Although digital audio workstations and standalone digital mixers both offer advantages, there are several good reasons to use a standalone digital mixer instead of mixing entirely with a mouse in a DAW program. By offering the obvious benefits of real faders and knobs, easy monitoring with negligible latency, and hardware control of DAWs, modern digital mixers grant the kind of tactile mixing that mouse jockeys only dream of. Most digital mixers also furnish EQ and compression on every channel without taxing your CPU or increasing latency and memory consumption as plug-ins do.
Such advantages are well illustrated by Tascam's latest offering, the DM-24, which is positively stuffed with goodies that modern studios need. Tascam was not the first or even the second company to plunge into the small-format digital-mixer market, but its entries have steadily gained popularity.
The DM-24 features a potential 36 analog and 24 digital inputs, TDIF and ADAT Lightpipe I/O, 96 kHz operation, surround mixing, onboard effects by TC Works and Antares, extensive machine-control capabilities, and sophisticated automation using touch-sensitive motorized faders. Perhaps the greatest demonstration of how far digital mixers have come is the DM-24's price of less than three grand.
FORM FOLLOWS FUNCTION
Considering its depth of functionality, the DM-24 has a small footprint, measuring only about 23 inches wide and 26 inches deep (see Fig. 1). The analog inputs and outputs are located at the top of the front panel. I usually dislike connections there, but with all of the digital and control inputs on the DM-24's rear panel, there wasn't space to fit the analog connections back there too. If you don't have patch bays, you might appreciate the ease of repatching that front-panel connections offer.
The DM-24 features 16 channels of analog input with an XLR mic input, a balanced TRS line input, and a TRS insert point on each channel. Mic/line switches are conspicuous in their absence, and Tascam cautions users against connecting to mic and line inputs on the same channel. That arrangement is unfortunate, as it will force considerably more repatching for tracking and mixing sessions and precludes bringing all of the analog connections to patch.
Four assignable sends and four assignable returns can be configured either as channel inserts or as aux sends and returns. With the software that I used (version 1.6), if they aren't configured as inserts, sends are routed from any of the six internal aux buses, and the returns are routed to channel inputs. (See the sidebar “DM-24: The Next Generation” for a discussion of forthcoming revisions.)
The main mixer outputs are carried on balanced XLR jacks accompanied by ¼-inch TRS insert jacks. Control-room monitoring is on ¼-inch TRS jacks, and studio monitor outputs are on RCA jacks. Two stereo headphone jacks round out the DM-24's complement of analog I/O.
The rear panel's digital and control connections include 24 channels of TDIF and 8 channels of Lightpipe, as well as 2 switchable input and output stages that accept either AES/EBU from XLR connectors or S/PDIF from RCA jacks (see Fig. 2). Real-time sampling-rate conversion is available on both inputs.
BNC connectors carry word clock in and out/thru (with switchable termination). Also provided are an RCA jack for SMPTE in and three MIDI ports.
Control connections are ample, including a 15-pin DTRS remote control jack for use with Tascam's DA-series digital multitrack recorders, as well as a 9-pin RS-422 and a 9-pin GPI connector for control of external devices. There are also connections for the optional meter bridge and a ¼-inch external footswitch jack (which was nonfunctional in version 1.6).
The rear panel contains two slots for option cards, including the IF-TD/DM ($249), which provides eight more channels of TDIF I/O, and the IFAD/DM ($249), with eight channels of ADAT Lightpipe and an ADAT sync connector. Also available are the IFAE/DM ($299), with eight AES/EBU I/O channels; the IF-AN/DM ($499), for eight additional channels of analog I/O; and the IF-CS/DM ($299), which allows two DM-24s to be cascaded.
Another option is the MU-24 ($949) meter bridge. Although the metering in the DM-24's onboard display is usable, it's so small that I strongly recommend budgeting for the MU-24 when you figure the cost of the mixer. The onscreen channel metering and the pair of 12-LED ladders that monitor stereo output are adequate in a pinch, though. The MU-24's meters don't line up directly above the corresponding channel strips, so you can't check levels with a quick glance; you must look at the legends.
