Are you ready for the 24-bit HDR challenge? At last year's Winter NAMM show, I paid close attention to the crop of unreleased compact 24-track hard disk

Are you ready for the 24-bit HDR challenge?At last year's Winter NAMM show, I paid close attention to the crop of unreleased compact 24-track hard disk recorders (HDRs). One such unit was the relatively inexpensive Tascam MX-2424, which was developed in association with TimeLine, a company known for its high-quality synchronization devices and digital dubbers. When this HDR became the first of its kind out of the gate, I jumped at the chance to review it.

I set aside a couple of days to acquaint myself with the MX-2424, figuring that would be more than enough time to get a grip on new technology. But my first glance at the "quick reference guide" - a four-panel, 8 11/42-by-11-inch booklet printed on glossy card stock - should have clued me in that this was no simple plug-and-play machine. After scanning the manual for a half hour, my analog brain was swimming from the possibilities of a recorder with two dozen 24-bit tracks, onboard cut-and-paste editing, looping and auto-record, external computer control, DVD-ROM and tape backup, and virtual tracks. This is one powerful machine and its arrival at Guerrilla Recording was a loud wake-up call that catching up to the latest digital recording technology was going to require some effort.

STORAGE UNITAlong with the review unit, Tascam supplied six D-sub-to-11/44-inch TRS analog snakes and an ADAT-optical digital I/O module. An AES/EBU I/O module with input sampling-rate conversion is also available, as is a Tascam TDIF-format I/O. All I/O cards are optional equipment, supplied at additional cost. It is interesting to note that Tascam, one of the biggest supporters of the personal-studio revolution, has broken with tradition by not offering any -10 dBu consumer-level analog I/O in this professionally oriented package.

An internal 9.1 GB drive comes standard with the basic MX-2424 package, and a front-loading drive bay can be configured to accept optional SCSI hard drives, DVD-RAM, and Travan tape-backup devices. (Since this review was written, Tascam has released a software upgrade, version 1.10, which is included on all shipping units. The upgrade allows access to drive volumes much larger than 9 GB, as well as to Broadcast Wave files and FAT-32 drive formatting. HFS+ for Mac volumes beyond 9 GB were scheduled to hit the market in November.)

The test unit also included a CD-ROM (Mac and Windows compatible) containing MX-OS 1.02 system software, ViewNet graphical-user-interface software for Mac and PC, an owner's manual, a Smart Media card, and IEC and drive power cables.

IT AIN'T HEAVY, IT'S MY HDRAfter surveying the accessories, I hauled the MX-2424 out of its oversize shipping box. Although not particularly heavy, the unit is bulky. At 17 inches square, it may be too deep to fit in some portable road cases.

The MX-2424's 4U rack-mount front panel is remarkably well organized considering that there are 73 buttons (many with dedicated status lights), 20 additional status lights, 24 channel meters, a shuttle wheel, a Smart Media card slot, a blank drive-bay panel (removable for drive installation), and an AC power switch. The LCD is small - 3 inches wide and less than 31/44 inch high - but sufficient to display two lines of text.

All connections - I/O, synchronization, remote, MIDI, and computer - are made on the rear panel, which is also where the user-installable I/O cards go. The absence of a single control or switch on the MX-2424's back panel underscores the device's professional nature.

When I booted up the MX-2424, the internal hard drive was mounted and apparently ready to record within 15 seconds. Fan noise was audible at a level that could be a distraction, at least during mixdowns and critical listening. Unlike earlier Tascam DA-series recorders, the MX-2424 is vented by a fan that gently pushes air out of the unit, rather than sucking air (and dust) into the case.

LE MENUThe manual has no getting-started section, so I began at the Menu Operations chapter and scrolled through the nine menu banks that govern software-based switching. The basic banks, which you access through numerical buttons or up/down scrolling, are titled as follows: Rates and References, Bus Controls, System Controls, MIDI, Input/Output, Audio Controls, Disk, Project, and System. Some are quite simple, like MIDI, which has only one menu setting for the MIDI Device ID of the MX-2424. Likewise, the Audio Controls bank has just two punch-in/out settings: crossfade time and gapless monitoring. Banks such as System Controls (which governs a variety of transport and record functions) and the unrelated System (which controls familiar computer-related menus like default settings, date/time, machine name and ID, and network parameters) contain a dozen menu items each.

Numerical values in menus (for example, sampling frequency and variable-speed recording) are adjustable with up/down buttons and the shuttle wheel. When stored to the user-default setting, altered values will appear on startup. Ten additional user settings can be tailored for different engineers or set up on a project-by-project basis. Confusingly, the MX-2424 displays "Factory Default" as the recall setting, even when the unit has actually powered up with the user setting as the active default. Tascam says this "helps people have a common-ground starting point for each new project. Otherwise, he or she may start a new project while unknowingly reverting to the specific settings he or she had used on the last project." Still, a simple explanation would have eased my bewilderment and saved a lot of time.

