There was a time when giants walked the earth and everyone made records on 2-inch, 24-track analog tape. During the decades in which multitrack recording
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There was a time when giants walked the earth and everyone made records on 2-inch, 24-track analog tape. During the decades in which multitrack recording

There was a time when giants walked the earth and everyone made records on 2-inch, 24-track analog tape. During the decades in which multitrack recording dominated audio, people developed working methods based on the characteristics of the storage medium: tape machines are mechanical and linear.

With the advent of the digital-audio workstation (DAW), many required recording skills changed. In addition the ability to work in a nonlinear fashion opened new doors for creativity. However, the interface between artist and machine was often less than intuitive.

In the personal studio, musicians want a recording device that is as fast and intuitive to use as a tape deck but with the advantages that DAWs provide. iZ Technology wants to be on those musicians' radars. (Some puns are not to be denied.) iZ's founders created the Radar hard-disk recording system in 1993. The Radar and its successor, the Radar II, were distributed by Otari until last year, when their deal expired, and iZ decided to carry on by itself.

Enter the Radar 24, a hard-disk recorder built to operate like an analog tape deck (see Fig. 1). The Radar 24 is a self-contained system that has a dedicated Intel 600 MHz Celeron Pentium III running the Be operating system; 24 channels of 24-bit analog I/O; TDIF, AES/EBU, or ADAT Lightpipe digital I/O; and a controller that bears a deliberate resemblance to a tape-machine transport controller.


Although the Radar 24 is built to record at sampling rates as high as 192 kHz, the 24-track maximum is available only at sampling rates as high as 48 kHz. The higher sampling rates decrease the track count proportionally: each time you double the sampling rate, you cut the number of tracks in half. If you record at 192 kHz, you will have only six tracks to work with.

As many as eight Radar 24 systems can be sample- and phase-locked through iZ's proprietary Radarlink to create a 192-track system. In addition, iZ created an integrated 48-track version of the Radar system.

The Radar 24 consists of a 43-pound, 4U chassis and the KC24, a PS2 keyboard with keycaps labeled with the Radar 24's functions. To get a DAW-like environment, hook up a USB mouse for audio scrubbing and a standard SVGA monitor for a display.

The review unit included the optional Session Controller ($1,195), which can be used with or without the KC24 keyboard, monitor, and mouse. Although the KC24 is entirely adequate as a controller, it's worth buying the Session Controller for its track-select buttons, scrub wheel, and superior layout as a machine controller. With the Session Controller in front of me, I never had an urge to use the keyboard.


At the far right of the chassis's rear panel are the slots into which the optional analog I/O cards fit (see Fig. 2). At the time of this writing, two kinds of I/O cards are available. Each comes as a three-board, 24-channel set: the Classic card ($1,695 per set) features 24-bit, 128× oversampling Delta Sigma A/D converters that support sampling rates as high as 48 kHz; and the Nyquist card ($2,995 per set), which has 96 kHz recording capabilities. The Super Nyquist 192 kHz card is not yet available, though the 96 kHz Nyquist card boasts 192 kHz D/A converters.

You can't mix and match cards. The review unit had a set of Classic cards, each carrying eight channels on a DB25 connector.

For digital I/O, the basic unit includes six DB25 connectors for 24 channels of TDIF compatibility. A 24-channel AES/EBU option is also available, and the ADAT Lightpipe I/O should be available by the time you read this. You can choose the AES/EBU or Lightpipe options to supplement the analog and TDIF I/O. The three connector types can be used simultaneously.

Two channels of AES/EBU and S/PDIF I/O are also included with the Radar 24. The formats are independent of the 24-channel option, but only one can be active at a time. However, you are not constrained to send or receive an odd/even pair: each input and output channel can be separately assigned.

In addition to the audio I/O, the Radar 24 has a comprehensive set of time code and sync connections. The unit can send and receive time code as LTC on XLR jacks or as MIDI Time Code (MTC) through the unit's MIDI jacks. The MIDI jacks include a Thru, which is a valuable commodity frequently left off of modular digital multitracks (MDMs).

Clock sync is available as word clock or video sync on BNC jacks. Video sync is confusingly labeled Sync Reference on the rear panel, as if word clock weren't a sync reference too. iZ is well aware of the installed base of the Radar I and II units, and it has put a good deal of effort into making sure that solid compatibility exists between the Radar 24 and its progenitors.

In addition to the Radar 24's extensive sync features, the device has an unusually high degree of integration with Soundmaster, a popular system in post-production for controlling multiple machines of various types. In fact, Soundmaster can control every function of the Radar 24 that can be executed from the Session Controller.

