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Crookwood C2

Monitor Controller
By Eric James

Crookwood C2 monitor controller.

This new monitor controller compares well with the competition — in terms of both price and quality.

Dedicated studio monitor control is a relatively new, but rapidly expanding sector of the studio equipment market. There's no mystery about this development: even assuming that most mixing, and even mastering, work is now done 'in-the-box', there is still a need for some way of converting the resulting digital signal to analogue, and then of controlling (ideally in a measurable and repeatable way) the gain going into power amps or to powered monitors. Traditionally this has been achieved with outboard mixers and maybe a stereo D-A converter but, with the other 'traditional' tasks of the mixer being taken over by the DAW itself, it has begun to make sense to shrink the mixer to something like a master fader, with maybe the choice of just two or three inputs. To serve this need, companies such as Cranesong have produced high-quality monitor controllers, in their case the Avocet, which has a couple of analogue and digital inputs, a stepped level control and an excellent internal D-A converter (see Hugh Robjohns' review in SOS November 2005).

However, even with the rise of high-quality plug-in processors that can rival the performance of stand-alone units, there is still sometimes a need to integrate certain outboard processors that have no plug-in equivalent: perhaps because they are analogue (many mastering engineers, including me, still swear by the warmth of analogue compressors, such as the Manley Vari-Mu or the sweetness of analogue EQs such as those by Cranesong or Avalon); perhaps because they are digital and somehow unique (for example, the TC Electronic TC6000 and the Weiss DS1, whose compression algorithms have no plug-in counterparts of equivalent quality); or perhaps for some other, more-or-less voodoo, quality. Such a setup requires that a digital router be added to the monitor controller, to allow the digital processors (and the analogue chain, bracketed by its converters) to talk to each other.

This is the situation in my own mastering and editing facility, where I've recently installed a Crookwood C2. I had previously used a Z-Systems 16.16r Digital Detangler to connect and route digital signals (DAWs, external processors, and other digital devices such as DAT, DTRS or Alesis Masterlink), feeding the signal for conversion and monitoring to an Avocet. It worked very well, but the Z-Systems device operates on a number system for identifying the processors. So, although repatching from the remote controller was simple enough once (or if!) you'd remembered whether the EQ was on channel six or seven, and though you could store in memory certain regularly used routines, it was not quite optimum, especially if you wanted just briefly to 'tap' the signal at any point in the processing chain, or even quickly switch the order of the processors. This may sound like a relatively minor point, but it's a simple fact that the willingness of an engineer to experiment is inversely proportional to the ease of doing so, and that means that useful alternatives are sometimes left untried because it is simply too much hassle to do so.

Then, earlier this year, when some changes in my equipment setup (such as taking 'inboard' some of the previous outboard processing) meant that the 16-channel router was a little more than I needed, I began to think about a solution that combined a smaller but more easily reconfigurable digital router with a first-class D-A converter and monitor controller. Along came Crookwood, with their new C-series monitor controllers.

Some Crookwood Background

Despite being relatively unknown in their home country, Crookwood's combination of software routing control and analogue processing has attracted highly prestigious clients in Europe and the USA for over a decade. One of the great names in Mastering, Glenn Meadows, then at Masterfonics in Nashville, was an early adopter of Crookwood mastering consoles, as was David Glasser of Airshow Mastering, and just recently Bob Katz has bought a system for his 'B' room at Digital Domain, which has more complicated routing and monitoring needs than his main mastering room. With very little fanfare, then, Crookwood products have been active somewhere in the chain (from mic-pre to mastering consoles) on a fair number of Grammy- and other award-winning productions.

Founder Crispin Herrod-Taylor had worked as a design engineer with some of the best-known companies in UK pro-audio, including Meridian, SSL and Focusrite, before setting up Crookwood 15 years ago at a base in rural Wiltshire (the company is named after a farm near where Crispin grew up). His first products were the oddly-shaped but very well regarded 'Paint-pot' mic pre-amps and mastering 'Bricks', followed by large mastering consoles which attracted the attention of the American engineers. The C2 unit under review here is one of a new range of four controllers intended to enable more modest-sized companies, or individual engineers, to use Crookwood designs in their facilities.