For most studios, menu items other than I/O and sync switching (or looping and punching mode adjustments) will likely be of the "set it and forget it" variety, and won't be accessed on a daily basis. The manual is generally helpful in this regard, as it explains most software-based functions in concise, straightforward language. One exception is the section on the track-function keys: there is no explanation of the significance of these important controls (Record Select, Input, and Edit), nor are there any practical suggestions for their use. They are described only as determining "which function will be applied to the track/tracks when selected by the individual track selection keys." Navigating the steps between the MX-2424's Auto-input, Record Select, and Input modes was initially baffling - despite my familiarity with multitrack recorders. This confusion stemmed from an attempt to rehearse a bass guitar part along with previously recorded tracks, record the part, and then listen to it. (The manual also fails to provide any clue to the subtleties of another important control, the combined Auto-input/All-safe key.)

A LA MODEThe MX-2424 has two modes for recording to hard disk: Non-Destructive and TL-Tape. In Non-Destructive mode, the MX-2424 records and stores up to 999 virtual tracks, any 24 of which can be "real" at one time. These virtual tracks, in keeping with convention, can be loaded into or out of any track for comparison purposes, and are also available for editing with full undo/ redo capability.

TL-Tape mode mimics the operation of an analog-style recorder, recording over and effectively erasing previous sections of audio from the hard drive. In this mode, editing is not an option, although virtual tracks are still available. So what's the point? Well, TL-Tape mode does offer the advantage of creating tracks as contiguous Sound Designer II files, which can easily be imported into popular computer-based editing programs such as Pro Tools and Digital Performer. (The manual also neglects to mention that you can't set up a user default for saving recordings done in TL-Tape mode - another omission that left me scratching my head.)

I eventually set the manual aside and tried some simple recording scenarios. Recording from an analog source proved a snap, thanks to the familiar set of transport controls. But I hit a few snags on my first foray with a digital input, and eventually had to go back to the manual for clarification. (Thankfully, a new manual is being produced soon, according to Tascam, and the company will add tutorial information to its Web site.)

File management is another topic that could use some explaining in the manual - an instructional chapter about organizing tracks, songs, and projects would be helpful for first-time users. Fortunately, the Proj key's functions, which include loading, renaming, and deleting projects, as well as performing backup, restore, and copy functions to other drives, are thoroughly detailed on an entire page of the quick reference guide. Identifying and renaming the previous sessions' recordings proved easy enough; however, alphanumeric scrolling in an LCD window is a bit of a drag, even with a shuttle wheel.

DEEP DIGITALNaturally, the MX-2424's multitude of I/O, clock, and sync sources makes master-clock selection a necessity; however, some of the selection processes are needlessly complicated. Recording from a 2-track digital source, for example, requires accessing one menu to locate and select the 2-channel digital input; another, nonadjacent menu to specify S/PDIF as the 2-channel source; and a third menu to specify the 2-channel input device as the sample-reference clock source - a rather cumbersome button-pushing sequence.

At the same time, flexible digital switching distinguishes the MX-2424 as a fully professional unit. However, the manual covers this topic insufficiently and doesn't serve the needs of novice users. For example, engineers used to working only with DAT, CD-R, and so on may need a reminder that they must first set a master-clock source when recording from an external digital device. For less experienced users, clocking is a complicated issue. Misunderstanding or ignoring its significance can result in various types of audio degradation.

SMOOTH MOVESAfter straightening out these digital details, I was happy to discover that toggling through the connected analog, S/PDIF, and AES/EBU digital inputs was surprisingly smooth, with no muting or nasty digital glitches. I heartily applaud the MX-2424's ability to route standard S/PDIF and AES/EBU stereo signals to or from any odd/even pair of tracks. This feature should prove tremendously useful for adding instruments to a finished stereo mix, archiving 24-bit mixes, and even doing simple assembly edits for a multisong project with the aid of the ViewNet graphical- user-interface application.

Users can run ViewNet - which Tascam calls a "visual editing environment" - if the MX-2424 is linked to a host computer through the 100 MB Ethernet port. To run this application on a PC, you'll need a Pentium II/400 MHz with 64 MB of RAM, Windows 98, and 100Base-T Ethernet. The minimum system requirements for the Mac are a Blue and White G3 or iMac/400 MHz, 96 MB of RAM, and 100Base-T Ethernet. But before acing the environment, prepare yourself for a sizable printing task: the 210-page ViewNet manual is available only as a downloadable PDF file from Tascam's Web site. The next step is getting the computer to see the MX-2424. This requires manually entering the MX-2424's individual IP address (found in menu 950) into the computer's TCP/IP window. Make sure the cable you're using is a crossover type rather than a straight Ethernet cable (that is, unless you're on a network hub).

