Yamaha SPX2000

Photo: Mark Ewing

One of Yamaha's most well-known studio products gets a makeover for the 21st Century.

The introduction of Yamaha's original SPX90 in the late '80s was nothing short of revolutionary for home and professional studios alike. This classic multi-effects processor provided a quality of stereo digital reverb which was quite amazing for both the time and the price, and the array of other time-delay effects — phasing, flanging, chorus, delays, echoes and pitch-shifters — were equally impressive and very usable. This original processor was subsequently upgraded to MkII status before being superseded by the SPX900, SPX1000 and the current SPX990. Not surprisingly, large numbers of all of these units are still in daily use around the world, and there can be very few studios that don't have an SPX unit somewhere in the rack.

The latest product to bear the SPX moniker is Yamaha's new SPX2000, providing the same broad range of facilities as the previous SPX generations. The new machine has a familiar-looking user interface too, along with Yamaha's latest high-quality effects DSP, which powers the new REVX reverb and updated effects algorithms. There are 122 factory presets provided, and the new machine features much improved interconnectivity, as well as 96kHz sample rate operation.

The Hardware

The SPX2000 retains the 1U rackmount case format, although it is a little deeper than most of the other models at 363mm from the rack ears to the rear-panel connectors. The new unit also features a dark-blue brushed-metal finish instead of the all-black control panels of previous models. The front-panel styling and control layout are similar to the very first generations of SPX machines, and the data wheel of the SPX990 has been removed to provide space for a few new buttons — the revision improving the ergonomics and usability, to my way of thinking, as well as accommodating some new features.

A rear-panel USB socket allows the SPX2000 to be connected to a computer for graphical editing via a forthcoming software interface.Photo: Mark EwingIf front-panel control is too restrictive for you, a dedicated software editor is being developed to enable remote control of the SPX2000 from both PC and Apple Macintosh computers connected via a USB port. This editor software was scheduled for release in December 2003, but when December arrived its release was put back to March 2004. When it is finally launched, it will also apparently allow management and archiving of user presets — including allowing groups of presets to be downloaded to the SPX2000 for specific projects or performances, for example. When complete, the editor software will be available for download from the SPX2000 section at www.yamahaproaudio.com.

Digital & Analogue Interfacing

In line with Yamaha's new range of digital consoles, the SPX2000 has been equipped with digital interfacing facilities. AES-EBU digital input and output sockets are provided, along with a word-clock input for synchronisation within a digital studio environment. The only minor disappointment is that an S/PDIF interface isn't included as well — although if necessary it is fairly easy to convert electrical characteristics from one to the other with a suitable 'bodge lead' or in-line transformer.

The analogue interfacing comprises both XLRs and TRS quarter-inch sockets, wired in parallel and accommodating balanced line-level inputs and outputs. Rear-panel slide switches enable the I/Os to be independently configured for +4dBu or -10dBu nominal levels — and it might be worth clarifying (for those who fret about such things) that -10dBu (245mV) is roughly 2.5dB lower than the more usual -10dBV (316mV) reference level. All of which means that this Yamaha device is slightly more sensitive than most when configured to accept semi-professional signals. For the record, the maximum input and output level when operating in the +4dBu mode is a huge +24dBu — enough for any digital recorder. The A-D and D-A converters all support 24-bit word lengths and are 96kHz capable, with 128 times oversampling for the 44.1kHz and 48kHz base sample rates and 64 times oversampling for the 88.2kHz and 96kHz rates. The dynamic range via the analogue interfaces is specified as 106dB.

Photo: Mark Ewing

Aside from the analogue and digital audio interfacing, the other rear-panel connectors are a 'B'-type USB 1.1 port (the square one, rather than the 'A'-type flat one!) for remote control from a computer; a pair of MIDI DIN sockets (In and Out/Thru); an IEC mains inlet; and a grounding terminal. There is no external fuse or voltage selector — European models accept only 230V mains supplies, while a 120V version is marketed in the appropriate parts of the world. Presumably due to a lack of rear-panel space, the CE marking and mains voltage details label is on the top plate of the unit, rather than adjacent to the IEC socket, and may therefore become invisible when the unit is rackmounted, which may be a cause for confusion in some circumstances. The unit's power consumption is 25 Watts.

The Front Panel

Moving to the front panel, the control layout follows the general style of previous SPX units, with a dual-concentric analogue input level knob on the left-hand side, followed by a vertical stereo bar-graph meter, various status indicators, the LCD screen, and the numeric LED preset display. The 12-segment LED meter can be switched to monitor either input or output levels, and a second button selects a mono or stereo input mode. The status indicators show the selected input source, clock source, and sample rate, and whether MIDI messages are being received.

