Behringer DDX3216

Can a digital console at such a low price really deliver on features and audio quality?

Despite the proliferation of computer-based studios, few of them can manage without a mixer, and in these days of recallable, resetable everything, digital mixers tend to be more attractive than their analogue counterparts. Behringer's offering in this department provides a surprisingly comprehensive feature set at a startlingly low price.

The mixer can handle up to 32 channels, it has 16 internal busses and eight aux sends as well as dynamics and gates plus four-band parametric EQ on every channel (but not the busses). It also includes four onboard effects processors based on the Behringer Virtualizer algorithms. The console also has moving-fader automation via full-length 100mm Alps faders, snapshot automation and I/O expansion via two card slots. Up to 128 snapshots can be saved, a snapshot comprising virtually all the console parameters other than the analogue gain settings. 24-bit Crystal converters (delta-sigma, 128x oversampling) are used throughout and the majority of the circuitry is surfacemount. Sample rates of 44.1kHz and 48kHz are supported while the operating firmware for the mixer is held in flash ROM so that it can be updated from a PC if necessary.

As with all assignable digital mixers, the I/O that you see on the outside is somewhat different from the internal bussing structure, so while the console may indeed have 16 internal busses, it only has two main analogue outs, plus four more assignable outputs, unless you add some more I/O via the card slots. In this respect, the output arrangement is very like that of the smaller Yamaha mixers and recorders. The I/O expansion options are for 16-channel ADAT and TDIF, as well as eight-channel AES-EBU, with all but ADAT being connected via D-Sub multi-pin connectors. An external XLR connector box accompanies the AES-EBU interface, though no expansion cards were supplied with the review sample. There's no analogue expansion option, so it's my guess that the mixer is aimed primarily at the current crop of hardware recorders (ADAT tape or most current hard disk models) that can be fitted with digital I/O, or at computer systems with ADAT I/O.

There's also coaxial S/PDIF I/O where the input is automatically sample rate converted to avoid clocking problems. Routing is fixed to channels 13/14 so, when switched on, it replaces any existing sources. The digital out always follows the main stereo mix and may be 16, 20 or 24-bit with or without noise-shaped dither. Rear-panel word-clock input and output BNC connectors make integration with a more complex digital system possible and there's also a balanced SMPTE input on an XLR. MIDI In, Out and Thru connectors are fitted along with an RS232 port for connection to a PC for data exchange and backup. Mix data may also be stored to an optional PCMCIA card via a slot in the front edge of the mixer and, using a suitable card reader, data may also be transferred to and from a PC that way.

The 32 channels are serviced by 12 mic/line inputs and four line-only inputs making it possible to input up to 16 sources without requiring an expansion card. Phantom power is switchable in two banks covering channels one to eight and nine to 12. Each of the (balanced) mic/line channels includes an insert point prior to digital conversion as well as a 20dB Pad switch with Signal and Clip LEDs to monitor input stage activity. A small gain trim pot completes the input stage, after which the signal is digitised and routed to the floating-point DSP mixing engine. The choice of floating-point processing (powered by four SHARC DSP chips) is interesting because it means the mixer can be designed with a huge internal dynamic range. In a properly designed floating-point system, provided that the input and output levels are OK, there should be no possibility of internal clipping, even at radical EQ settings.

Before leaving the top section of the mixer, where the majority of the sockets and input controls are located, I should also mention the Phones out, with separate level control, and the control-room level control (with 'Mon -20dB' button above the master fader) plus two-track playback switching. Monitor source switching is possible via the LCD and includes mono/stereo switching.

Connection for a stereo recorder is via unbalanced RCA phono connectors on the top panel, where there's also a button for routing the two-track output to mixer inputs 15 and 16 for those occasions when you want to use a recorded source as part of a mix.

