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Drawmer CMC2

Monitor Controller
Published November 2017
By Hugh Robjohns

Drawmer CMC2

Drawmer’s latest monitor controller puts the same impressive audio quality as their MC2.1 into a new desktop format.

British manufacturers Drawmer have been building high-quality but affordable pro-audio hardware for nearly 40 years now. They continue to offer a range of processors, but in recent years they’ve also turned their attention to active monitor controllers and currently offer no fewer than four different models! I reviewed the very first, the original MC2.1, back in SOS April 2014 (http://sosm.ag/drawmer-mc2-1), and I was very impressed with its genuinely transparent sound quality and the feature set, which ticked all of my (rather demanding) boxes and was more extensive than many other far more expensive alternatives.

Since then Drawmer have added the larger, more capable MC3.1, the minimalist MC1.1, and the surround-sound MC7.1. All models share the same core circuitry as the original. The latest addition to the fleet is the CMC2, the name denoting that this is intended as a ‘Compact Monitor Controller’ for stereo sources, and it sits somewhere between the MC1.1 and MC2.1 in terms of facilities. However, it has a very different — and I’m sure many will think a rather more attractive and practical — form factor.

Overview

As is common these days, the CMC2 is powered by a universal (100-240 Volts AC) wall-wart power module, which provides 15V DC to the main unit. Adapter plates are included for UK, USA, EU and Australian mains sockets, and the PSU is a double-insulated type, meaning it has no mains safety earth connection so will not create any mains ground loops. As a powered, active monitor controller, the CMC2 is completely immune to the frequency response variations that can occur with passive units, is indifferent to source and destination impedances, and can work with long cables if needed.

At around 1.1kg, the main unit is surprisingly heavy for its size, but it’s very compact (183 x 453 x 164 mm). The mass comes largely from its steel base chassis, but it’s necessary to keep the unit stable on a desktop when there are so many cables plugged into the rear panel. Rear-panel socketry comprises nine quarter-inch TRS sockets, plus a coaxial DC power input. All of these rear-panel audio connections are balanced, with outputs for two stereo sets of monitors, plus a mono output for a subwoofer or mono check speaker, and two stereo inputs. The front panel carries a 3.5mm mini-jack socket, which accepts an unbalanced stereo signal from an MP3 player, mobile phone or tablet (etc), and a standard quarter-inch stereo headphone output.

The rear panel hosts the DC power inlet, two pairs of inputs and outputs on TRS jack, and a  mono TRS jack for use with subs or mono-check speakers.The rear panel hosts the DC power inlet, two pairs of inputs and outputs on TRS jack, and a mono TRS jack for use with subs or mono-check speakers.Operationally, things couldn’t be simpler: three buttons in the bottom left corner operate relays to select the inputs (all three can be selected and mixed together, if required), and the Aux (3.5mm) input has its own input sensitivity control. The middle of the unit is dominated by a large rotary volume control with three more buttons above to select the output destinations (speakers A, B and Sub). Again, relays are used for signal switching, and all three outputs can be selected together if desired. The volume control features the same four-gang potentiometer arrangement as the MC2.1, which helps to maintain very close stereo channel-tracking, and the control range spans -80 to +6 dB (unity gain is roughly at the ‘7’ mark on the scale). Below the volume control is a blue LED to indicate when it’s powered up, and a complete Mute button.

Over on the right-hand side is a completely independent volume control for the headphone output, and three more buttons select a polarity inversion, mono sum and level Dim (-20dB). Selecting the polarity and mono buttons allows the Sides, or stereo-difference, signal to be auditioned. All of the buttons have status LEDs (green for the input sources, orange for the output destinations and red for the monitor conditions).

In Use

Operation is, as you’d expect, very straightforward, and the controls feel reassuringly solid and reliable. I like the ability to combine inputs by selecting multiple sources, but the buttons still allow easy A-B source switching when needed. The speaker destination buttons work the same way, again allowing easy A-B switching if required. For monitoring systems operating with a separate subwoofer, the ability to switch it on and off can be very useful, especially in rooms without optimised low-end acoustics, but as this output is a mono sum of the stereo output it can alternatively be used to drive a mono check speaker — a function that I found especially useful.

