Over the past 20 years, digital technology has had an impact on every aspect of the recording industry, totally revolutionising the way in which studios and mastering suites produce recorded sound. Long gone are the days of having to take out a second mortgage in order to buy a Fairlight or Synclavier, and as the price of silicon falls, samplers and digital effects units have now become common tools in even the most basic of recording systems. Cheap digital recording is now also a reality, with machines like the Alesis ADAT and DA88 digital 8-tracks still firmly at the top of the equipment sales chart. The rise of the DAT tape, despite falling flat on its face as a basic consumer product, also looks set to relegate analogue mastering to nothing more than a safety backup.
Despite all these technological miracles, any studio is still only as good as the weakest link in its audio chain. Without fail, virtually every signal recorded and replayed during the production process has to pass through the humble mixing desk, and in most situations, this has meant a return to analogue. Digital mixing is still in its infancy, with the major players like Neve and SSL still holding all the cards, and charging like the Light Brigade for a system that will keep your precious audio signals well and truly in the digital domain.
However, the dream of an affordable digital mixing system has now come one step closer, with the release of Yamaha's flagship new console, the ProMix 01. Analogue inputs are still the order of the day, but the new desk offers high-specification analogue to digital converters on each channel, and from then on all of the audio processing -- from level and panning to equalisation and master output -- occurs digitally. The resulting sound quality should, in theory, be hiss-free -- no more pushing up the stereo faders with all of the input channels muted and hearing that tell-tale rise in noise that is associated with normal analogue consoles.
After its triumphant launch at this year's APRS, Yamaha have kept us waiting for the first proper shipment of desks into the UK, but at last the first stock has arrived, and I was eager to put the ProMix through its paces and see if all the surrounding hype was justified.
The ProMix 01 comes in a relatively small package, belying the power contained beneath the bonnet. There are 16 mono input channels, each with a master fader, effects send and equalisation, as well as one stereo input fader, one send/return fader, and a master stereo output control. Each channel has a 'pad' switch, which will attenuate the input signal by 20dB to cope with high-level signal sources, as well as a rotary master gain control to fine-tune the input level. A 48 volt phantom power supply is provided for condenser microphones, but this is not controlled on a 'per-channel' basis; instead, a single switch routes the voltage to all of the first eight inputs. With this design, care should certainly be taken during sessions, as it is possible to damage inappropriately wired dynamic microphones and DC-coupled electronic circuitry.
The front panel is dominated by a 240 x 64-dot backlit LCD display which shows the current setup of the desk, or the individual channel settings, more of which later. A group of key switches to the left of the display act as 'function buttons', determining the overall desk configuration and governing the views that are available on the LCD. Each individual channel also has a 'select' button, which assigns it as the channel to be edited, and an 'on' switch, which routes it to the master faders. Somewhat surprisingly, there are no 'solo' buttons, so if an individual signal needs to be monitored on its own, all other channels have to be switched out and re-instated after editing, although it is possible to monitor individual signals or groups of signals using the more complex 'cue' button on the front panel. There is a '2tr' switch, primarily designed to route a stereo master signal to the loudspeakers, to monitor a final mix direct from DAT or tape mastering machine, as well as a rotary monitor output control for speaker volume, and a headphone level control. A single stereo 'bargraph'-style LED display (12-segment) is provided for monitoring master output levels, as well as the ubiquitous Yamaha data wheel and cursor keys, to move about the display and adjust parameter values.
The rear of the unit contains all the relevant connections the ProMix needs to talk to the outside world. Inputs for channels 1-8 are standard XLR sockets, wired with pin 2 as hot, and channels 9-16 have stereo balanced jack sockets, though the nature of the balanced audio signal will allow mono jack plugs to be used in these channels without a problem. The inputs can cope with a broad range of signal levels, from -60dB to +4dB, and should be fine for the majority of applications. Phono-style plugs are provided for the 2-track input monitor, and unbalanced jack sockets are used for the single stereo channel on the desk. It's particularly handy that when no plugs are inserted into these 'stereo in' sockets, the 2-track input is automatically routed to the main stereo input channel, allowing EQ to be applied to the stereo signal for simple processing of a final recording. The phantom power switch is located on the rear, as are the master power switch, and the mains supply (which is hardwired directly into the back of the unit). Stereo output is via XLRs and phono sockets for the analogue signal and a single phono socket for the digital (which is to the SP/DIF format, suitable for most DAT recorders and digital editing systems). The monitor output, for studio amplification, is routed through unbalanced jack sockets, and there are also two external auxiliary sends, again on jack sockets (though the desk has another two internal effects sends, giving four in total). Standard MIDI In, Out and Thru connections are also provided. It seems a shame that so many mixing desk manufacturers choose to place their headphone sockets on the rear of a console; Yamaha have not broken ranks here, having placed the ProMix's headphone monitor output rather inconveniently next to the mains lead.
