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Page 2: Focusrite Red 4Pre

Thunderbolt Audio Interface
By Sam Inglis

The Way Out

At the other end of the signal chain, the Red 4Pre offers monitor-control arrangements that are almost identical to those of the Claretts. What this means is that you get a single rotary encoder that can be switched to control the volume of outputs 1-2, 1-4, 1-6 or 1-10, plus Mute and Dim functions. The only significant change is that, once again, everything is now digitally controllable from the front panel, so the dedicated level controls on the Claretts’ headphone outs have disappeared, and everything is done using the rotary encoder.

Monitor control, or lack of it, was one of the more limiting features of the Claretts, so I think it’s disappointing that the supposedly high-end Red 4Pre doesn’t offer more in this department. We are, after all, talking about an interface that’s designed to form the heart of a reasonably upmarket control room. In most such environments, there’s a non-negotiable need for functions such as alternate speaker switching, talkback and mono fold-down, none of which can be implemented either from the Red 4Pre’s front panel or from the Focusrite Control software. Most Red 4Pre owners will thus need to budget for a third-party monitor controller as well. (Perversely, Focusrite actually make a Dante monitor controller called the RedNet AM2, which would presumably be compatible — but it doesn’t have any of these features either!)

Focusrite told me that they do plan to add speaker switching and a mono capability in a future update to Focusrite Control. What’s not clear at this stage is whether these features will be accessible from the Red 4Pre’s front panel — as they should be! — or whether users will have to keep a control panel utility hovering in the background after all.

Latency

As I’ve already mentioned, low latency was one of Focusrite’s key design goals for both the Clarett range and the Red 4Pre. Unusually, the relevant product pages on Focusrite’s web site include comprehensive, detailed real-world measurements of round-trip latency at different sample rates and buffer sizes (and, interestingly, in different DAW programs — it turns out that latency varies a surprising amount with the host software). My ‘early 2014’ MacBook Air wasn’t quite up to running the Red 4Pre at a 32-sample buffer at 96kHz, but with newer and mightier machines, it’s apparently possible to achieve a round-trip latency of 1.67ms in Logic X and Cubase 8, which is extremely impressive. I was able to work at 44.1kHz with a 32-sample buffer, whereupon Logic reported the round-trip latency as 2.9ms. To test this, I bounced a click track as an audio file and then re-recorded it through the Red 4Pre’s analogue I/O. The re-recorded file lined up precisely with the original, indicating that the reported latency was indeed accurate.

Running at these very low buffer sizes does introduce a CPU hit, but it’s a manageable one, and as Focusrite say, it is a liberating experience to dispense with a separate cue-mixing utility. You can apply your choice of EQ, compression and effects plug-ins within the DAW’s mixer window, and keep them in place for final mixdown, just as Pro Tools TDM and HDX users have always been able to do. You can track live using virtual instruments and guitar amp simulators without any compromise in feel. And you can be confident that what you’re hearing is what’s going to disk. I like Focusrite Control, but I like doing without it even more.

At the heart of the Dante Controller is this routing matrix. Here, the outputs from a RedNet 4 are being routed to the Red 4Pre.At the heart of the Dante Controller is this routing matrix. Here, the outputs from a RedNet 4 are being routed to the Red 4Pre.

On The Net

So that we could test the Dante expansion, Focusrite sent over one of their RedNet 4 eight-channel preamps. Adding extra I/O to a Red 4Pre this way requires more than just connecting the units with an Ethernet cable and choosing the appropriate sync option, though. The host computer also needs to be connected to the network, and needs to be running Audinate’s free Dante Controller utility. This is compatible with Mac OS 10.8.5 and later, and with Windows 7, 8 and 10 (though there aren’t yet any Windows drivers for the Red 4Pre itself). At base sample rates, the 32 Dante channels show up in your DAW as inputs 29 and up. Fewer ADAT channels are available at 96kHz, so the Dante channels move down, numerically speaking, to close up the gap.

