The EZbus from Event Electronics is an impressive hybrid that combines a digital mixer, a virtual control surface, and an audio/MIDI interface into a single package costing about what you would pay for a unit dedicated to any one of those functions. The EZbus's mixer impressed me the most — it offers lots of inputs and outputs in a compact footprint, its signal routing is versatile, and its layout is easy to learn and navigate.
As a control surface, the Event Electronics EZbus comes off pretty well, too, with multiple layers of control assignments and a straightforward programming applet included. Getting its audio interface functions running properly was a bit more of an adventure than I expected, but the folks at Event were helpful in getting it all sorted out. Here's a closer look at each of these functions.
ALL MIXED UP
The Event Electronics EZbus is one of the most economical digital mixers on the market. All of its analog inputs and outputs feature 24-bit, 96 kHz converters, and the S/PDIF will pass the same resolution. Its Lightpipe connections don't do sample splitting, though, so they go up to only 48 kHz sampling rates (though still with 24-bit resolution).
The EZbus's first two analog channels can be accessed through either balanced XLR or ¼-inch TRS jacks (see Fig. 1). The XLR connectors provide mic preamps with switchable 48V phantom power; the ¼-inch jacks allow for mic- or line-level sources. The next two analog inputs feature ¼-inch TS connections at instrument or line level. Those two inputs are designed for use with instrument-level signals, though they can also accept line-level signals. Four more line-level inputs are available, each of which features three ¼-inch TRS connections summed together. For anyone with several synth modules, it's a cost-effective way to get a lot of signals into the mixer without repatching all the time.
This adds up to a total of 16 mono analog inputs available at one time — not a bad channel count if you can deal with the interdependence of those summed inputs. Inputs 1 through 4 are completely independent in terms of pan, level, and internal effects; inputs 5 through 8, however, require a bit of planning. For example, if you're using the summed inputs for L/R outputs of synth modules, you could simply plug the first module in to inputs 5A and 6A, the second in to inputs 5B and 6B, and the third in to inputs 5C and 6C, and then you could pan inputs 5 and 6 hard left and right. Before you get bummed about having three synths sharing the same soundstage, keep in mind that you can use MIDI pan and volume controllers to separate and balance individual timbres and each synth module's master volume to balance the levels of the three devices.
Three pairs of analog outputs are available on ¼-inch TRS jacks, and there is also a ¼-inch stereo headphone output with a dedicated volume control. The Main output pair carries whatever is assigned to the Main Mix, and the Sends 1 and 2 output pair carries whatever is assigned to Sends 1 and 2. The Aux output pair, however, can be assigned to carry the Main Mix, the Alt Mix, Sends 3 and 4, or a direct output of any analog or digital input. The headphone channel offers the same possibilities and the ability to carry Sends 1 and 2. Although the EZbus has no surround features per se, it would be easy enough to create a mix preset that utilized these outputs for a 5.1 monitoring setup.
Digital connections on the EZbus consist of ADAT Optical (Lightpipe) and S/PDIF coaxial I/O (see Fig. 2). A second, independent coaxial S/PDIF output is also available, and the Lightpipe input can detect and automatically switch to accommodate optical S/PDIF. All digital connections support 24-bit audio, and the coaxial ports support sampling rates up to 96 kHz. The coaxial S/PDIF input has a built-in sampling-rate converter, so you could be working on a 44.1 kHz project and bring the signal from a 48 kHz device into the EZbus; that signal would be downsampled on the fly to 44.1 kHz. The EZbus's optical ports, however, max out at 48 kHz. In terms of mixer architecture, the USB port can be considered another stereo digital I/O pair (48 kHz maximum). Though labeled L & R, the USB channels are actually two mono channels and can be treated as such.
A quick run through the EZbus's signal path will give you an idea of the unit's flexibility. Any digital or analog input can be assigned to the Main Mix, the Alt Mix, or both through one of Primary Audio Channels. Each of those eight channels provides digital trim and phase controls, equalization, dynamics, four sends (independently assignable pre- or postfader), pan, level, mute, and solo. The Main Mix can also carry as many as four additional inputs through Returns 1 through 4. Returns 1 and 2 provide level and pan controls, and Returns 3 and 4 act as a stereo pair, providing only level controls.