SCRATCHING THE SURFACE
The mixing surface contains 16 channel strips, each with a 100 mm motorized, touch-sensitive fader; an LED that indicates automation status or level overload (with programmable source and OL level); and Mute, Select, and Record Enable buttons. (The Record Enable buttons function only when the DM-24 is used for machine control.) To solo a channel, you must press the latching Solo button, which turns the channel mute buttons into channel solo buttons. Soloing is a frequent task, and I found that scheme awkward.
Four stepped, infinite rotary encoders above the faders allow you to adjust EQ or aux send parameters for a selected channel. Surrounding each encoder is a ring of 11 LEDs that indicate the parameter's value. Sometimes an encoder uses multiple LEDs; for instance, the Q pot uses a spread of LEDs to give a visual indication of bandwidth. I really love that approach, because it provides an immediate and intuitive read on several parameters simultaneously.
There are more possible parameter values than LEDs, however, so you need to look at the LCD to read exact values. What bothered me more than that was the fact that the encoders default to large value increments, such as 1.5 dB steps in EQ gain. You can obtain finer increments (such as 0.5 dB EQ gain steps) either by holding down the 2ND F key while turning an encoder or by changing a preference from Coarse to One Step in the setup options. It would be more useful if One Step were the default setting, as its functionality isn't at all obvious. In fact, I initially thought the DM-24 was incapable of fine parameter increments.
Four more encoders, called Pods, are soft controls you can use to edit the contents of the main display in conjunction with the four buttons just above them. The Screen Mode buttons, located to the right of the display, give you access to a function set that includes EQ, dynamics, effects, and I/O mapping. Those buttons also serve for numeric entry.
You navigate through the main display using either the four arrow keys to the right of the Pods or the scrub wheel to the right of the arrow keys. In most cases, the arrow keys and scrub wheel step through parameters on the page, and you adjust their values with the Pods. To the right of the Screen Mode section are four keys for creating, editing, and accessing the DM-24's ten location memories.
To the left of the display, it's nice to see dedicated sampling rate and external clock LEDs. The channel-assign buttons direct the channel's output to the eight mix buses or master stereo out in odd/even pairs, and a Direct button routes the signal to outputs on an option card or TDIF connector for the first 16 channels only.
HIT THE BOOKS
A DM-24 Library is a snapshot of commonly used parameters such as EQ or effects settings. Located to the left of the display, the Library buttons are designed for quick access to Library presets. They work with the active Library, which you can select from the Options/Setup screen. The buttons provide a fast way to grab Preset or User settings, but their usefulness is greatly limited by having to go to an Option screen to activate a Library type. It would be better if the active Library were sensitive to the context supplied by the onscreen parameters, or if you could change it with a simple modifier keystroke (such as 2ND F and EQ). Instead of using those controls, I typically accessed Libraries from the appropriate parameter edit screens.
The Module button accesses the channel functions: EQ, dynamics, aux sends, assignments, and configuration. Pressing a channel's Select button does not automatically bring up that screen as I wish it would; you must press the Module button or hold the Select button down for about three seconds.
The far-right top of the panel contains knobs for solo, monitoring, and communications. You'll need an external switcher if you want to switch between sets of speakers, because the DM-24 has no facility for that.
LAYER UPON LAYER
Like many small-format digital mixers, the DM-24 uses layers to make 16 sets of faders and channel buttons serve for all of the mixer's fader needs. The three layers are 1 through 16, 17 through 32, and Master, which includes both bus and aux masters.