Dante Controller doesn’t make too many concessions to user-friendliness, and its interface is littered with jargon that will probably make more sense to IT professionals than musicians. What’s more, the Red 4Pre manual pretty much washes its hands of telling you how to set up Dante expansion, when a friendly walk-through would be very welcome. However, although I quailed inwardly at terms like ‘leaf nodes’ and ‘multicast bandwidth’, it took surprisingly little blind prodding with the mouse before I was up and running. A little experimentation is needed to achieve the best configuration for your complement of I/O, and no doubt things can get a lot more complicated if you need to incorporate multiple converters, switches and so forth, but in the long run, this is the sort of configuration you can set and forget.

Who’s It For?

The inclusion of Dante and Pro Tools HDX compatibility places the Red 4Pre within an interesting and sparsely populated sector of the market that lies in between the established professional and project-studio paradigms. In other respects, it could be seen as a rival to upmarket project-studio interfaces like Apogee’s Ensemble Thunderbolt or Universal Audio’s Apollo 8p; and, considered as self-contained devices, both of those products are undeniably more complete than the Red 4Pre. Both offer similarly excellent audio specs, more mic preamps and better monitor control, and you also get Powered Plug-in support in the Apollo and neat guitar re-amping features in the Ensemble.

However, what neither the Ensemble nor the Apollo offers is the same potential for expansion, and it’s the extra connectivity that plants one of the Red 4Pre’s feet firmly in the pro world. There is still a bewildering range of competing audio-over-Ethernet protocols out there, but Dante looks like it’s here to stay, and in the case of the Red 4Pre, opens up possibilities that simply aren’t there with ADAT. Long cable runs are unproblematic and cheap to install, and multiple devices can be attached to the network in a mind-boggling array of configurations. You could, for instance, use it to set up an array of remote-controlled preamps, stage boxes and personal monitor mixers or headphone amps in the live room, or hook into a live-sound console located elsewhere in a studio/venue complex.

The main rival for the Red 4Pre’s role as the hub of such a system is probably MOTU’s new range of Thunderbolt/AVB-based interfaces, such as the 1248. Unlike the MOTU units, however, the Red 4Pre is also a unique and cost-effective means of adding lots of I/O to a Pro Tools HDX system: a single Red 4Pre unit combines much of the functionality of an Avid Omni I/O with as much digital connectivity as you’d get from two or more HD I/O units. I’ve no doubt Focusrite will sell lots of them into this market, especially as there are presently few other options for getting audio from a Dante network into a Pro Tools HDX environment. Outside of the HDX world, it remains to be seen whether there is a significant gap in the market between the kind of project studio for which 16 or 24 inputs and outputs are plenty, and the high-end, multi-room suites that might employ more scalable systems — a full-blown Dante rig like Focusrite’s RedNet, or the Waves/Digico Digigrid range, for example — but for anyone whose needs do fall into that gap, the Red 4Pre has to be a leading contender.

Synchronicity

The Red 4Pre is unusual in that it bridges the worlds of networked audio and conventional interfacing. It presents a single list of inputs and outputs to your recording software; all of these are ultimately streamed over Thunderbolt, but they are sourced variously from the Red 4Pre’s own converters, from the Dante network and from the ADAT and S/PDIF connectors. Compared with the Red 4Pre’s analogue I/O, audio from digital sources incurs a small amount of extra latency: A-D or D-A converter latency in all cases, plus the ‘device latency’ added when the Red 4Pre (or any Dante ‘receiver’) is connected to the network. This is configurable in the Dante Controller application, and can be anything from 5ms down to less than half a millisecond. I had no problem running it at 1ms or lower, which doesn’t compromise the overall round-trip latency very much. However, it’s worth noting that the Red 4Pre doesn’t compensate for the latency of the Dante network and converters, or report it to the host computer. And like any interface with digital I/O, it can’t know about the converter latency that ADAT or S/PDIF expanders might add.