At a glance, you can see that the EZbus doesn't allow you to mix all of its inputs simultaneously. Nevertheless, using the inputs in the most efficient way, you could have 2 mic signals, 2 guitar signals, 12 (4 by 3) synth signals, and 4 channels of digital input, all running to the Main Mix simultaneously, for a healthy total of 20 inputs. Four of those inputs (the Sends) would not have EQ and compression, and the summed inputs (5 through 8) would be processed together.
It's worth noting that the Alt Mix isn't actually an independent mix but merely an alternate set of Primary Audio Channels. A Channel belongs to either or both of the Main and Alt Mixes, but it carries only one level and one pan value, regardless of where it's assigned. The Alt and Main mixes do, however, have independent level controls, making the Alt mix useful for the control-room monitor signal.
Although the Main Outs and Sends 1 and 2 are hardwired to carry the Main Mix and Sends 1 and 2, respectively, the other digital and analog outputs can carry a variety of different sources. With some exceptions, you can route the Main Mix, the Alt Mix, the Sends, the output of any Primary Audio Channels, or the unprocessed signal from any analog or digital input to any remaining digital or analog output. The EZbus is essentially designed to allow routing of any input to any output. You could, for example, go directly from line input 3 to the Universal Serial Bus (USB), bypassing virtually everything in between. Also, when you go from a digital input directly to a digital output — say, from an ADAT input to a S/PDIF output — a direct bit-for-bit copy is produced.
The 3-band EQ available on each Primary Audio Channel features high and low shelving and a fully parametric midband. Each band offers 12 dB of gain, and the midband's center frequency ranges from 62 Hz to 10 kHz. Per-channel dynamics processing includes a gate and a compressor. The compressor also has a look-ahead function, which, in combination with the “infinite” ratio setting, allows it to be used as a limiter, as well.
All mix parameters can be saved to one of 32 snapshots. Snapshots can be recalled either from the front panel or by a footswitch. It would be great if you could recall snapshots through MIDI Program Change messages, but that is not possible. However, a handy Mix Librarian applet is included, allowing you to edit, back up, and load banks of snapshots. In a live scenario, you could have a different mix for each song, arrange them in set order, and load in other snapshots on a break, if needed. The load time is under one second, so you could easily load between songs.
At the touch of a button, the EZbus converts from a digital mixer to a control surface for your favorite software. Several device profiles are available: Steinberg Cubase, Nuendo, Model-E, and LM4; Cakewalk Sonar; Emagic Logic Audio; Native Instruments B4; IK Multimedia SampleTank; Propellerhead Reason and ReBirth; a CS-10 emulation for Pro Tools; and even a generic MIDI mixer. Profiles for Syntrillium Cool Edit Pro, MOTU Digital Performer, and BIAS Deck should be available by the time you read this. In addition, the included Profile Editor applet (see Fig. 3) allows you to adapt the mappings to whatever program you wish to control, and Event recently posted a Profile Downloader applet for the Macintosh.
Under Windows ME and XP, the EZbus is able to send MIDI and audio data to the computer simultaneously through the USB port — its control messages require no additional connection. However, under Windows 98SE or 2000 or under Mac OS 9.0.4 through OS X 10.1, the EZbus supports audio through USB only. Therefore, if you are using a separate MIDI interface, the EZbus is able to send its control messages through either of its MIDI ports to communicate with those operating systems. Mac OS X 10.2 will support audio and MIDI simultaneously through USB, so no additional MIDI interface will be required.
On my XP and ME machines, I was able to get control of my software easily. The included profiles for Cakewalk Sonar and Steinberg Cubase VST/32 were laid out in a sensible fashion, and they worked as advertised. Each Profile implements bank select in a different way. For example, the Next and Previous buttons get used in Sonar, whereas the VST profile allows you to switch banks by using Shift + C and pressing a Channel Select button. That way you can jump from, say, bank 1-8 to bank 57-64 without having to page-up or -down through all the banks in between.
The eight buttons dedicated to Inputs, Outputs, EQ, and so forth (when the EZbus is in Audio mode) become V-buttons in Virtual mode. Each V-button has as many as four pages of control assignments, for a total of 32 pages of virtual controls. Within each page, you can assign MIDI notes, controllers, RPNs, or NRPNs to each of the nine faders and channel-select buttons. The Mute and Solo buttons act as modifier (Shift) keys, adding three additional functions to each select button. The data wheel can send a different message with each select button, as well.
The transport buttons can function as indicated, or they can be assigned to other functions — for example, triggering drum sounds and loops. The transport buttons do double duty by default, setting and recalling Locate points in conjunction with the channel-select buttons. A standard momentary footswitch (not included) can be used to advance through Mix settings or as another source of virtual control.