The layer-select and machine-control buttons are very conveniently located close to the user, making it easy to anchor your arm on the armrest and operate them. Above those is a large blank area where I wish Tascam had located the navigation controls — the scrub wheel, arrow buttons, and Enter key. Because those frequently used controls are located so high on the panel, I inadvertently pressed the machine-control buttons under my forearm whenever I tried to operate them with my arm on the armrest. I'm not the only user to notice that; version 2 software will include a Transport Lock feature to specifically address the problem.
The DM-24's machine-control capabilities are unusually comprehensive for a mixer in its price range, but given how many recorders Tascam has manufactured, perhaps that shouldn't be surprising. In addition to transport controls, various buttons control recorder-input monitoring, auto-punching, and automation modes. Accessing the machine-control buttons is extremely quick and easy. Combined with the Record Enable buttons on the channel strips, those controls enable truly professional-level speed in sessions; you rarely need to move away from the mixer except to access outboard processors.
As you might expect, Tascam supports its entire DA-series of multitrack tape transports, as well as the MX-2424 hard-disk recorder. That support includes the ability to edit the recorders' setup parameters and to control open- and closed-loop devices such as pro-level videotape recorders and time-code DAT recorders. If another mixer in the DM-24's price range has its level of machine control, I sure haven't seen it. Kudos to Tascam for the thoroughness of the implementation.
Each of the DM-24's 32 channels features four bands of fully parametric EQ and a compressor, and the first 16 channels have an expander/gate. Six aux buses feed either the internal effects or four assignable sends, and the eight mix buses feed the TDIF, ADAT, or option slot outputs. You can insert three stereo compressors into any three pairs of aux, mix, or master L/R buses.
Analog outputs for the mix buses are available only if an analog I/O option card is installed in one of the slots. Unless your surround monitoring system happens to have digital inputs, you'll need the option card if you want to feed a surround monitoring system.
Each of the 32 channels can receive a signal from either an input or a return. Inputs are chosen from the analog mic/line inputs, stereo digital inputs, assignable returns, or internal effects returns. Returns for the 32 channels are from the TDIF or ADAT connectors or one of the option cards. (With the software version I reviewed, channels 25 through 32 receive their signals from inputs only, not returns; according to Tascam, that will be changed in version 2.)
The assignment scheme's inability to arbitrarily map buses or direct outs to outputs made it difficult to route things as flexibly as I wanted, causing me some inconvenience in session. In the end, I made a number of snapshots that changed nothing other than routing of the outputs, the inputs, or both. According to Tascam, version 2 will allow you to map any return to any channel.
Most of the time, you'll probably use at least two aux send buses to route signals to the DM-24's two onboard effects processors. They provide a selection of Tascam effects, including guitar compressor, distortion, compressor, exciter, de-esser, phaser, delay, chorus, pitch shifter, and flanger. Tascam has also licensed reverb algorithms from TC Works, as well as Microphone Modeler and Speaker Simulator from Antares. You can use the two processors independently or in series. The selection of presets is substantial.
The Tascam effects, while serviceable, are not high quality. The TC reverb can sound quite good, but I had to search several presets to find one I liked on my drums (Bathroom was the winner).
A wet/dry mix parameter is available on all effects except Antares; oddly, Tascam recommends leaving it at 100 percent wet all the time. Otherwise, latency would cause artifacts if the dry signal were mixed in. Tascam explained that the recommendation applies only to using the effects in Send/Return mode and that the wet/dry mix is imperative when using effects as inserts — a distinction not noted in the manual. It would be helpful if the Mix control disappeared, or at least was grayed out, when the effect is used in Insert mode.
Configuring the effects was sometimes confusing. Although the effects type appears on two editing screens, you can't edit it directly; you must load a new preset to change the effects type. Recalling a preset does not immediately take you to the editing screen for that effect; you must press the Effect Screen Mode button each time. That's not very efficient, especially when you're combing through dozens of presets.
The DM-24 is capable of operating at 88.2 or 96 kHz sampling rates, but with restrictions. As in most current devices, high-sampling-rate (HR) mode halves the DM-24's resources. For example, HR mode reduces the number of available channels to 16.
