended for smaller stations, its comprehensive feature set and relatively reasonable cost should make it a first choice for engineers of both smaller stations and larger ones in need of a compact mixer. At $3,695 list, the SMXd is not exactly cheap, but when you take into account all of the features, the build quality and the performance of the unit compared to other small format consoles the SMXd holds its own. A rackmount version is also available.