All controls are located on the top panel, including polarity-invert, mono-check and dim buttons alongside the source/speaker selection and level controls.All controls are located on the top panel, including polarity-invert, mono-check and dim buttons alongside the source/speaker selection and level controls.The headphone output is powerful, although the volume control seems to do most of its work at the low end, and quite large position changes seems to have relatively little effect at the high end. The polarity, mono and dim buttons all apply to both the main and headphone outputs, but the mute and main volume control don't affect the headphones. There are pros and cons for this arrangement. For example, you’re able to mute the main speakers and still use the headphones while recording, although you have to unplug or turn down the headphones when using the main monitors — but there’s no perfect arrangement for all situations, and overall I found this configuration works well enough for me.

One of my pet bugbears is how few budget monitor controllers allow the Sides or stereo-difference signal to be monitored. All it requires is a polarity-inversion facility before the mono sum, and yet it’s such a useful resource. I use it all the time when aligning the gain of dual-mono channels handling a stereo replay source, or for aligning stereo mic arrays, as well as for checking mixes to see what the mono listener will be losing. It’s also frighteningly revealing when assessing the damage of low bit-rate MP3 files! Of my standard set of monitor controller tools, the CMC2 only lacks the ability to mute the left and right outputs individually (although that’s not difficult to work around) and a balance control. Again, it’s surprising just how many monitor controllers lack this facility, even though no two listeners ever perceive the centre of the stereo image to be in exactly the same place! Given the remarkably low price of the CMC2, though, Drawmer can be forgiven for omitting these luxuries.

As a compact and low-price unit, the CMC2 also neglects a few other facilities that are common in larger and more expensive units. For example, there are no output-level trims to balance the volumes of multiple sets of speakers — you’ll need to do that with the speakers’ own input sensitivity controls. Neither are there any input trims to offset the levels of raw and compressed sources to make comparisons easier — although to be fair that function can now be performed automatically with DAW plug-ins such as Meterplugs’ Perception (other products are available...). There’s also no artist cue feed(s), no talkback and no duplicate headphone outputs but, again, for a large proportion of the home-studio market, to which this product is priced to appeal, these functions aren’t required. Personally, I’d much rather have a basic but sonically transparent monitor controller that provides the important monitoring tools — like this one — than one with lots of bells and whistles but which compromises the integrity of the monitoring path.

Verdict

They say the proof of the pudding is in the eating, and so I patched the CMC2 in place of my usual Crookwood mastering console’s monitoring section. I didn’t notice any significant change in sound quality at all. It really is that good — and it did all I needed it to do: I could hear everything I expected and needed to hear, and it performed flawlessly. I also much preferred its desktop form-factor to the upright format of the original MC2.1. Of course, the input and output cabling could conceivably become an issue in some situations, but I have a desk with built-in racking, and I have a 1U ‘letterbox’ to allow external cabling to be brought neatly to the desktop, and this worked very well with the CMC2.

So, if the budget is limited but you need a monitor controller that’s worthy of the name, that won’t damage the monitoring signal and has sufficient facilities to be genuinely useful, and that won’t be outgrown in a hurry, I can heartily recommend the CMC2. Most impressive!

Alternatives

For similar outlay, the TC Electronic BMC-2 offers an elegant solution for digital sources, while the PreSonus Monitor Station V2 has all the bells and whistles for anyone requiring four artists’ cue feeds and talkback, but it lacks some basic monitoring tools.

Test Bench

Running through a battery of bench tests using an Audio Precision test set, I started by measuring a signal-to-noise ratio of 93dB (ref 0dBu). Although the published specifications suggest the maximum input and output signal levels are +21dBu, I found the review model was quite happy to pass +24dBu in and out with only 0.0015 percent THD (even into a 600Ω destination impedance). However, I noticed that the intermodulation distortion — which is extremely low anyway — started to rise slightly when the input level exceeded 12dBu. The AES17 dynamic range figure measured 122dB (A-weighted) or 118dB with a flat response (both ref +24dBu) which is, again, better than the published specs claim.

Crosstalk measured -86dB at 1kHz and -67dB at 10kHz which is good, while stereo-tracking of the main volume control was better than 0.2dB across most of the range, and didn’t exceed 1dB even at the quiet end of the range. The frequency response was ruler-flat to above 80kHz (the limit of my Audio Precision test system), and the -3dB point at the low end was 10Hz (-1dB at 15Hz).

Overall, these are excellent specifications and confirm a clean, quiet and neutral sound character.

Published November 2017