In addition, you must cycle the mixer's power to switch to and from HR mode, which loses all the mixer's configuration settings. I understand why you'd lose parameters that apply to channels and other resources that disappear when you switch to HR mode, but I don't see why MIDI Control Change (CC) mapping has to be altered. In a commercial studio with a minimum of time between sessions, it would be a pain to reconfigure so many parameters.
I/O is where things really get sticky. The most significant problem is the lack of a low-cost multichannel digital interface for high sampling rates; it's an industrywide dilemma, and Tascam is certainly not to blame (see the sidebar “HR Department”). I had no way to transfer multichannel HR data to my computer, so Tascam generously loaned me an MX-2424 to evaluate the DM-24's HR operation. Nonetheless, I ran into trouble.
I was trying to record bass and drums on the MX-2424, using ten tracks for drums, one for bass, and one for click (which I had previously laid down). Contrary to statements in the DM-24 owner's manual, only eight mic/line inputs were available. Combined with the two assignable returns in HR (down from the usual four), that gave me only ten analog inputs — one shy of what I needed. Because the 2-channel digital inputs were disabled in HR, it was also impossible to return existing 48 kHz tracks from my sequencing software (MOTU Digital Performer) for monitoring.
Other than the misrepresentation in the manual (which Tascam assured me would be remedied in the next printing), I don't want to criticize the DM-24 for my problems. At this time, however, HR operation isn't practical except for applications that use a limited number of channels.
The DM-24 sports a fine, full-featured automation system. Motorized, touch-sensitive faders are a very responsive interface for mixing. The DM-24's faders perform well and have a smooth feel, without which the touch sensitivity would be largely wasted.
You can automate all of the standard channel functions — level, mute, EQ, dynamics, and aux sends — as well as snapshots and Libraries. You can't dynamically automate the effects, however.
The DM-24 automation includes features usually found only in high-end systems, such as writing automation from where you stop to the end and staying in record even after time code is interrupted (which generally kicks automation systems out of record). Other useful features include a Rehearse mode and a time-out scheme for the Pods that makes them act more as if they were touch-sensitive.
Tascam clearly knows that the most significant tasks in automated mixing have to be done either very quickly or simultaneously, and that those actions will be performed repeatedly. For example, using machine control and switching automation modes must be fast, and enabling or disabling automation on all channels must be simultaneous. On the DM-24, good placement of top-panel automation controls and a streamlined scheme for configuring automation ably support those needs.
The system's Achilles' heel, however, is its limited memory; you can store only seven mixes. I didn't use the automation enough to get a feel for how quickly a single mix's memory fills up, but I tend to use a lot more than seven mixes for a song because I save a version after almost every tricky move. In addition, there's no list or offline automation editing, so moving a mute that's only slightly off in time might require numerous attempts.
The DM-24 is capable of surround mixing, but it has some familiar limitations you might expect in a small-format mixer. Surround mixing burns a lot of routing resources, in terms of both buses and panning. Generally, the surround mix buses are derived from the regular group mix buses, the aux buses, or both. The DM-24 takes the group mix approach and supports stereo, quad, LCRS, and 5.1. For each of the surround modes, you can choose from several output-channel orders. Because the buses carry the surround mix, you can easily route them to the TDIF and Lightpipe ports, but if you want to monitor from the DM-24, you'll need an analog I/O card in one of the option slots.
Surround panning uses the two-knob method (left/right [L/R] and forward/back [F/B]), so dynamic surround panning is not the DM-24's strong suit. Version 2 should greatly improve the surround panning, offering improvements that include circle and square patterns, but there is no provision for a joystick or other physical x-y controller. The panning controls include both L/R and F/B divergence controls (which the manual describes without naming). Feeding any kind of surround reverb or effect would be difficult, but the assignable sends might get you most of the way there. None of the onboard effects are tailored for surround.