ViewNet represents recorded tracks as audio blocks, with useful waveform-style editing promised in a future software revision. ViewNet also allows computer-keyboard control of a host of editing, naming, and virtual-track options, along with central network management for multiple-machine arrays. (Note that the Ethernet connection is also where you load MX-2424 software upgrades, which are posted to the Tascam Web site.)

MISTER EDITIn addition to several recording functions, such as locate (up to 99 locate points can be stored in memory), loop, rehearse, auto-record, and auto-punch, the MX-2424 also offers avariety of cut, copy, and paste editing capabilities - enough to accommodate most anyone's working methods. All of these functioned as described, and here the manual was truly helpful, offering clear diagrams and limited applications for most of the operations.

Editing without ViewNet is not easy. The onboard LCD is limited to two lines of 20 characters each, with the first line showing the location of the play head and the second either an In or Out point - you can't view the In and Out points simultaneously. In addition, although there are 100 levels of undo/redo available for edit operations, onscreen undo steps are not identified individually, except by a numerical sequence. Therefore, a pencil and paper are handy once you get beyond three or four undo operations. If you need to keep track of more than a few projects, ViewNet is the way to go. It offers tracking of redo history, project and track naming, and the more memory-intensive file-management functions. Though ViewNet does not provide waveform editing, this feature will be available in version 3.0, which is slated for release in the spring.

Some noteworthy editing features include an operation Tascam refers to as "rendering," whereby the empty spaces between multiple chunks of edited audio are eliminated to form a single, coherent track, and track "nudging," which is the ability to move a track by increments of a millisecond or less, to enact subtle changes in the groove. Reverse - that is, playing the audio backward - is another interesting option.

PREACHING TO THE CHOIROf course, the audio quality of a digital medium is ultimately at the mercy of its A/D and D/A converters. To get a sense of the converters' sound quality, I compared them with those of an original Alesis ADAT and a high-end Apogee PSX-100 recording into a 16-bit Panasonic SV-3800 DAT recorder.

Copying ADAT tracks through the MX-2424's ADAT-optical I/O ports came off without a hitch. I was struck by how robust the ADAT-recorded tracks sounded coming out of the MX-2424's D/A converters. A comparison of the program directly from the ADAT's analog outputs with the same program going digital in and analog out of the MX-2424 confirmed that it was easy to hear the improvements in the tracks' depth and listenability from the MX-2424's D/A converters.

Not surprisingly, the Apogee converters proved a more formidable challenge. Using a coincident pair of Neumann U 87 microphones through a Langevin Dual Vocal Combo preamp, I recorded an impromptu jam session assembled by trumpeter Darren Johnston directly to two-track, splitting the stereo-mic signals to feed both the MX-2424 and the Apogee PSX-100/ Panasonic SV-3800 chain.

Compared with the Apogee-converted tracks, the top octave - or "air" range - of the MX-2424 tracks sounded dull. The cymbals lost crucial upper harmonics and "ping," and room detail on trumpet and hi-hat ambience came across as veiled or simply missing. In a passage where an aggressive bass solo masked off-mic trumpet notes, the trumpet phrase came through with dramatic clarity on the Apogee/DAT recording. The acoustic bass sound captured by the MX-2424 was very warm, though a bit tubby, with a pronounced 200 to 800 Hz range that also brought toms forward in the stereo mix. Though the bass sounded good coming from the MX-2424, the instrument had more true low fundamentals through the Apogee converter.

Overall the MX-2424 made the group recording sound more intimate and up front by downplaying the contributions of the room. The Apogee/Panasonic DAT combo conveyed a wider soundstage with more depth and openness, as well as increased realism and detail in room ambience. (These impressions were confirmed on the D/A side too. For this comparison, I toggled between the MX-2424's D/A converters and the Apogee PSX-100's converters, fed by the Tascam's AES/EBU output.)

Of course, it's understandable that a pair of $3,000 converters would outperform those in a 24-channel I/O box retailing for only $1,699. In that regard, the Tascam converters are a great deal, considering the cost of using 24 channels of high-end outboard converters.

The Tascam converters certainly have a characteristic sound that's closer, tighter, and warmer than most. These attributes could prove attractive to studios doing a lot of rock, hip-hop, R&B, and pop music. Though these converters are definitely an improvement over those found in first-generation 16-bit MDMs, to my ears they are not quite audiophile quality, as Tascam claims. I would prefer pairing the MX-2424 with higher-end outboard converters - especially for recording jazz and classical music.