The dual concentric input level control allows you to set each channel's gain separately.Photo: Mark EwingAs mentioned earlier, the unit ships with 122 factory presets in total: 97 in the Preset bank and 25 in the Classic bank. A further 99 presets can be stored in the User bank. The current preset number is shown on the numeric display, while a trio of LEDs shows which bank is currently in use (Preset, User, or Classic) — a small button is provided to select the appropriate preset bank. Many of the effects included in the SPX2000 can also be found in the effects engines of the DM2000, 02R96, DM1000 and 01V96 consoles, and of the 45 factory reverberation effects, 17 use Yamaha's latest REVX algorithm. This is claimed to provide high-density reverberation with natural-sounding early reflections, and more REVX reverb programs will be made available to the consoles with the imminent plug-in effects upgrade options.

The Classic bank of presets is based on the most popular effects of earlier SPX units, and retains relatively limited parameter sets, although they all feature updated algorithms to make them suitable for 96kHz operation. The main Preset bank of effects algorithms generally has a far more elaborate parameter set, but to keep things easy to use the parameters are divided into the most frequently used parameters and lesser-used 'fine' parameters.

Back to the controls, and two groups of four buttons provide the preset store and recall functions, as well as accessing editing parameters. These are followed by a trio of small buttons which access the basic and fine parameter subsets and Utility functions. Finishing off the right-hand side of the panel are a Tap button, a footswitch socket, and the mains power switch. Both Tap button and footswitch can be used to set the tempo of delays or modulations in appropriate effects, although the appropriate tempo mode has to be enabled first. It took me a while to discover this function (which is tucked away in the relevant preset's fine parameter menu), before I could get the Tap button to work!

The central LCD screen provides the usual two lines of 16 characters, but it has the rather funky feature of five different backlight colours. Rather than being a garish gimmick, the different backlight colours are used effectively to indicate groups of related preset families. By default, the reverb programs all enjoy a cyan background; delays and echoes are white; modulation and pitch effects are magenta; filters, dynamics and composite effects are yellow; and the Classic preset bank programs are all green. Should this colour scheme clash with the studio decor, though, then fear not — the backlight allocations can be customised too.Photo: Mark Ewing

Presets & Editing

Finding and selecting a new preset is performed in exactly the same way as on previous SPX units: the bank button is used to select the required preset bank, followed by pressing the neighbouring cursor buttons to scroll through the bank to find the wanted preset. The coloured backlight makes finding a particular type of effect a lot easier, of course. Pressing Recall loads the selected algorithm, while a Save button allows the current preset to be saved in one of the User preset memories. A small Undo button above the main button quartet reverses the previous Recall or Save operation — and this can also be useful for comparing previous and current presets.

The second group of control buttons provides the parameter editing facilities. Back and Next buttons scroll through the available parameters, while the Inc and Dec buttons change the value. Three more slim buttons are used to select the required parameter set: Parameter accesses the most commonly used parameters; Fine Param calls up the lesser-used tweaky elements; and Utility accesses the machine's configuration facilities, such as sample rate and clock source selection, MIDI functions, and so on. A small Compare button allows an edited preset to be compared with its original condition, and a Bypass button does just what it says it does!

The front-panel Input Mode button located beside the metering is used to select the input format. If the SPX2000 is driven from a single aux send, for example, then the input signal can be connected to the left channel and the Mono input mode selected. Although some effects presets require a mono source, others work with a stereo input, but in this Mono mode the left-channel input is used to feed the processor as necessary. If a stereo aux send is available, then the Stereo mode can be selected, and signals can be input to both channels of the processor. The mono-input effects are fed automatically with a sum of left and right input signals, while the stereo effects are fed with the full stereo input as you would expect.

If working with digital input signals, the clock source can be derived from either the AES input signal itself, or the external word-clock input, if available (and synchronous with the AES signal). In practice, though, the word-clock input would probably only be needed when using analogue sources but a synchronised digital output. Incorrect clock selection or timing results in a Sync Error warning display on the LCD panel.

Like previous SPX units, User presets can be protected to prevent their being overwritten, but this new unit also provides three levels of 'operational lockout' to help prevent accidental or inappropriate adjustments to various functions. The first lockout level prohibits access to all of the Utility functions — input and clock sources and all the MIDI functions. Lockout level two adds to that by disabling the User preset store function, and level three goes further by disabling the effect Recall and Editing functions, as well as the Tap and Bypass buttons.

This lockout mode is not password protected, and the facility really only prevents inadvertent operation, rather than malicious fiddling! However, to my way of thinking, level three is too draconian, but level two does not offer quite enough protection! I can think of many instances where you may want the user to be able to recall different pre-programmed presets, but not be allowed to edit them, for example. And in a live sound or theatrical situation it is usually essential to be able to adjust the tempo of repeat effects, which is specifically prevented in lockout level three.

Reverb Algorithms

The first group of effects presented in the Preset bank are 45 reverberation programs, which are essentially based on four different algorithms: called Reverb, Stereo Reverb, REVX, and Early Reflections — all produce stereo outputs, but only the Stereo Reverb and REVX programs accept stereo inputs. Other key differences are that the Reverb and Stereo Reverb algorithms allow the level of early reflections and decay to be adjusted relative to each other; the REVX algorithm allows the reverberation envelope to be adjusted; and the Reverb algorithm has an integral gate function for creating gated reverbs.