Surfing The Operating System

The operational paradigm of the mixer is sufficiently similar to that established by Yamaha that existing Yamaha O-series owners should have little problem finding their way around the DDX3216. The most obvious initial differences are that some aspects of the routing are arranged differently and there's no EQ or dynamics on the 16 Groups, but in other areas there are operational improvements over most competing lower-cost digital mixers, such as the rotary encoders in each channel strip with 'ring of LEDs' read-out, separate compressors and gates that can be used simultaneously, full-length faders and the sheer number of possible inputs and busses. There are also four effect processors rather than the usual two.

One operational nicety that impressed me very early on was the use of the context-sensitive prompts that appeared whenever I tried to do something that might not be entirely obvious — such as when copying settings from one channel to another. In fact most aspects of the console are refreshingly clear, including the unusually concise manual.

The front-panel layout is encouragingly straightforward with all the function access buttons set out in clearly-defined sections to the left of the display: Fader, Channel Control, Proc(essor), General and Auto(mation). Below the display are six rotary encoders with integral push switches that usually act as 'enter' buttons and these relate to on-screen parameters such as EQ or processor settings, routing, setup and so on, with a further four context-sensitive buttons to the right of the screen. As with most assignable consoles, variable levels relating to channels, busses, aux sends and so on are handled using the channel faders and rotary controls, while EQ and processing is controlled via the display and the physical controls associated with it. Snapshot management is handled in a small section to the right of the screen, enabling snapshots to be saved, recalled or stored with a simple but highly visible numeric display showing the currently selected snapshot number. Snapshots can be called up manually or they may be included as part of a dynamically automated mix, in which case parameter fade times can be entered to avoid abrupt transitions. A 16-step, stereo bar-graph meter monitors the main output.

Again common to most digital mixers with assignable controls is the somewhat sparse appearance of the channel strip when compared with that of a typical analogue mixer. The only variable controls are the fader and the rotary encoder with buttons for Select, Auto/Rec, Solo and Mute (which can be set pre- or post-fader depending on whether or not you want to kill the aux buss feeds as well). The console has the ability to program mute groups, enabling a predetermined set of channels to be muted and unmuted using a single button. It's also possible to create fader groups, enabling a number of channel levels to be controlled via a single fader.

The rotary encoders can access any of the eight aux sends or the channel pan, the function being switchable from the Channel Control section using dedicated buttons. Whenever the function is changed, the LEDs surrounding the controls change to depict the value of the currently selected function. Channel levels are shown by 16-element meters alongside each fader and these can be set in the Meters menu either to follow the fader designation or to show the values on one fader bank while adjusting another. The meters read pre- or post-fade as is appropriate for the selected fader bank function. Selecting a channel for editing or adjustment is accomplished in the usual way via the Select button and channels may also be paired for stereo use from one of the General menus.

Stereo master levels are controlled via a single fader above which is the monitor dim switch and the Solo Enable button. The rotary control above the fader normally functions as a stereo balance control but may also be set to operate as a master aux or effects send level. Solo works conventionally, feeding the control room outs when active, but is rendered inactive when the Solo Enable switch is set to off. Solo Enable can also be switched off to cancel all current Solo settings.

Because the mixer has more channels than faders, the fader operation is organised into banks with the first bank relating directly to the 16 physical inputs and the second bank addressing the optional I/O cards. The third bank relates to the 16 buss levels with a fourth bank taking care of the aux sends and effects returns. Channels may be routed directly to the stereo mix buss or to any of 16 group busses, which are arranged as eight stereo busses for routing purposes. When feeding the busses, the channel signal can be set pre- or post-fader, which is useful when working with an external multitrack machine, as it allows the monitor level to be adjusted without changing the 'to tape' levels. The buss outs (which have no EQ, dynamics or aux sends) normally feed the expansion I/O slots, though they can also be assigned to any of the four Multi outputs, as can any of the aux busses, the stereo solo buss or the main stereo output. Buss outs may also be routed back to channel inputs if necessary, but care must be taken not to set up feedback loops by routing something to itself. The reason this feature is included is that it enables the I/O routing to made more flexible by using the busses as routable conduits. The default routing for the expansion cards can also be changed, but only on blocks of eight channels.