The Radar 24's computer connections include a standard SVGA monitor output, a loosely mounted PS2 keyboard connector (you might want to brace that connection), a parallel port, a 10/100Base-T Ethernet port, and the connectors for iZ's Session Controller and Radarlink system. Finally, there are Sony 9-pin, SCSI (for additional disk drives), and audio ground connections and a detachable IEC power cable. Those should be enough connections for most people.

The rear panel sports a loud fan; think vacuum-cleaner ambience. The Radar 24 also produces a prominent high-pitched whine after being on for a while, though sometimes it goes away after a few minutes. If you have a machine room, you will need to use a longer cable between the chassis and the remote than the one supplied. A 20-meter cable costs $150. If you don't have a machine room, you will be pleased to know that iZ will be using a quieter, more efficient fan by the time you read this.


The front panel is considerably more spare than the rear panel. It has a power switch, a removable hard-drive bay, a DVD-RAM drive, and a floppy drive. The hard-drive bay comes with a 9 GB, 10,000 RPM Seagate Cheetah drive, which yields more than 43 minutes of 24-bit, 48 kHz, 24-track recording time. iZ offers 18 and 36 GB drives as well.

You can add your own removable drives instead of buying them from iZ as long as you use approved drives (visit the iZ Web site for details). The company also reports that it's working with storage specialist Glyph Technologies on additional storage options, including RAID arrays.

The 2× DVD-RAM drive is used for backup by the onboard backup software. Although the Radar 24 ships with the DVD-RAM drive, you may opt instead for an 8 mm Exabyte tape drive or even a Sony AIT tape drive, which, though costly, is an excellent high-speed, high-capacity medium.


The Radar 24 is best controlled from the Session Controller (see Fig. 3). At 20½ inches wide and 10¾ inches deep, the Session Controller is not exactly the smallest DAW control surface available. That's because it has numerous buttons and a meter bridge with 20-element LED-ladder meters that indicate peak levels. You can also opt for 24- and 48-channel meter bridges.

Radar 24 Optional I/O Specifications

Analog I/OClassic audio board, Nyquist audio board, S-Nyquist audio board (3 boards, 8 channels each)AES/EBU I/Ostandard 2-channel; optional 24-channelADAT I/Ooptional 24-channelSampling RateClassic 32-48 kHz; Nyquist 32-96 kHz; S-Nyquist 32-192 kHzAnalog Input Level+4 dBu nominalAnalog Output Level+4 dBu nominalHeadroomselectable up to +24 dBuFrequency Response: Classic10-22 kHz (±0.5 dB @ 48 kHz)Frequency Response: Nyquist10-22 kHz (±0.5 dB @ 48 kHz); 10-45 kHz (±3 dB @96 kHz)Frequency Response: S-NyquistNot specifiedTHD+N (A/D/A): Classic0.004% max., A-weightedTHD+N (A/D/A): Nyquist0.003% max., A-weightedTHD+N (A/D/A): S-Nyquist0.003% max., A-weightedDynamic Range (A/A)Classic 101.5 dBA; Nyquist 108 dBA; S-Nyquist 108 dBADynamic Range (A/D)Classic 106 dBA; Nyquist 114 dBA; S-Nyquist 114 dBADynamic Range (D/A)Classic 104 dBA; Nyquist 109 dBA; S-Nyquist 109 dBA

Along the top of the controller are 48 numbered buttons used to select tracks for any function. With the exception of arming tracks for recording, the Radar 24 works in the reverse of the typical graphical user interface (GUI): in computer applications, you typically select materials and then specify the action to be performed. With the Radar 24, you choose the action and then use the track keys to select the tracks that will be acted upon. A red LED in front of each button illuminates to indicate that it has been selected. The LED blinks when a track is armed for recording.

The Radar 24's layout is not difficult to grasp. However, I was immediately reminded of just how wonderful it is to have large scalloped buttons that feel good to punch and over which you can run your finger to quickly select a group of tracks. With today's emphasis on compactness and pages of submenus, the sheer pleasure and efficiency of that button array has been forgotten. The physicality of the controller is, in fact, one of the Radar 24's major strengths.

Below the track-select buttons are three major groups of function buttons; a QWERTY keyboard with full-size keys; a 10-key number pad; arrow buttons; basic transport controls; a jog wheel flanked by four associated buttons; a two-character LED display showing the current project; and a 32-character, 2-line LCD through which the Radar 24's operations are executed.

