Well-known in studio circles, but perhaps less familiar to sound reinforcement users, Focusrite has a long and distinguished legacy in professional audio. The company was founded 29 years ago by audio legend Rupert Neve (whose circuit designs still grace a number of Focusrite’s products) and four years later, it was acquired by Soundcraft co-founder Phil Dudderidge. After a short bout in the large console market, Focusrite began expanding its world-class signal processing series with a successful line of audio interfaces that were on-time and in-step with the burgeoning studio market.
Seeing the future in audio networking, at Winter NAMM 2011 Focusrite launched RedNet, a professional audio networking system initially intended for the studio market. RedNet is based around Audinate’s successful Dante protocol, which uses conventional IP-based Ethernet switches to carry up to 1,024 channels (512 inputs and 512 outputs) of high-resolution digital audio over a single, standard Ethernet network.
In those three years since the that debut, and with the huge growth of interest in Ethernet- and MADI-based digital audio transport systems for sound reinforcement systems, new Dante-compatible consoles and a number of high-profile users (such as The Killers’ recent tour), Focusrite has been seriously targeting RedNet to the live market. This makes perfect sense — MADI and Dante are well-established and accepted in live sound rigs, and RedNet’s modular approach to hardware allows for a high-degree of customization that is easily scalable and expandable to any size system.
System Basics
The RedNet system is based around both hardware and software (PC or Mac) components. Six rackmount I/O interfaces (logically numbered 1 through 6) are available. The software includes the required RedNet Control, which offers remote control of all modules on the system, including the ability to set parameters such as sampling rates and tweaking mic/line input gains, phantom power, channel linking, HP filter in/out, etc. A Dante Controller application adds advanced routing possibilities using a simple click-assignment matrix, along with some housekeeping functions (device/clock status, etc.).
At the heart of the system is the RedNet PCIe hardware card ($999/street) for creating and controlling larger audio networks with up to 128 I/O at less than 3 ms latency. Smaller systems can be configured without this card, such as using the RedNet 5 or RedNet 6 as a front end, or with other Dante-enabled equipment.
Standard RedNet features include 24-bit resolution at up to a 192 kHz sampling rate, with support of 44.1/48/88.2/96/192 kHz operation, with up to 128 inputs and 128 outputs at 96k Hz. Specs include a 119 dB dynamic range, and all I/O units employ JetPLL technology for ultra-low-jitter performance. Also, all I/O’s are hot-swappable and are automatically detected and configured by the software as soon as they are connected.
One of the advantages of the RedNet system is that it operates on standard, off the shelf Ethernet components. RedNet is compatible with both Cat-5e and Cat-6 cabling, although Focusrite recommends Cat-6 STP, particularly for systems with higher channel counts and high sampling rates. In terms of switches, a “managed” unit designed for use in 1000 Mbps (Gigabit) systems is required. I had excellent results with a Netgear GS108T 8-port Gigabit Smart Switch, which run around $100.
Ins and Outs
Central to RedNet is the variety of I/O interfaces for a range of user-specific applications and installations.
RedNet 1 ($1,999/street) is an analog input/output box, with two standard D-25sub connector, one for eight analog ins and one for eight analog outs, along with a Dante port. Operating levels can be set to +18 dBu or +24 dBu.
RedNet 2 ($2,999/street) essentially doubles the capability of the RedNet 1 unit, with 16 analog inputs and 16 analog outputs, configured on four D-25sub connectors (eight channels on each) and a Dante port.
RedNet 3 ($1,499/street) offers up to 32 digital inputs and outputs, configured with 16 TOSlink optical ports (eight in/eight out) for ADAT S-MUX2 support, stereo S/PDIF in and out on two RCA jacks, eight channels of AES/EBU on D-25sub multipin, word clock in/out sync on two BNC’s and a Dante port.
Probably more core in live sound applications is the RedNet 4 ($2,499/street), which features eight analog inputs, either Focusrite mic preamps via rear XLR jacks or line inputs on a D-25sub connector, as well as two front panel 1/4-inch D.I. inputs, which can be assigned to channels 1 or 2. Each mic input has switchable 48 VDC phantom power and a high-pass filter, and pairs of channels may be ganged for stereo operation. A rear panel Dante port is also standard.