The C2 Monitor Controller is the smallest of the Crookwood range, combining a remote-controlled, analogue monitor control system with two analogue inputs and an 8 x 8 digital router. It has three analogue outputs: two on balanced XLR for connection to powered monitors (or power amps); and a headphone socket with standard quarter-inch stereo connection. The controller comes in two parts. One is a rackmount 1U 'brain', which contains all of the processing software, the analogue relays and the D-A converter. The other is a remote-control panel (which can be either rackmounted or housed in a nice wooden desktop pod), which is data- and power-connected to the brain by a single five-metre cable (VU Meter and Talkback panels are available as cost options). The brain connects to the rest of the studio using four Tascam-spec D25 sub-connectors that break out to cables terminated in XLRs. The break-out cables can be ordered at any reasonable length and I chose 1.5 metres, allowing the Crookwood to connect directly with my processing rack.

Most of the hard work is banished to the discreet-looking rack unit, which connects to equipment via the D-Sub connectors on the rear.Most of the hard work is banished to the discreet-looking rack unit, which connects to equipment via the D-Sub connectors on the rear.Connecting the C2 is fairly easy, as Crookwood supply a clear pin-out table (although it's pretty obvious that digital in and out number 1 go to unit number 1, and so on, the analogue connections are slightly more complicated). The only exception is that if an external D-A converter is used, it is wired from output 1, but if the internal D-A is used, this output becomes non-functional. This means that it is not possible to have the internal and an external D-A converter wired into the unit through output 1 at the same time. There is a workaround for this, which sacrifices one of the other digital outputs and uses one of the analogue inputs, but it is unlikely that anyone would want two D-As available at the same time anyway. In fact, as we'll see later, unless you have an absolutely first class external D-A at the level (and price!) of Prism or DCS, you'll be very happy with the Crookwood internal converter.

Although the C2 comes with a dedicated headphone output, because I like to use Stax earphones that have their own driver, and because there is only one set of monitors in my setup, I connected the 'main spk' output to my power amp and the 'mini spk' to the Stax driver, and left the headphone socket unemployed. One neat feature is that the last used audio level is remembered, so switching between (for example) the main speakers and headphones doesn't require any further alteration of the level control. Of course, given that my Stax driver has its own gain control and so requires a constant-level signal from the C2, this feature is a real boon for me.

The left-hand side of the remote controller is divided vertically into two sections. The top half (the analogue monitor controller) contains the buttons that enable you to select the output, cut either channel, send a mono signal from either channel to both channels, and reverse the phase on the 'L' channel. The bottom half is the digital router. On the right-hand side are the overall level-control knob and four buttons, marked Enable, Option A, Option B/Dim and In/Mute. The Enable button allows for up to 6dB trim control on any selected source; Option A is used to select a digital destination (more on this below); Option B dims the speakers by a set amount (which can be adjusted by the level control, when selected); and In/Mute is an overall system mute. At startup, the system goes through a relay-checking procedure and the C2 defaults for safety to Mute condition and a -96dB output level.

Once all the connections have been made, you can download a Word template from the Crookwood site which enables you to print up and insert into the control panel a label that identifies each button's processor.

In Action

Let's consider a case where we want to master a completed stereo mix by running it through a series (literally a series) of outboard processors. Clearly, this is a mix that needs a lot of mastering help! The route is as follows: DAW outputs 3&4 / DCS 974 upsampler / Weiss MkII digital EQ (incidentally, the most transparent processor to add gain if required) / TC Electronic 3000 digital reverb / DCS 954 D-A / Cranesong Ibis analogue EQ / DCS 904 A-D / TC Electronic 6000 for compression and brick-wall limiting / DAW inputs 1&2 for PQ coding and POW-R dithering for Red Book (audio CD) and DDP (Digital Data Protocol) production, and concurrently to the monitor D-A. It is, of course, possible to monitor from the DAW itself, but for a number of reasons I prefer to monitor by using the C2 to send a parallel signal from the last processor in the chain.

All you need on one screen: the digital destination (DD), and the trim (T) and monitor (Mon) levels).All you need on one screen: the digital destination (DD), and the trim (T) and monitor (Mon) levels).The upsampler takes us from 24-bit/44.1kHz to 24-bit/96kHz; then the A-D converts for recapture at 24-bit/44.1kHz, so the 'downsampling' actually takes place in the conversion, which seems to me to work very well.