So far, I have only touched on how the ProMix is specified as a basic mixing console -- number of inputs, number of auxiliary sends, and so on. Even with these specifications, given the digital processing and output, the desk would surely offer value for money. However, remember that this is also a fully automated audio system. Virtually every single parameter, from channel level to mid-boost EQ frequency, is accessible via MIDI control messages, allowing complete control over every aspect of the mix when a suitable sequencer is used (see the box on automation). Complete mixer setups can be stored internally as 'snapshots', to be recalled for later use, and mixes can be 'played' into a suitable MIDI storage device, so that they can be run again at will, or edited move by move. The ProMix is also equipped with moving faders -- motorised level controls that automatically adjust to a MIDI control level, or lock and move in sympathy with other master controllers. And as if all this were not enough, Yamaha have chosen to add a further two internal effects processors, configured from auxiliary sends 1 and 2, which offer a number of different effects programs, all of which can be adjusted by the user.
The desk is primarily a 'mix machine', with no record busses to route signals to a tape machine, although it is always possible to use the two external effects send for this purpose. Aside from the channel on/off, pad switches and master gain controls, most of the other functions of the desk are controlled using separate function keys and the data wheel. The ProMix works on the principle of viewing one channel at a time, reducing the number of controls that are available (rather than attempting to show every single setting at once), and individual channels are selected using a 'select' button, positioned above each fader. Once selected, that channel becomes the one currently being examined or edited. Every setting, from phase control to EQ, can then be viewed on the LCD display, or adjusted using the program controls. The bottom four function keys, to the left of the display, control the EQ of any channel, which is divided into the standard three main bands of low, mid and high and offers a surprising amount of control across the frequency spectrum. Each band is fully parametric, with a variable 'Q' control (determining how 'tight' a specific cut or boost is, based around a chosen frequency). The EQ is conventionally configured, with a shelving high and low band, and a peak mid section, though it is possible to configure the high and low sections as peaking types. A graphical representation of the cut and boost is shown in the LCD display, as are specific frequency and decibel values. Frequency ranges are very generous and extremely accurate (the benefits of a digital system, no doubt), covering the whole spectrum between 32Hz and 18kHz. The desk is even shipped with 30 preset EQ settings (similar to the sort found on some stereo hi-fi equipment --'Stadium', or 'Large Hall', for example), and there's room for another 20 user settings to be stored. Some are surprisingly good, and all are useful if a mix begins to stagnate and a fresh source of inspiration is required.
Each channel has a programmable phase reverse switch, and all feature comprehensive level metering over and above the master output levels displayed by the built-in bargraph meters. The LCD display can be used to monitor the levels of the 16 input channels, as well as the stereo inputs and effects send and returns. Peak hold is also available to show the extreme transients.
One of the real bonuses of having motorised faders is the ability to 'pair' or 'group' faders. To take a simple example, if a stereo signal is plugged into two input channels, their associated faders can then be 'paired', so that moving either one of them will automatically move the other by the same amount. The signal stays locked, with perfect stereo levels, and only a single fader needs to be moved to adjust both channels. Yamaha have taken this concept one stage further, by allowing groups of any number of faders to be linked in this way. Four different groups are available, and each can be assigned to any or all of the input faders. Moving any single fader will move all of the others within the same group. Another nice feature is the ability to adjust the pan settings of any channel, whether grouped or not, to adjust the stereo image of a signal without having to compromise the level control. Pan controls are even available on the master stereo output faders.