HEAD OVER HEELSDespite my lukewarm feelings about the sound of the MX-2424's converters, I fell in love with several of the unit's features, such as instantaneous rewind and locate. And how about the Tascam's potential for 24-bit mixes stored alongside the multitrack master, or as virtual tracks, not to mention the ease of tucking the unit under my arm for those little excursions from the recording studio to the mastering room?

The MX-2424's ability to do real-time sampling-rate conversion is another big selling point. To test this DSP-based feature, I converted a 48 kHz signal (applied at the S/PDIF input) to 44.1 kHz. The MX-2424 did a decent job, with very low latency and no audible harshness or artifacts added to the source. This is no small feat. Understandably, after sampling-rate conversion, the highs above 10 kHz were dulled slightly; however, there was also a noticeable loss of bass frequencies (as compared with the original 48 kHz DAT source).

IN A REMOTE CORNERThe RC-2424 remote control arrived toward the end of the evaluation period. Installation was easy, requiring only a simple hookup of the control cable and power supply, and a 2-minute wait for software exchange. The remote's faceplate follows the general look and layout of the main unit, with some notable exceptions: the LED meter ladders have been replaced with four status lights (Input, Overload, Select, and Record); a section of multiple-machine-select and record-status buttons has been added; and a row of macro keys allows you to save complex edits and set up keystroke sequences as single-button operations. In addition, some location and looping keys have been moved around and enlarged to the same size and prominence as the transport controls. Considering all these changes, it's too bad Tascam didn't find a way to make the RC-2424's LCD a little larger.

An Alesis LRC connected to the footswitch jack can also be used for transport control of the MX-2424. However, the LRC must be connected before booting up the MX-2424 - another point that is missing from the manual. The LRC allowed one-button control of the Tascam's auto-input and all-input status, and worked even when the RC-2424 was attached. I'd rather use the RC-2424 and LRC in tandem, even though triggering the auto-input from the LRC did prompt the occasional - and inexplicable - "Loop too short" error message.

ONE-STOP SHOPPINGThe MX-2424 is an extremely powerful and versatile 24-track hard disk recorder with good sound quality, a vast feature set, and a very attractive price. The unit provides a variety of cut-and-paste editing functions; 99 locate points; 100 levels of undo/redo; multiple looping, rehearse, and auto-record functions; backup to hard drives, DVD-RAM, or Travan tape; word clock, MIDI, SMPTE, and video sync; software for onscreen computer editing; a 9.1 GB hard drive; and many other features. Optional 24-channel I/O modules allow for 24 tracks of 16- or 24-bit recording, as well as TDIF, ADAT-optical, and AES/EBU connections, and there is also an optional remote control. In short, there is little that this HDR can't do.

However, this groundbreaking product could have been more user friendly. Moreover, little effort has been made to provide tutorial materials that would let novice engineers, recent analog-to-digital converts, and personal-studio-level recordists take advantage of its vast potential. Getting up to speed on this HDR was a huge challenge. Even after constant grappling with myriad multiple-button procedures (which initiate all but the simplest of the unit's functions), I still didn't develop a feel for this machine.

Navigational complexities aside, the MX-2424 sounds good, and with software revisions and/or souped-up converters, it has the potential for sonic greatness. For the most part, Tascam's flagship HDR cuts an impressive figure as a do-it-all unit for the digital age, with no major compatibility, expansion, or platform problems. There's an interface for every imaginable analog, digital, and visual media need; the unit is reliable and crashproof; and the price is right.

Seriously considering buying an MX-2424, but would like more advice? Fortunately, you don't have to rely solely on one person's opinion. The Tascam Web site (www.tascam.com) has an MX-2424 user group you can check out to monitor user feedback. As evidenced by the user group, the MX-2424 is very much a work in progress, with a lively community of owners and responsive Tascam staffers working together in an open forum to iron out wrinkles and implement changes to both software and hardware. In frequent visits, I have been amazed - and humbled - by the depth of understanding that many contributors display. I sympathize with individuals who are having problems and who don't have the patience to participate in a process that some have equated with product testing. A few of these folks are frustrated by obscure problems or nonimplemented features; in addition, there have been numerous complaints about the manual.

The MX-2424 is a modular system that can be customized and expanded to match the needs of any personal or professional recording studio. The heart of the system is the MX-2424, which retails at $3,999. For multitrack work, at least one of the following modules must be installed:

IF-AN24 (24-channel analog I/O module) $1,699IF-AE24 (24-channel AES I/O module) $999IF-AD24 (24-channel ADAT-optical I/O module) $499IF-TD24 (24-channel TDIF I/O module) $499

The RC-2424 ($1,499) remote control unit is a handy extra that allows remote location of the MX-2424, and even includes a few features not found on the main unit.