With all of the processors patched into and out of the Crookwood, setting up the communication lines between them is very simple. Press the Option A button and, at the same time, press the button you intend to be the destination. When you let go of those buttons, the destination will be shown on the digital readout. Then, to choose a source for that destination, simply press the button of the required processor. Setting up a chain, then, is simply a matter of starting at the final destination(s) and working backwards, so: choose DAW 1&2 as destination and TC6000 as source, then TC6000 as destination and DCS A-D as source and so on... In this setup, the A-D converter does not have a digital source, so the Crookwood 'sees' the analogue chain as one unit, with the D-A and the A-D serving as the in and out. In the above example, the A-D is the source for the TC6000, but then the D-A becomes the destination for the next processor down the line (the reverb).

If system clocking is to be achieved using the embedded clock on the AES signal, the processor routing has at first to follow the clock route, but once this is established you can select digital sources and destinations at will, with no re-clocking required. In my system, the clock source starts halfway round the chain at the A-D converter. It sounds odd, but it makes sense to locate the master here, both because it is the most critical point for clock accuracy (to avoid jitter affecting the programme signal) and because the converter I use has a very stable, high-quality clock.

One-button Flexibility

The flexibility of the Crookwood C2 now begins to show itself. Suppose I am monitoring the whole chain of processors, and I wonder if I might be over-egging the Weiss EQ (placed, in this example, at the start of the chain to be used for 'surgical' processing, with musical 'smoothing' being left to the Cranesong analogue EQ). I have two choices: I can hard-bypass the Weiss to hear what the chain is like with it taken out; or I can press the Weiss button on the controller to send that directly to the output (the routing change sounds instantaneous, but there is actually a microsecond delay, as the output mutes while the new source is engaged). Because all of the other routing is unaffected by this, all I have to do to return to monitoring the full-on chain is select the last processor in the chain as source again. Of course, this works for any processor in the chain, and such one-button flexibility soon leads to more efficient working practices. If any processor does not have a hard bypass (such as a pesky compressor that I am currently also evaluating for SOS), this can be worked around with a two-button bypass routine using the C2. With repatching being so easy, you are more likely to experiment with processing order.

Sound Quality

The sound of a monitor controller comes from two things: the quality of its internal D-A conversion and the purity or otherwise of its analogue path. A few months ago, I was able to compare the Crookwood with the Cranesong Avocet, taking their internal D-As out of the equation by using an external converter. The results of this quickly switched test (available on my company web site at were very interesting. It's a bit like comparing apples and oranges, given that, apart from their gain-control sections, the two units have very different functions (for example, there is no routing on the Avocet) but the sound of both was superb. Comparing both to the D-A alone (a DCS, which has an internal digital output attenuator) the Avocet had a slightly warmer sound in the upper mids and the Crookwood slightly more weight lower down, but even this seemed sometimes to depend on the source material. There was no regularly discernible difference — which speaks volumes for the quality of both units!

A more realistic comparison would be between both units operating with their internal D-A converters. Although I wasn't able to perform such a direct test (once the Avocet was out of the system and the Crookwood plumbed in it simply wasn't feasible to switch them), my impressions were pretty much the same. The Crookwood D-A is excellent: it is the same kind of jitter-immune design as the Avocet and the Benchmark DAC1, and gives the same kind of highly-detailed, tonally-accurate results. There are differences between the three, but for the range of material covered in a normal studio they are pretty minimal. The bottom line here is this: if you have a Benchmark and you are thinking of buying a Crookwood C2, you could sell the Benchmark to help fund it, and you won't notice the difference.


Is there anything not to like? Some kind of patch memory would, as I mentioned earlier, be useful. But I can't criticise: when I mentioned it to Crookwood they promised to incorporate the ability to recall the last setting before power-down in all production models.

The C2 gives you a slice of the very high end of pro-audio quality. It does exactly what you want it to, and does so better than anything else I can think of. The combination of digital router and analogue monitor controller makes it unique at this price point, and it will more than likely replace the Z-Systems/Avocet combination in my own facility, a fact that makes its price seem even more reasonable. 


If you're considering a new monitor controller in this sort of price bracket, you may also want to look at the Benchmark DAC1 (reviewed in SOS July 2005) the Cranesong Avocet (SOS November 2005), the Dangerous Music ST/SR (SOS January 2007) and the Audient Centro (SOS February 2007).


  • Extremely flexible, easily configured, glitch-free digital routing.
  • Top-notch D-A and analogue monitor control.
  • Not inexpensive, but excellent value for money.
  • Real human support, both before and after purchase!


  • There are none at this price.


£1762 including VAT.

Crookwood +44 (0)1672 811649.

+44 (0)1672 811650.

Published August 2007