There are 17 factory presets which use the REVX algorithm, including a variety of halls (large, medium, small, tiny, warm, bright, and huge), three plates and seven rooms. The basic parameters associated with the REVX presets include initial pre-delay, reverberation time (up to 47 seconds!), high- and low-frequency absorption ratios, diffusion, and room size (which affects the reverb time, as well as the impression of high and low absorption and diffusion). For many, these parameters will enable all the fine-tuning control required, but for inveterate tweakers, there is also a set of fine parameters which include mix balance (wet/dry mix), output level, and high-pass and low-pass output filters. These facilities are all very familiar, but more unusually a Decay parameter (scaled from zero to 53) changes the shape of the reverb envelope and so affects the way the reverb tail decays. A Low Frequency setting determines the centre frequency used for the low-frequency absorption ratio — anywhere from 22Hz to 18kHz!

The Stereo Reverb algorithm is used for four presets: Hall, Vocal Chamber, Thin Plate and Drum Machine Ambience. The basic parameter options include a choice of reverberation type — Hall, Room, Stage and Plate — although, strangely, only the stage and room settings are used in the four factory presets. The other basic parameters are reverb time (up to 99 seconds this time!), high and low absorption ratios, pre-delay, diffusion and density. The fine parameter section includes mix balance and output level, along with the balance of early reflections to reverberation. A setting of zero percent provides just the reverb, while 100 percent provides just the early reflections, and intermediate settings vary the proportions accordingly. Separate high-pass and low-pass filters are also provided.

The Reverb algorithm is equipped with decay time (up to 99 seconds again), high and low damping ratios, pre-delay (up to 500ms), diffusion and density in the basic parameter set. The fine set supplements these with the usual mix balance, output level and early-reflection/reverb balance, as well as another new facility — early-reflection/reverb delay. This offsets the start of the reverberation after the end of the early reflections by up to 100ms, which creates some interesting effects. Other parameters provided here include high-pass and low-pass filters, and a comprehensive set of gate settings: threshold, attack, hold and decay.

The last of the quartet of new algorithms is the Early Reflection program. This is equipped with a Type setting which includes Large Hall, Small Hall, Random, Reverse, Plate, and Spring, plus two gated reverb types. Other basic parameters are room size, liveness, pre-delay, diffusion and density. The fine parameter subset adds mix balance and output level, the number of early reflections (from one to 19), high-pass and low-pass filters, feedback level, and a high-frequency damping ratio for the feedback loop.

Photo: Mark Ewing

Delay & Modulation Effects

The other effects are more traditional time-delay types, such as mono and stereo delays and echoes (with and without modulation facilities), and various modulation effects including flangers, phasers, and so on. Available parameters include frequency, wave shape, depth of modulation, modulation delay, feedback level, two-band equalisation, plus tap-tempo and sync options. The SPX2000 also includes an auto-panner and a ring modulator, both with comprehensive parameter sets, and some intriguing dynamic filters, flangers, and phasers in which either the input signal or an external MIDI command can be used to modulate the effect.

The pitch-change effects were always a weak link in the earlier SPX units, and while the two new offerings provided here alongside the four classic effects are far better than the originals, they are still well short of Eventide standards. Among the fine parameters for the High Quality Pitch and Dual Pitch algorithms is a Mode setting which trades processing delay against precision, and the higher settings are rather less metallic than lower settings. As always, used sparingly and with modest shifts the effects are perfectly usable, but taken to excess they quickly begin to sound very silly!

Again, like earlier units many of the algorithms have been combined to form composite effects such as distortion and flanging, reverb and chorus, delay and early reflections, and so on. Other effects functions include a three-band equaliser, three-band dynamics processing, a rotary speaker effect (with overdrive, rotor/horn speeds and acceleration), distortion (with five distortion types), and an amp simulator (with ten amp models).

Listening Tests

I found the SPX2000 very quick and easy to use, and the division of parameters into basic and fine subsets aided the speed of operation. The display is clear and informative, and the ancillary indicators and meters are all easy to read so that the current operating mode is presented very clearly. The inclusion of the original 'classic' SPX90-style effects makes a lot of sense, since their slightly coarse character is quite distinctive and appropriate to some music genres, as well as often working better in live sound applications.

Having said that, it is the new REVX and associated algorithms that provide the real highlights of this machine. These new reverbs sound remarkably smooth, yet detailed and natural, with believable early reflections which really help to define the smaller room sounds. The ability to generate realistic small room reverbs has become the mark of quality, and something which is usually associated with the better Lexicon and TC Electronic machines — but the SPX2000 can provide remarkably usable small rooms and chambers at a fraction of the UK price of some of these high-end units.

The SPX2000 shares much of its technology and effects programming with the new DM series of digital consoles, and can be integrated very easily into traditional analogue or digital environments, complete with 24-bit/96kHz resolution. It is clear that the SPX processor standard has been raised substantially, with a very polished and versatile range of effects all controlled through a very intuitive user interface. The software editor, when finally released, should enhance this product even further. The SPX2000 will stand up well in auditions alongside multi-effects processors costing twice this UK price!