The Profile Editor applet strikes a good balance between power and ease of use, but it could use better documentation. It took trial and error (though not a lot of genius) to determine that I needed to double-click on the line describing a particular page to open the editing window for that page — there is no dedicated button or menu item. Furthermore, it took me a bit of reverse engineering to figure out that, within a page's Edit window, if an item such as Channel Fader (1-8) is assigned to controller 12 on channel 16, then channel faders 1 through 8 send controllers 12 through 19, all on channel 16. Functions for each page of controls are described on the EZbus's LCD, which provides two 20-character lines. Loading a new profile into the EZbus is a one-click operation, and it takes only a couple of seconds for the entire profile to load.
My favorite aspect of the EZbus's control-surface functioning is the way the faders behave when their physical position doesn't coincide with the value of their function. On a control surface with motorized faders, each time you move from one bank of tracks to the next, the faders update with the values of the new tracks. On a nonmotorized device such as the EZbus, moving from bank to bank presents a potential problem. On some control surfaces, if the fader is at unity but its corresponding track's onscreen fader is at a different value, as soon as you move the physical fader, the onscreen fader jumps to unity and moves with the physical fader from there. That makes it virtually impossible to make subtle adjustments without stopping to match the faders to the onscreen values — a process called nulling.
The EZbus solution is to null the faders on the fly. When the physical and virtual controls don't match up, the physical control will not affect its virtual counterpart until it reaches the onscreen value. In the previous example, then, you would have to move the fader from unity to the onscreen fader's position before it would “catch” the onscreen fader and begin adjusting its value. Alternatively, if you hold down the channel-select button and move a fader, you can make immediate relative changes in the value of the onscreen fader. There's also a fader page in the Mix menu that shows whether a fader is clean (that is, the physical position matches the fader value) or dirty (the fader and value and do not match), as well as a bar graph showing the relative values of all the faders. All makers of nonmotorized control surfaces should adopt those implementations.
Although much of the negative talk about using the USB for digital audio is overstated (if not downright unfounded), there is still often a bit of voodoo involved in getting it to work correctly. Lack of conformity to the standard in controller hardware and operating systems has made the job of USB audio developers rather similar to the task of clearing minefields. (According to Event, the EZbus adheres strictly to the USB Audio Device Class and USB MIDI Device Class specifications.) I've tested most of the USB audio interfaces on the market, and each of them has ended up working properly — but only after I jumped through a hoop or two.
My EZbus experience was no different. I installed the EZbus first on my Celeron 1 GHz notebook and tried recording into Sonar and Cubase. I had mixed results in Cubase. When recording an audio track into Sonar, however, my computer crashed repeatedly. Actually, it was more like a spontaneous shutdown. (I wish that the computer would shut down that quickly when I turn it off!)
A call to the friendly folks at Event tech support yielded Safety Tip No. 1: 24-bit operation requires Sonar 2.0. Fortunately, 2.0 was already sitting on a shelf waiting for me to find time to install it. After further discussion with Event, we also discovered that my notebook uses a USB Open Host Controller (OHC) instead of a Universal Host Controller (UHC). Turns out that that's a bad thing, which leads me to Safety Tip No. 2: if you're planning a system with an EZbus, first do some homework to determine what your machine uses. On a desktop computer, you could add a PCI-to-USB card to resolve the problem; on a laptop, try a PC Card — to — USB adapter. (Note that, according to Event, the OHC problem is not specific to EZbus — it's a problem with all USB audio devices. OHCs are used on budget laptops because the chip set is inexpensive. The unfortunate trade-off is that OHC chip sets are more prone to problems than UHCs.)
My solution, which yielded a huge improvement, was to start from scratch on my desktop machine. My desktop computer uses an Intel Universal Host Controller, and the installation went beautifully. Event offers an online help file called 24-Bit Sonar Fix that instructs you to change one setting in Sonar's aud.ini file in order to get 24-bit operation running smoothly. The WDM drivers allowed me to achieve a latency of around 13 ms on a Pentium III/450 MHz. That is acceptable for playing soft synths, one of Event's stated intentions for the EZbus. However, when recording audio tracks, 13 ms is uncomfortable for software monitoring, so I chose to monitor the audio inputs directly from the EZbus. Monitoring that way, you get essentially zero latency.