The RedNet 4’s front panel has a rotary gain control (up to +63 dB of gain on the mic inputs) with a numeric display, eight channel select buttons and hardware switches for mic/line/DI selection, phantom power and a -18dB/octave at 75 Hz high-pass filter. It also has LEDs confirming network status, sample rate. There are no meters, but RedNet 4 does provide color LED indicators above each channel for signal presence (green LED for levels above -42 dBFS), a yellow LED for levels reaching -6 dBFS and a resettable red peak LED. Any of these controls are also remotely adjustable via the RedNet Control software, but the availability of these local front panel controls is a definite convenience in a live situation. The front panel labeling under the LEDs is somewhat hard to read in dim lighting; I would have preferred backlit legends.
For many users, one desirable option to a RedNet system comes with the RedNet 5 (street $1,499), a multichannel, bi-directional digital audio interface, that allows an Avid Pro Tools|HD system to be connected to a RedNet network. Any 96 channels from RedNet can be routed in/out of a Pro Tools|HD rig, or 192 channels with a Pro Tools|HDX system. This is based on 48/96 kHz operation; channel counts are halved at 192 kHz. One RedNet 5 unit acts as a 64-channel (32 in/32 out) connection; multiple RedNet5’s can be added for additional channel capacity. And with its bidirectional ability, both recording and show playbacks/virtual sound checking are supported. Word clock input/output connectors let the RedNet5 act as either a master or slave to external digital devices.
Adding connectivity to the system, the RedNet 6 MADI Bridge ($1,999/street) brings together your RedNet-based audio system with the world of MADI. The only single-rackspace interface in the series, RedNet 6 provides the link between Ethernet-based RedNet and MADI/AES10 devices, with bidirectional coaxial and optical support of up to 64 MADI channels (32 channels at 96k Hz and 16 at 192k Hz).
Diving Into RedNet
To get a taste of RedNet, I dove in with a fairly simple system based on RedNet 1, 4 and 5 modules. Setup was a breeze. In fact, much easier than I anticipated, as the words “network” and “ease of configuration” are rarely used in the same sentence. The software package installed easily on my Mac (sorry, I didn’t try the PC version) and system hookup was straightforward, with a few minor caveats. It is recommended that once the Ethernet connections are made, components are powered up in the right sequence, starting with the Gbit switch, followed by the RedNet hardware (one at a time), and then the host computer. One thing to be aware of is that each one of the RedNet boxes can take 30 to 40 seconds to boot, so a large system may take a while to power up.
Once everything’s up, you then launch the RedNet Control software. It scans the network, searching for and displaying any available hardware and by simply dragging I/O devices from the bottom of the screen to the top; they are automatically routed and their inputs assigned in the order stacked. So if you have two RedNet 4 units, the one at the top of the screen is assigned as inputs 1 through 8 and the second becomes inputs 9 through 16. A similar routine applies to the outputs of any units on the network. Once set, clicking on any “routed” unit brings up its virtual panel — which mimics the front view of hardware — and you’re on you’re way. More complicated routings can be handled via the matrix style screen on the Dante Controller software.
With eight preamps in a single 2U enclosure, the RedNet 4 modules are fairly sizeable — 64 channels would require 16 rackspaces, as compared to say, two Yamaha Rio 3224’s that would take up 10 spaces, but also include 32 outputs as well.
The setup procedure and ease of remotely tweaking preamp settings are both definite plusses, but what really counts is the audio performance. This is the major strength of the RedNet system. The sound of the preamps are absolutely pristine, offering clarity, transparency and tons of headroom, and the degree of detail is impressive. Even at a lowly 48k Hz, the stepped-up performance is apparent. The build quality of all the gear is rock solid. I never experience a single glitch or hiccup.
Another point worth emphasizing is the modularity of the RedNet system, which allows users to begin with a more modest rig and then easily build or expand on the system as their needs grow. Combined with its ease of recording direct to Pro Tools and interfacing with MADI, Dante or analog systems, RedNet is one networked audio system that’s expandable, scalable, versatile, easy to use and great sounding. Two thumbs up on this one!
At a Glance
Focusrite RedNet
Versatile and flexible Dante-based audio networking system uses standard Ethernet connectivity and adds excellent preamps and easy to use control software.
Pros: Great sounding; impeccable build quality; modular, flexible and scalable.
Cons: Preamp units are fairly sizeable; front panel labels hard to read in dim lighting.
More Info: focusrite.com