No mix is complete without the addition of a little help from an effects unit. Good use of reverb, delay and chorus can bring even the dullest of master tapes back to life, and the ProMix offers four individual sends to do just that -- two of them routing to the internal effects section, and two available on the rear of the mixer to connect to external units. These two external sockets can be used as a single stereo feed, or as two individual mono sends, and are numbered 3 and 4 respectively. All the effects sends can be configured to operate in 'pre-fade' or 'post-fade' modes -- 'pre-fade' signals are sent before they get to the master channel fader, and adjusting the volume of the channel does not change the level of the effect send. 'Post-fade' signals are sent after the master fader, so the amount of effect is directly related to the level of the signal within the mix.
The internal effects section contains 30 preset effects, with space for the user to store another 10 edited programs for quick recall. All of the basic effects are available, with some interesting extras thrown in for good measure -- see the effects box for a detailed description.
The ProMix is a great performer, introducing very little apparent noise to the final output signal. Automation with Emagic's Notator Logic is simple and very effective, especially with the advantage of being able to control the entire system from a large screen display and a mouse. Without a computer-based sequencer, automation is still possible by storing entire 'snapshots' of the desk settings as 'scenes', stored internally within the desk. Fifty different scenes can be stored and then replayed, from the front panel, or remotely using MIDI program changes. There is a valid argument that desks such as the ProMix, based around the 'select a channel and tweak' principle can be confusing to operate, and are no substitute for a large console with separate controls available at all times for every possible function. In practice, I found that it was surprisingly easy to adjust to this new way of working, and the benefits of total recall and built-in effects soon outweighed the disadvantages. There is certainly a growing move away from larger consoles, with sales of the outstanding Euphonix console on the increase, and the recent release of Tactile Technology's new desk, both of which are based on the single-channel principle.
The ProMix's internal compression and gates are very effective, as are the effects programs, and the whole unit is remarkably compact (it can be racked if necessary) and 'friendly' to use. I found the EQ very adaptable, and for a digital system, also very musical, with a good sense of depth and clarity. Just about the only potential problem with the console was the fact that the faders had a particularly 'lightweight' feel to them, giving the impression that one of them might just come off in your hand with a sudden movement. I stress that this was certainly not the case with the model that I looked at, but racking a ProMix up and taking it out on the road, with all the associated knocks and bumps may not be the best idea -- this is a well-designed but delicate piece of equipment.
Two manuals are provided with the ProMix -- a quick-start tutorial, and an in-depth book which covers the desk in great detail, both of which are excellent, and a great improvement over some of the Japanese translations often presented to equipment purchasers.
The ProMix represents outstanding value for money. Its sound quality is superb, and the automation and built-in compression and effects make this desk a force to be reckoned with. The absence of digital channel inputs highlights one of the weaknesses of digital desks, and that is that you can't use digital inputs unless either everything is locked to the same master clock, or the mixer inputs include asynchronous sample rate converters. As much of the semi-pro digital gear around doesn't lend itself to master clock sync, asychronous sample rate conversion may be the best compromise for the immediate future. Rumours suggest that Yamaha are currently working on an updated version of the desk (no doubt a lot more expensive) with some form of digital input capability. Multiple desks can be linked together very easily, using the stereo input channel on each desk to slave the outputs together, so multi-channel systems can be assembled with ease, though a dedicated link facility (ideally digital) would have been far more satisfactory. The ProMix isn't a recording desk, but given its price, it might be worth considering recording via your exisiting mixer and using a ProMix purely at mixdown, to gain the benefit of automation and the onboard effects. And because the ProMix has an SP/DIF digital output, the result can be piped straight into your DAT machine.
Regardless of what studio setup you currently use, it's almost certain that adding a ProMix would make it more powerful. If you're looking for a master quality mixing desk, and can manage with 16 inputs, the ProMix may well be the perfect addition to your studio.
There have been many books and articles devoted to the subject of digital audio over the last few years, but it still remains one of the most confusing aspects of the recording industry, and one that causes problems for engineers and musicians alike. If you understand the basic concepts of digital audio, happily skip over this section, but if not, another explanation may be in order.