In addition to sending MIDI Machine Control (MMC) data, the DM-24 can send and receive Program Changes, CCs, and SysEx data. You can set the faders to send the same CC over all 16 MIDI channels, and the Pods can send several different CCs over a single channel. The Control Change Table screen allows detailed mapping of any fader, pan control, or mute button to send and receive any controller number on any MIDI channel.
The DM-24 uses MIDI to install operating system upgrades, by means of playing Standard MIDI Files (SMFs) into the mixer. I used that capability to upgrade from version 1.1, which was installed in the mixer when I received it, to version 1.6, which I downloaded from Tascam's Web site.
Upgrading proved more troublesome than I expected when I read in the manual, “The ONLY Mac application Tascam supports for upgrading the DM-24 via MIDI is MIDIGraphy version 1.4.3.” Unfortunately, MIDIGraphy is an old shareware program that doesn't directly support USB. When I couldn't get MIDIGraphy to work without at least installing OMS, Tascam assured me that I could use Digital Performer to play the upgrade SMFs. That was also problematic, because I had to keep slowing the tempo for the data to load correctly. Through trial and error, I finally succeeded with a tempo just over 50 bpm.
TRANSFIXED IN THE MIX
I spent time both tracking and mixing on the DM-24. One thing is certain: this box is absolutely packed to overflowing with features. The DM-24 has so many attributes that I haven't even mentioned standard features such as fader and mute groups, but they're in there. The DM-24 sounds great, too. The mic preamps are clean and quiet, the A/D/A converters sound fine, and the EQ and dynamics do the job (I got a great kick-drum compressor going).
The faders are great and I like the Pods, but the user interface has a few rough edges. For example, although the placement of the machine-control and automation controls offer outstanding functionality, the scrub wheel and cursor keys simply miss the boat. Despite having many more hits than misses, the DM-24 carries that “good news/bad news” theme throughout its design. It has great automation features, but it's lacking in memory and automation-editing capabilities. It handles surround mixing, but with limited dynamic movement. Fortunately, the version 2 software should address the most egregious problems.
Some downsides, including fewer analog inputs at high sampling rates, will make certain applications a struggle. Others, such as the lack of mic/line switching, are simply idiosyncrasies to which you can grow accustomed.
The scales are definitely tipped to one side, however: the good far outweighs the bad. The wealth of digital I/O, the excellence of the machine-control and automation features, and the touch-sensitive faders are enough to earn the DM24 a place in many studios.
Considering all the DM-24's meat-and-potatoes functions, extras such as high-sampling-rate operation, price, and small footprint, it's obvious that Tascam continues to have a strong talent for combining functionality and affordability. That's an attractive formula indeed.
Larry the Othought he was leaving a message on an answering machine but is, in fact, painting polka dots on a freight train in Bulgaria.
DM-24: THE NEXT GENERATION
In version 2.0, any manufacturer has the chance to show a mature realization of its product. The DM-24's software upgrade, scheduled to ship by the time you read this, should significantly improve on the original release.
The first major improvement will be in surround-sound functionality. In version 1.6, the Pattern function generates only diagonal corner-to-corner movement; 2.0 will add circle and square patterns, as well as the ability to jump to key locations such the soundstage's corners and centers (front center, rear center, and the center of the room). You will also be able to use cursor keys and the jog wheel to move through the surround space.
Some important additions will be made to the DM-24's MIDI capabilities, including Mackie HUI emulation, which should be very beneficial for some users. A MIDI-only layer for the faders and buttons will be added, contributing even more features for controlling DAWs. Previously nonfunctional features will work in 2.0; for example, the GPI connector will be active, and the footswitch will perform any of 13 functions.
A host of version 1.6's shortcomings will be addressed in 2.0, and many small, utilitarian trimmings will be added. You'll be able to route effects returns directly to the stereo outputs. A Transport Lock mode will prevent inadvertent button presses when you rest your arm on the console while working near the display. You'll be able to use channels 25 through 32 as returns as well as inputs. You'll be able to flatten individual EQ bands with a simple keystroke. Additional enhancements in 2.0 will include an internal MIDI Time Code generator.