One button group is made up of disk, backup, and project-management functions. The top row is reserved for eight programmable macro buttons, each of which can store a sequence of 128 key presses. Given how much the Radar 24's operation centers on button presses, the addition of macro keys adds a good deal of efficiency to the system. Version 3.05 of Radar 24's software lets you export macros to a floppy disk and load them onto another Radar system.

The second button group contains basic edit functions (Cut, Copy, Paste) and record functions (Cycle, Autopunch). The third group contains utilities such as Undo, sync enabling and disabling, and marker placement.

Many configuration functions are accessed through the menu system and by pressing the Menu/Prev button on the 10-key pad. Navigating the menu system on the Session Controller is logical but entails numerous keystrokes to plumb its depths.


Recording with the Radar 24 is so simple that it hardly requires description. Set your sampling rate, create a new Project, arm the tracks, press Record and Play, and off you go. When you need to set a punch point precisely, go into Jog or Shuttle mode and use the wheel. The Session Controller's jog wheel feels nice, which makes a big difference as you scrub through the audio.

Varispeed recording and playback ranges from +71 to -1,199 cents. In fact, Varispeed sounded so good that I found myself spinning the jog wheel just to hear the speed change.

I used the Radar 24 in my project studio to track drums, vibraphone, electric guitar, vocals, and synths. Vibes are always an acid test for microphones, preamps, and recording media because of the attack transients from the mallets and the pure tone of the sustaining bars. The overwhelming majority of vibe recordings I hear lack any softness in the attack and don't have the low-frequency warmth I hear when playing the instrument. I generally record the vibes with Earthworks SR77 mics because they capture the warmth and the softness of the yarn-covered mallets I use. But the final result varies noticeably with the recording medium. The Radar 24 beautifully captured the less aggressive quality I look for, whereas the transients stayed crisp and the harmonics clear.

Cymbals are another telltale source for the recording chain. Again, the Radar 24's sound was very satisfying. It captured the soundstage from the room mics quite well. Vocals also sounded nice and maintained their presence without harsh sibilant artifacts. The only sound the Radar 24 isn't well suited for is an extremely edgy and aggressive “buzz saw” electric guitar.

Throughout most of my work on the Radar 24, I engineered as I played, which is particularly indicative of how easy the system is to use. As long as the Session Controller was within reach, I could quickly and fluidly punch in, record, locate, and tackle other common tracking maneuvers.

iZ focused on making the Radar 24 great sounding, easy to use, and reliable. After recording with the system, I was left with the feeling that the company had admirably accomplished all three goals. I immediately liked the sound of the Radar 24: it has a smooth high end that doesn't suffer from phase problems; a full, round low end; and a distinct soundstage. I do regret that I was unable to record at the higher sampling rates.

Unlike many DAWs I've worked with, I never felt insecure about the Radar 24's stability: it never crashed. When I called iZ's 24/7 tech-support number at ten o' clock one night, the phone was answered in a few rings by a friendly and knowledgeable person who answered all my questions. That inspires additional confidence in the unit.


No recording system can do everything well, and the concepts embodied in the Radar 24 cut both ways. Each type of audio work has a set of actions the practitioner employs quickly and frequently. In music recording, those actions include locating, track arming, and going into and out of record. Speed is important, because it's all about capturing the moment.

For modern digital editing, the ability to manipulate files using a GUI is paramount. That's crafting the moment.

The Radar 24 does well in the first of those applications; the functions one needs quick access to while recording, such as the ability to drop auto-locate points or markers (as many as 99) on the fly, are well represented. Unfortunately, when you're done using a function, it's not as easy to make changes to your work. For example, once stored, the placement of the auto-locate points can only be modified by manually entering a new time code; it's not possible, for instance, to overwrite an auto-locate point with the countervalue. To accomplish that, you have to grab the counter of a new marker and swap it with the previous one.

I used the auto-locate points extensively, accumulating more points as I worked through the piece's sections. It would have been easier if I could have reused half a dozen points repeatedly.


iZ made the Radar 24 easy to use by sticking to a well-established approach that emphasizes a multitude of dedicated function buttons in place of a DAW's icon and menu approach. If the Radar 24 were merely a recorder, the Session Controller would be all you'd need.

But the Radar 24 has random-access and editing capabilities as well. To accommodate those features, iZ included the video monitor output and Radarview software. Although Radar 24's editing facilities are on par with other standalone hard-disk recorders, it is still not as facile for editing as a DAW.

For example, Radarview presents a zoomable waveform display of the tracks, a replica of the Session Controller's track display, and a parameter display area. The screen's layout, however, falls short of a DAW front end in a number of ways. To begin with, there is no mouse interaction within Radarview, neither from the PS2 mouse input on the chassis nor from the nonfunctional serial mouse input on the Session Controller. The only way to select waveforms, tracks, or edit parameter values is with the keyboard or the Session Controller.