Sound is effectively a vibration of air. The air moves back and forth very quickly, in sympathy with the sound, as it travels towards the listener. In the same way that ripples on a pond move outwards in circles if a stone is thrown into the water, so sound travels in a similar way. The only difference between the two is that while the surface of the water rises and falls as the ripple moves outwards, a sound 'wave' causes the air to vibrate horizontally as it heads towards your ear. A loudspeaker reproduces sound by moving a large 'diaphragm' back and forth, vibrating the air as well as pushing it out towards the listener. The larger the movements, the louder the sound, and the faster the movements, the higher the frequency of sound that will be produced. When audio is converted into a digital signal, a computer effectively stores the exact position of the speaker diaphragm, thousands of times per second. Every position that the diaphragm assumes is recorded as a number, which is then stored as digital sound. For CD-quality audio, a value of 0 is stored when the diaphragm is at its 'rearmost' position -- when it cannot move any further backwards -- and a value of just over 32,000 is assigned when the diaphragm has moved all the way forwards. Every possible position between the two settings is then allocated a number between these values. As the speaker moves to play an audio signal, its position is stored 44,100 times a second, to produce an accurate representation of the sound, and these numbers can thus be edited and played back at will to produce digital audio.
There are two main variables that govern the quality of the resulting digital signal: the number of values associated with the position of the speaker (a greater spread of numbers will produce a more accurate representation of the position of the speaker -- known as the 'resolution' -- and the better the resolution, the lower the distortion); and the speed at which the readings are taken (the faster the better) -- known as the 'sampling rate', which determines the audio bandwidth. Once you understand the concept of representing a 'snatch' of sound as a number, then the whole digital process is analogous to that of a cine-film, where the more frames per second you have, the smoother the sense of movement.
The ProMix is automated by sending specific MIDI messages from a suitable sequencer or master controller. MIDI In, Out and Thru sockets are provided on the rear of the desk, and once these are connected to the sequencer, the mixer behaves much in the same way as a keyboard or drum machine. Using a basic system, the desk can be 'played', like a MIDI instrument, with every fader movement or control change recorded and then played back at will. A more complex method of working, and one which allows total control over editing any facet of the mix, is to use the console in conjunction with one of the better sequencer packages around, like Steinberg's Cubase, or Emagic's Logic. Both of these systems offer the ability to set up and work with 'Mixer Maps' -- user-defined control panels that can be configured to operate virtually any MIDI device. The ProMix was supplied with a disk containing just such a Mixer Map, already configured for use with Logic, and very good it was too (a similar map is now available for Cubase users). A full-colour representation of the desk appears on screen, with all four auxiliary sends appearing as separate control knobs on each channel (whereas on the ProMix itself, they are accessed via softkeys). The advantage of using a sequencer like Logic is that once a basic mix has been recorded, any part of it can be adjusted, without affecting any other part of the mix. Grabbing a 'virtual' fader on screen with the mouse can overwrite any previous mix information for that fader over that specific part of the mix, and the results are instantly updated on the console itself as the faders automatically slide into action. At present, no EQ is possible from the computer, but perhaps this can be fixed in time for the next release of the Mixer Map. Many thanks to Sound Technology for the loan of Logic for this review.
The effects within the ProMix bear a striking similarity to those found within the SPX90 and SPX900, Yamaha's successful multi-effects units. The basic effects cover reverb, chorus, flange, and pitch shifting as well as auto-panning, and within each program, every parameter can be edited and new versions of the program can be saved for later use. These are some of my personal favourites, but there are a lot more available within the unit:
REVERB HALL 1
Standard Yamaha classic reverb, simulating a large hall, and perfect for those epic ballads. Use heavily on drums and vocals for that 'inside a big church' feeling.
A good vocal plate simulation, with some pre-delay before the reverb fires off, to allow the original signal to cut through whilst still maintaining a real warmth and presence.
FLANGE > REVERB
One of a number of 'multi' effects, this is great for keyboards and pad sounds and mixes a SPX90-type flange with a large reverb, thickening sounds and adding a stereo depth to any mix.
A secret favourite of many top engineers, this is equivalent to 'Patch Change C' on an SPX90, and has been used on countless numbers of records. It's a subtle stereo pitch change, which places a slightly tuned-up version of the signal on the left channel, and a slightly tuned-down version on the right -- perfect for hiding slight tuning discrepancies and smoothing out a slightly suspect vocal performance.
Another Yamaha classic, this is a rich form of chorus, excellent on strings and pad sounds, which produces a very wide sounding, continually moving effect.
Auto panning can be used to great effect to excite a mix, or to create the feeling of movement. It's great on small percussion sounds, or tight, pulsing synth lines, which can be made to bounce from side to side between the speakers. The same effect could be achieved by automating the pan control on one of the input channels, but it is certainly a lot easier to use this on-board processor.