DDX3216 rear panel showing the blanking plates for optional I/O cards.As with most of its competitors, the DDX3216 makes use of libraries to store settings for its internal effects and processors (EQ as well as dynamic) plus the complete settings for individual channel strips. An A/B compare function makes it easy to check one setting against another.

The EQ section is fully parametric, with all parameters displayed on screen and controlled by the knobs beneath them. Up to 18dB of cut or boost is provided in each band. The leftmost rotary control moves the cursor between bands and a separate high-pass with a 12dB/octave slope (tunable from 4Hz to 400Hz) can be called up on a separate page.

I was impressed to find that every channel's in-built compressor can have its side-chain controlled from any other channel as well as from its own input, which enables the user to set up ducking effects quite easily. In other respects, the compressor is similar in concept to the one found in Yamaha mixers, with variable threshold, ratio, attack, release, knee and gain. A small area to the right of the display page shows the compressor curve and gain reduction. The gate may also be side-chain triggered and comes with variable attack, threshold, release, range and hold parameters plus a curve/gain-reduction display similar to that of the compressor.

It isn't unusual for digital mixers to feature variable channel delay, but here the delay has enough range and parameters to be used as an effect as well as a timing corrector. The delay time, which may be set to multiples of tempo as well as time, can be set to a maximum of 276 milliseconds with variable mix and feedback. Delay is available only on the first 16 channels, though all 32 channels have switchable phase.

Automation Facilities

The DDX3216 has all the automation features you'd expect from a mixer of its type, including the ability to store libraries of channel settings, EQ, dynamics processing and effects. It can also save and load up to 128 static snapshots. Dynamic automation may be run against SMPTE, MTC (at all standard rates including drop frame) or the mixer's own internal clock, and virtually any parameter change other than the analogue input gain can be recorded for later playback. A dynamic automation mix stores a snapshot that defines the starting conditions of the mix and then follows this up by recording any subsequent dynamic changes. A start snapshot of the current desk setup is created automatically when you clear the previously stored mix.

Automated controls are 'controller sensitive' insomuch as the mixer can tell when a control has been moved and, if that channel is in record-ready mode, new changes will be recorded from the time the console detects a change has been made. Unmoved controls remain in play mode so you don't have to keep disabling automation recording functions, such as dynamics or effects, to keep them safe from unplanned changes when you're working. The automation modes are Record, Play and Relative, the latter being a trim/update mode to add or subtract values from existing automation data. In Relative mode, the faders move to their 0dB position, which means you can increase levels by up to 12dB or reduce them by as much as you like.

There are also global Record and Play switches that affect all channels when dynamic automation is switched on. When the automation is off, these same buttons operate a 'snapshot safe' function, which simply means any selected channels won't be affected when a new snapshot is loaded. If a snapshot is recalled during the recording of an automated mix, any channels set to Play mode will ignore the snapshot while any set to record-ready mode will change to reflect the snapshot data and the changes will be stored accordingly. This system doesn't relate back to the original snapshot data, but rather copies it in real time while recording mix automation, so if the snapshot is subsequently changed or deleted, it won't affect the recorded automated mix.

Each channel has its own Auto/Rec button with tricolour status LED indicating the automation mode. When the global Write switch is pressed, all channels go to record-ready status, so if you need to make any safe or place them immediately into write, you must do so manually before proceeding.

To prevent abrupt transitions when editing mix data, there are three 'release' options available when dropping out of mix record. The Fadeback option allows for a smooth transition at a rate set by the user, whereas Offset adds any remaining offset to the data following the point at which the mix edit ends. In other words, if you come out of automation record at a level 2dB higher than the data you are overwriting, 2dB will be added to all subsequent data. Finally, you can opt to Write To End so that your final automation level is held until the end of the song. Unacceptable passes may be undone using a conventional undo feature.

Note that the console stores just one automation file, which must be purged from the internal flash memory before you can do another (after backing up to PC or PCMCIA card if you need to go back to it). However, you can run a single mix to cover, for example, a whole reel of tape, and simply call up a fresh snapshot to define the start of each song on that tape.