The Radar 24 has no onscreen menus other than the replica of the Session Controller's display. There are large areas of unused screen real estate, yet the parameter displays are quite small. You can zoom in vertically until a single track dominates the screen, which is great, but you can't zoom to the sample level horizontally. Crossfades are adjustable in time as high as 100 ms, but the shape is not adjustable. You get the idea.

On the other hand, the time code display, essential for recording, can be seen from across the room, which is excellent. Additionally, the Session Controller has ¼-inch phone jacks for controlling punch, location, and Play/Stop with footswitches.

Despite that GUI brouhaha, the Radar 24 is what it's billed as: a great recording system. Once you record into the Radar 24, you may have to bump your tracks to another system for editing.


One of the Radar 24's weak spots is its inability to import or export its EDL/session data and to import or export audio files except WAV files from a 3.5-inch floppy disk. At 96 kHz, that gives you about seven and a half seconds of stereo audio per floppy.

The bottom line is that you can only transfer audio into and out of the Radar 24 in real time, as you would with an analog tape deck. However, iZ is working on adding audio-data transfer capabilities in the Broadcast Wave format and session-data transfer capabilities in the AES31 format. That will allow data interchange with other platforms during production and provide an alternate backup and archiving option using standard file formats.

Radar 24 Specifications

Tracks24Digital I/O(2)channels AES/EBU; (2) channels S/PDIF; (24) channels TDIFSampling Resolution (recording)16-bit or 24-bit linear (switchable)Internal Processing Resolution24-bitClock Reference Sourcesinternal crystal; external word clock; video; MTC; LTC; TDIF; AES/EBU; and S/PDIFTime Code Type and RateLTC/MTC: 24, 25, 29.97, 30 drop frame, 30 nondropDimensions4U × 10.75" (D)Weight43 lbs.

Another useful upgrade will be the activation of the Ethernet connection. That will let you integrate the Radar 24 into a networked environment.


Once you step outside the standard recording features, things get a little difficult. The Radar 24 requires a lot of button pushing to step through menus. If you miss a parameter in a menu, the documentation is not very helpful. The Radar 24 is supplied with a set of PDF files on a CD-ROM and a hard-copy Quick Start guide that is as much marketing hype as owner's manual.

Unfortunately, each chapter in the PDF manual is a separate file, and nothing ties them together — no hotlinks, bookmarks, or index. Some information, including important key shortcuts such as Jump to Session Start, cannot be found in any chapter. iZ reports that a new manual is in the works. Buy the hard-copy manual; on a number of occasions, the only reason I had my computer on was to look at the manual.


The Radar 24 is a superb recording system that combines the essential values of sonics and ergonomics with the priceless virtues of reliability and support. I was impressed with how well iZ “got it” about the real needs and priorities of recording engineers. When I spoke with iZ, my criticisms were almost always met with statements of steps already being taken to address the problems, and in many cases, the solution was already on the verge of release. Company representatives stressed their openness to feedback from users and cited numerous examples of newly released features that were given high priority because of emphatic user requests.

The Radar 24's weaknesses are primarily in its editing capabilities and its inability to exchange file and session data. With a strategic handful of GUI upgrades, iZ could forge an incredible synthesis of an optimized recording device with the generalized front end of a DAW. For the project studio, resolution of the noisy fan issue will also be important.

A realistic purchase of the Radar 24 would include several options, not the least of which is analog I/O. A realistic configuration would be the basic unit ($4,995), the Classic analog I/O card set ($1,695), and analog I/O cables (DB25 to XLR or TRS), which would cost about $750. The Radar 24 is best controlled using the Session Controller ($1,195) with a meter bridge (add $495 for the 24-channel version) and a 20-meter cable ($150). At that point, you're at more than $9,000, which is a bit more than a host-based DAW.

However, if you're interested in multitrack music recording, The Radar 24 is a tough system to beat. It sounds great, is easy to use, and is dependable. That's a potent combination. The Radar 24 is clearly capable of meeting the rigors of real-world professional recording.


iZ Technology
Radar 24
hard-disk recorder



PROS: Great sound. Multiple I/O options. Highly reliable. Strong support. Excellent tactile controller and operational feel while recording.

CONS: Lack of file exchange. Noisy fan. Poorly implemented GUI. Limited edit functions. Poor documentation.


iZ Technology
tel. (604) 430-5818
e-mail sales@izcorp.com
Web www.recordingtheworld.com