Separate from the effects section, there are three different 'dynamics' processors, each offering compression, limiting, gating and signal ducking. These can be patched across any of the input channels (perfect for vocals and other microphone-based recording), or across the effects sends and the stereo outputs. As always, all of the internal parameters can be edited and stored. Ten different preset programs are available, ranging from a light limiting to a fast, heavy 'radio style' compression, and some other gated effects.
Motorised fader systems are a relatively new concept which, until now (barring Yamaha's other digital releases), have usually been restricted to the megabucks end of the mixing console market. In most automated systems, it can become hard to visually check the status of a mix simply by glancing at the faders on the desk, as all of the levels are controlled by the mix computer, and are likely to differ from the actual position of the faders on the board. Moving faders, however, are motor driven, and automatically move to represent the actual volume, as determined by the automation system. There are two main types of motorised fader -- VCA (Voltage Controlled Amplifier-based), or mechanically controlled. With VCAs, the audio signal passes through a separate electronic volume control, which takes a setting from the fader in order to set the correct level. In this scenario, the actual signal never physically passes through the volume fader, and some signal degradation is likely to occur, depending on the quality and design of the VCA. With mechanical systems, the audio signal does pass through the fader -- as with non-automated consoles -- and this fader is then physically moved, usually by a metal rod attached to it and positioned under the top panel of the mixing desk. This offers a distinct sonic advantage over VCAs, in that the audio signal is routed through less electronics and should remain largely unaltered, although fader calibration and general upkeep of such a system can be more complicated. Yamaha set the standard for cost-effective moving fader systems with the original introduction of the DMP7 digital mixing console some years ago. This was one of the first consoles with a price tag of under £10,000 to offer motorised faders, and was adopted by a number of studios solely for mix automation, often used in combination with another analogue console for track laying. One interesting fact about moving faders is that it is normally possible to flick them really hard from their minimum to maximum level, and store the resulting movement in the automation computer. This can then be played back at will, and is very useful for firing pencils, catapult fashion, over the top of the desk whenever the drummer/tape op happens to be passing!
Frequency Response 20Hz-20kHz, +1/-3dB
THD Less than 0.1%
Dynamic Range 105dB typical
A/D Converter 20-bit linear, 64 times oversampling
D/A Converter Stereo Out: 20-bit linear, 8 times oversampling
Monitor out, aux sends 3&4: 18-bit linear, 8 times oversampling
Processing Internal: 24-bit linear
EQ: 36-bit linear
Sampling Frequency 48kHz
Effect Types Reverb, delay, chorus, symphonic, flanger, pitch change, phasing, tremolo. auto-pan
Compressor Types Compressor, gate, ducking
Faders 60mm motorised
Memories Scenes: 50
Internal Effects: 30 preset, 10 user
Compressor: 10 preset, 10 user
EQ: 30 preset, 20 user
Meters 2 x 12-segment LED bars
Inputs Channels 1-8:: Balanced XLR-type x 8 (+48V switchable phantom power)
Channels 9-16:Balanced quarter-inch phone jack x 8
Stereo In: Quarter-inch phone jack x2
2TR In: RCA/phono jack x 2
Outputs Rec Out: Analogue: RCA phono jacks x2; Digital Coaxial: RCA/phono jack
Stereo Out: Balanced XLR-type x 2
Aux Send: Quarter-inch phone jack x2
Monitor Out: Quarter-inch phone jack x 2
Phones: Quarter-inch stereo phone jack
Weight 12.5kg (27.9lb)
Dimensions (W x H x D) 435 x 125 x 485mm (17 x 5 x 19")
Complete automation, including moving faders.
Integral, high-quality effects.
Highly-specified digital signal path.
No digital inputs.
Mixer is designed really for mixdown rather than recording.
Channel parameter access system is less intuitive than that of conventional mixers.
No proper linking facility for using more than one desk.
For anyone with the slightest imagination and around £2000 to spend, from the project studio owner to the post-production professional, the ProMix must come pretty close to the top of the must-have list.
£ ProMix 01 £1899 inc VAT.
A Yamaha Kamble Music (UK) , Sherbourne Drive, Tilbrook, Milton Keynes MK7 8BL.
T Product Info Line 0908 369269.
F 0908 368872.