Faders(17) 100 mm stroke, motor-driven, touch-sensitiveEQ(32) 4-band parametricSampling Rates44.1, 48, 88.2, 96 kHzSampling Resolution24-bitAnalog Inputs(16) balanced XLR mic; (16) balanced ¼" TRS line; (4) balanced ¼" TRS returns; (2) RCA 2-track returnsPhantom Power+48V, switchable in blocks of (4) channelsAnalog Outputs(2) balanced XLR mains; (2) balanced ¼" TRS monitors; (2) RCA studio monitors; (4) balanced ¼" TRS sends; (2) ¼" stereo headphoneAnalog Inserts(16) ¼" TRS channel inserts; (4) ¼" TRS assignable inserts; (2) ¼" TRS L/R insertsCoaxial Digital I/O(2) XLR in; (2) XLR out; (2) RCA in; (2) RCA out; all switchable from AES/EBU to S/PDIFTDIF I/O(24) channels; (3) 25-pin D-sub; 24-bit word lengthADAT I/O(8) channels; (2) Lightpipe optical connectors; 24-bit word lengthWord Sync I/O(1) BNC in; (1) BNC out/thruMIDI I/OIn, Out, Thru/MTC OutAdditional I/O(1) SMPTE RCA in; (1) ¼" footswitch in; (1) DTRS remote 25-pin D-sub out; (1) meter bridge 25-pin D-sub out; (1) RS422 9-pin D-sub; (1) GPI 9-pin D-sub; (1) IEC ACEffects Processors(2) stereo, 24-bit multi-effects (mic modeling, speaker modeling, reverb, chorus, delay, distortion, compressor, guitar compressor, phaser, pitch shifter, flanger, de-esser, exciter)Dynamics Processors(16) gate/expanders for channels 1-16; (32) compressors for channels 1-32; (6) compressors assignable to aux sends, bus masters, and stereo outputsFrequency Response20 Hz-20 kHz, +0.5 dB, -1.5 dB or betterTotal Harmonic Distortion<0.013%Noise-68 dB or lessDisplays(1) 320 × 240-pixel backlit LCD; (2) 12-segment LED metersPowerinternal 120/230/240 VACDimensions22.9" (W) × 7.8" (H) × 25.9" (D)Weight45.1 lb.
The world is in dire need of a low-cost, widely accepted, high-sampling-rate, multichannel digital interface. As of this writing, though, such a beast doesn't exist. High-end professional users might have access to multichannel audio digital interface (MADI) I/O devices, but they're much too expensive for the personal-studio market.
The two most commonly used multichannel digital interfaces in the personal-studio market — Tascam TDIF and Alesis ADAT Lightpipe — are supported by the DM-24, though only the TDIF can be run in HR. Only a handful of devices use those two formats at high sampling rates. They accomplish that feat by halving the number of channels carried on each connector; instead of eight, you get four. Tascam's MX-2424 hard-disk recorder is one device that works that way.
Until a more economical and efficient system becomes universal, the most practical HR method is multiple AES/EBU streams, which can carry data either by carrying a single channel instead of the normal two or by running at twice the normal speed. Although several devices are capable of using AES/EBU in HR, that method is cumbersome; in the best-case scenario, at double-speed, at least four XLR connectors (or a DB25 with a split-out cable on some devices) are needed to carry eight channels of data.
FEATURES4.0EASE OF USE3.0AUDIO QUALITY3.5VALUE4.0RATING PRODUCTS FROM 1 TO 5
PROS: Large feature set. Excellent automation and machine-control implementations. Touch-sensitive faders. High-sampling-rate and surround capabilities. Onboard effects.
CONS: A few awkward user-interface choices. Very limited analog I/O in HR mode. Mediocre Tascam effects.
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