For some strange reason, Cubase wouldn't recognize the EZbus ASIO drivers at first. Fortunately, another call to tech support led to a quick resolution. It required entering a simple command from the DOS prompt — interesting if only for the nostalgia factor — which forced the computer to take notice of the ASIO driver. (Another way to do the same thing is to drag the asioezbus.dll file over the Regsvr32 icon, avoiding DOS entirely. That ASIO registration procedure can be found on Event's Web site with the latest ASIO driver.) Once I restarted the computer, I was able to select the EZbus ASIO driver in Cubase (see Fig. 4) and get the kind of performance I expected. The latency was around 18 ms, which is borderline for playing virtual instruments. For most applications, I was able to adjust to the delay; for a serious keyboardist playing technically demanding parts, however, it could be a problem.
Mac OS 9.x users will be disappointed to learn that there are no ASIO or MOTU Audio System drivers available, leaving only 16-bit Sound Manager support. For someone who is using an EZbus and a PowerBook to play live, that factor isn't a big issue. But it definitely limits the unit's appeal, at least as an audio interface, for Mac-based personal studios. Of course, OS X allows 24-bit operation (and reportedly with very low core-audio latency), and as more applications are updated to support the new operating system, the OS 9.x limitations will become less of an issue.
It's hard to argue with a product that offers as much as the EZbus. Used in a live rig, the EZbus provides boatloads of I/O with built-in EQ and dynamics and 32 mix snapshots. If a computer is part of your setup, you can add multiple banks of snapshots, transport controls for your sequencer, and the ability to play virtual instruments to the unit's bag of tricks. You can also combine virtual synths with your hardware synths.
In a project studio, the EZbus makes a great hub for linking your instruments, mics, tape decks, and other devices to your monitor system and to your computer for recording and playback. With the addition of Event's EZ8 PCI card ($199) or a similar Lightpipe interface, you can record and play back eight audio tracks at a time using the EZbus's Lightpipe I/O. Its compact size makes it ideal for the typical space-starved studio, and its uncolored mic preamps and converters leave you the flexibility to process and color the sound as you see fit.
If one or more of the EZbus's personalities fits your needs — and your OS and USB controller match up with its requirements — you'll definitely want to check this unit out. The EZbus not only delivers what it promises, but it does so with an exceptionally big bang for the buck.
Brian Smithersis course director of Audio Workstations at Full Sail Real World Education in Winter Park, Florida.
FEATURES4.5EASE OF USE4.0AUDIO QUALITY4.0VALUE4.5RATING PRODUCTS FROM 1 TO 5
PROS: Flexible mixer architecture. Plentiful analog and digital I/O. A/D/A conversion is 24-bit, 96 kHz. Cost-effective, multipurpose design. Thirty-two mix snapshots. Thirty-two “pages” of MIDI control per profile. Useful ancillary applets.
CONS: Needs better documentation of control profiles. Needs profiles for more programs. Fully supported only in Windows ME/XP. Mac OS X 10.x required for 24-bit audio. Requires USB Universal Host Controller.
Analog Inputs(2) balanced XLR mic; (2) balanced ¼" TRS mic/line; (2) unbalanced ¼" TS instrument/line; (12) balanced ¼" TRS (4 sets of 3 summed)Analog Outputs(2) balanced ¼" TRS (main); (2) balanced ¼" TRS (aux); (2) balanced ¼" TRS (send); (1) ¼" stereo (headphone)Digital I/O(1) USB port; (1) S/PDIF coaxial input (RCA jack); (2) S/PDIF coaxial outputs (RCA jacks); (1 pr.) ADAT Lightpipe (Toslink)Other Ports(2) MIDI In, Out; (1) ¼" footswitch; (1) BNC word-clock outputA/D/A Converters24-bit, 96 kHzDigital Signal Processing24-bitSampling Rates32-96 kHz, selectable (analog, S/PDIF, AES/EBU); 44.1, 48.0 kHz (ADAT Lightpipe)Analog Aux Sends/Returns4/4Channel EQ3-band (on each primary audio channel): low shelving; high shelving; parametric midbandFaders(9) 60 mmAutomation32 internal snapshots of all mix parametersDynamics Processorscompressor/limiter/gate (on each primary audio channel)Display2 × 20-character LCDLocate Points8Frequency Response20 Hz-20 kHz (±0.5dB)Signal-to-Noise Ratio>101 dBTotal Harmonic Distortion + Noise<0.003%Crosstalk<110 dBPowerinternalDimensions16.75" (W) × 2.25" (H) × 9.50" (D)Weight12 lb.