What this means is that in a fully expanded Red 4Pre rig — ie. one featuring both Dante and ADAT expansion — there are likely to be three sets of inputs and outputs that are, at best, a few hundred microseconds out of sync with each other. This is probably something you can ignore in most circumstances, but if you were multi-miking a single source, you’d certainly want to avoid splitting those mics between the different types of input. Likewise, if you were using a combination of different types of I/O to send out individual channels from a big session for mixing on a large-format console, you would want to make sure all your drum tracks were emerging via a single route, rather than being split across internal and expansion outputs. It also raises the potential for issues to arise when using external hardware processors as inserts within a DAW mix. This contrasts with something like a Pro Tools HDX system running only Avid interfaces, where converter latency is fully compensated.

Red 4Pre & Pro Tools HDX

Focusrite’s marketing suggests that they see the Red 4Pre primarily as a Thunderbolt audio interface for use with native recording and mixing software. To my mind, though, perhaps the most interesting move they have made with this unit is to add a pair of mini-Digilink connectors on the rear panel. Focusrite have a long history of collaboration with Avid, but this seems to me a significant new development, making the Red 4Pre the first Focusrite device I know of that can be operated as a Pro Tools HDX or HD Native interface. What’s more, whereas the Red4 Pre definitely occupies the upper end of the price range for native interfaces, it represents a comparatively cost-effective way of expanding an HDX or HD Native system, given that a single Red 4Pre presents up to 58 physical inputs and 64 outputs to a Pro Tools rig.

By way of comparison, the Red 4Pre is conceptually similar to Avid’s own Omni I/O, but, with the exception of its limited monitor control features, offers more in almost every department, at a slightly lower price. The Omni I/O owner who wants to gain more than eight inputs and outputs without leaving Avid-world would need to add some variant of the HD I/O unit, at a cost of several thousand pounds; the smug Red 4Pre owner can simply plumb in ADAT- or Dante-compatible converters and preamps. And for those who need vast amounts of I/O, up to three Red 4Pres can be connected for a total of 174 ins and 192 outs, at a price which makes it a very tempting alternative to other options such as Avid’s HD MADI. Not owning an HDX rig, I wasn’t able to test this, but the Red 4Pre is definitely worth investigating if you are in the market for an HDX-compatible interface.

Parallel Lines

The “uncompromised” design philosophy employed in the Red 4Pre sees Focusrite’s engineers achieving impressive audio specifications by employing dual converters in a ‘parallel path’ configuration. The idea behind this is that if you run the same signal through two converters simultaneously and sum the output, the wanted signal will be coherent but the noise won’t; so summing the two paths together will increase the level of the wanted signal by 6dB, compared with a 3dB rise in the noise level. Running two converters in parallel thus allows the signal-to-noise ratio to be raised by 3dB. In theory, you could double the number of parallel converters over and over again to get further 3dB improvements, but obviously, it’s not practical to do this too often.

Sweetening The Deal

The Red 4Pre doesn’t ship with any bundled recording software, which makes sense, as I’d imagine any potential buyers would already have a favoured DAW. What you do get, though, is a nice plug-in bundle. Fittingly, this includes emulations of Focusrite’s own Red 2 equaliser and Red 3 compressor, while a tie-in with Swedish developers Softube permits the inclusion of the four products that make up their Time & Tone Bundle: the very nice TSAR-1 reverb and Tube Delay, Saturation Knob, and the new Drawmer S73 mastering compressor.

Pros

  • Excellent audio quality and technical specifications.
  • Impressive low-latency performance means there’s no need for a separate cue-mixing utility in most cases.
  • Fully controllable from the front panel.
  • Expandable to a total of 58 physical inputs and 64 outputs.
  • Dante offers flexible expansion options with long cable runs.
  • Potentially a very cost-effective way of expanding Pro Tools HDX and HD Native systems.
  • You get a Thunderbolt cable!

Cons

  • The built-in monitor control is too basic for the Red 4Pre’s intended roles.
  • Most of the analogue I/O is on D-sub rather than full-sized connectors.

Summary

Focusrite’s “best interface ever” provides impeccable sound quality. In terms of built-in features, other Thunderbolt interfaces arguably offer more at the price, but few can match its potential for expansion.

information

£2099.99 including VAT.

Focusrite +44 (0)1494 462246.

sales@focusrite.com

www.focusrite.com

Published May 2016