The DDX3216 In The Studio

Because of the intuitive operating system, I was able to find my way around this console pretty quickly and, where help was needed, it was either forthcoming from the context-sensitive display prompts or easily found in the manual. Clearly a console this affordable must be built to a price, but from the outside it's not obvious where corners have been cut and there is even a free extended warranty available for users who register their purchase. The PC software is not included, as it is subject to frequent revisions, but the latest version may be downloaded at www.behringer.com. Unfortunately, it is available for PC only, so I was unable to test it.

Starting with the mic amps, though they are not as sensitive or as clean as good outboard mic amps, these are adequate for most jobs and are comparable to those fitted to the budget Yamaha desks. Most of the gain is right at the top of the trim control, and when two channels are set to maximum gain, there's some audible crosstalk between the channels, but it's not something that should present a problem in most real-life situations. Even so, I'd prefer to use a good external voice channel connected to the line input for anything not being close-miked.

Digital desk EQ varies enormously according to design. For example, my Yamaha O3D works like a textbook description of an EQ in that it makes selected parts of the audio spectrum louder or quieter, but it doesn't actually change the timbre of the sound very much. Cutting the high end on an aggressive violin, for example, results in the aggressive element of the sound being pushed down in level, but it doesn't sound as smooth or as rounded as when doing the same thing with an analogue EQ. My impression of the Behringer EQ is that it falls somewhere in between these two extremes, and it's certainly very usable in most situations. It's also very easy to adjust, with one knob for moving between bands and others for directly adjusting the selected band's parameters.

It was a similar tale with the compressor, which I felt sat somewhere between analogue and digital and had a slight tendency to pump, so if you want something to sound as though it is being compressed, you just need to push it hard. Having the option of side-chain control is useful, as is the facility to assign both a compressor and a gate to any channel.

Routing is easy to set up, though I would have liked to have been able to select the digital input as a two-track return for patching in my DAT recorder. As to the effects, while I've never placed the Behringer Virtualizer near the top of the pile of hardware processors, it's certainly competent and quite versatile for the price, providing all the bread-and-butter effects you're likely to need in a mix. Having access to four internal Virtualizers means you're unlikely to need external effects, though you can patch in others easily if you need to.

In terms of automation, although there's no fancy off-line mix editing, it's actually easier and quicker just to record the relevant mix moves again in most cases. The Automation menu pages allow you to choose which parameters are to be recorded (fader, pan, EQ, phase/delay, compressor, gate, routing, aux sends, effects sends and effects parameters) so patching up a mix or adding dynamic effect changes is pretty straightforward. I like the long-throw faders and the dedicated hardware buttons for accessing the main automation modes, and, of all the mixer automation systems I've tried, this is perhaps one of the easiest to use.

More Bang For Your Buck

The DDX3216 certainly gives you a lot of mixer for your money. It combines a no-frills approach to digital mixing with a generous allocation of channels, effects and dynamics processing, while omitting those things most people are unlikely to need anyway, such as EQ and dynamics in the busses, off-line automation editing, surround panning and suchlike. The routing system offers sufficient flexibility without going overboard, and the internal structure means that it won't feel underpowered if you fill up both expansion slots.

The overall sound quality compares favourably with other low-cost digital consoles, with the EQ section offering a good analogue/digital compromise. I was also favourably impressed by the smooth fader action when running automated mixes. While the mic amps aren't the best I've heard, they're adequate for most applications and comparable with the competition.

Perhaps the lack of analogue I/O expansion may discourage some potential purchasers, but for anyone wishing to interface with a digital system using ADAT, TDIF or AES-EBU, the available expansion options are fine, and of course using the expansion sockets for recorder I/O frees up the 16 analogue ins for tracking or for feeding MIDI instruments back into the mix. No digital console will satisfy everyone, but I have to admit that the DDX3216 gives you far more than you might expect for the price, with surprisingly few compromises.