A versatile one-stop CD-mastering machine.
If you had walked into your local music emporium two years ago and said you wanted a single unit that comprised a 24-bit hard-disk recorder with five hours of storage, basic premastering software, CD extraction, and a CD recorder with digital I/O for less than $2,000, they would have laughed you right out of the place. And if you had demanded 24-bit CD backup capabilities in the bargain, the men in the white coats would probably have arrived before you even got to the parking lot.
As happens so often in this age of the faster, cheaper, and smaller, yesterday's crazy dream is today's Alesis Masterlink ML-9600. The 2U rack-mount machine works similarly to a modular hard disk recorder in that it records audio files on a hard drive and allows you to apply DSP and organize tracks into multiple playlists for sequencing and downloading. You can even use files recorded at different sampling frequencies and bit rates in the same playlist, which can come in very handy. The internal 4.3 GB IDE holds over 5 hours and 10 minutes of 16-bit, 44.1 kHz stereo files or 95 minutes of 24-bit, 96 kHz files.
In addition to its main features, which I'll detail as we go along, the Masterlink has a secret weapon to increase its odds in battle: the ability to write 24-bit AIFF files to CD, using the ISO-9660 CD-ROM format. This means it is possible to store 24/96 audio on standard CD-Rs; transfer these files to Windows, Mac, or Unix systems; and use the same CDs for backup or audio playback. Of course, the 24-bit CDs only play back on the Masterlink, since no other CD recorder or player supports this format. The machine also plays 16-bit CDs, but you have the added benefit of 24-bit 1285 oversampling DACs.
GAZINTAS AND GAZOUTASAll controls are located on the front panel, including standard CD functions, a power switch, various status indicator lights, rows of programming buttons, and a rectangular 1.75-inch- by-6-inch display. The internal hard drive is quieter than most hard drives I've encountered, a real plus for single-room studios. A headphone jack with a volume control is another bonus.
The rear panel (see Fig. 1) sports analog line-level inputs and outputs on RCA (-10 dBV) and XLR (+4 dBu) connectors. You also get stereo AES/EBU digital I/O on XLRs and stereo S/PDIF digital I/O on RCAs.
GETTING STARTEDAfter I perused the 42-page manual, it took only 15 minutes to unpack the carton, hook up the unit, navigate through a few windows, and press the Record button. Very impressive indeed! Alesis has packaged one blank CD-R, rack ears, and a remote control with the unit, so if you have cables, a monitoring system or headphones, and two AA batteries for the remote, you're set to go right out of the box.
For testing purposes, I followed the progress of a single song from mixdown to a finished master. I chose a big production number I've been working on at Guerrilla Recording for an upcoming release by Bay Area songwriter Mark Growden. The song, entitled "Devouring Time," is a dense concoction of martial drums, blaring trumpets, booming bass drum, crashing cymbals, gongs, and more. In short, it's a daunting challenge for any A/D converter or mastering system. Working directly from the analog multitrack master tape, I assembled a mix and prepared for my first test, a comparison of audio quality between the original master and the Masterlink at various bit rates and sampling frequencies.
For the initial round of comparisons, I mixed 16-bit, 48 kHz audio to DAT, using an Apogee PSX-100 for clocking and A/D conversion. I tested the Masterlink with its onboard converters set at 16-bit, 48 kHz analog in and at 24-bit, 96 kHz analog in. I also used the Apogee PSX-100 for clocking and A/D conversion set at 24-bit, 48 kHz. (The PSX-100 will not support the Masterlink's 88.2 or 96 kHz sampling rates.)
LIVE OR MASTERLINK?After I conducted a brief blind listening test, subtle differences emerged between 16-bit sound using the Masterlink's self-clocked analog input and using the digital input, which the PSX-100 clocked and converted. When I toggled the Masterlink input to analog in, the prominent bass drum in my mix diminished in size and impact, snare drum rolls and other transient details vanished into the background, and overall high-end clarity suffered.
It is important to point out that the Apogee PSX-100 - a mastering-quality ADC/DAC with a low-jitter clock - is a converter only and retails for twice the cost of the ML-9600. The use of a dedicated outboard converter like the Apogee has become standard practice in many studios as a way to bring out the best in any digital storage format. Such a device can have a profound impact on overall sonic quality, yielding 16-bit results equal to or better than higher-resolution bit rate storage accomplished with average converters.
Not surprisingly, I found that I got the best fidelity, compared to the analog multitrack master, using the Apogee PSX-100 as the master clock and converter, set at 24 bits, 48 kHz.
On playback, I noted an added hardness in the high end, as well as a diminution of reverb tails, which I attributed to the Masterlink's DAC section. A direct comparison of 24-bit, 48 kHz output through the Apogee's and ML-9600's converters confirmed this observation: I experienced an attenuation of low bass, scratchier highs, and a flattening of depth and dimension across the entire Masterlink mix.
To put this in perspective, the ML-9600 converters are audibly superior when compared with a midprice CD player. In further testing, the Masterlink's analog outputs also offered better resolution and depth than the converters in my studio DAT machine, although I preferred the timbre of the DAT, which had fuller lows and a smoother high end on an identical 16/48 mix.
The Masterlink's self-clocked 24/96 mix was a close second, exhibiting reasonable fidelity to the original master. The decrease in reverb and room sound was significant, as was a lessening of the bass drum's fundamental punch. This loss of detail, though subtle to most ears, is typical of the level of differences one observes when comparing standard DAT or CD recordings to a half-track, analog mix. When auditioning the 16/48 Masterlink mix, I noted additional harshness in the high end, even with the Apogee converter in the chain. Using the ML-9600 analog in (and internal clock) further collapsed the soundstage, diminished lows, and yielded the transient muffling noted earlier.
IN THE MACHINEOnce I had my mixes on the Masterlink's hard drive, I set out to explore the unit's processing options. Cropping (trimming sounds or silence from the beginning and the end of a track) is the only destructive editing feature onboard. This operation, like the related fade-in/fade-out function, is straightforward, taking less than a minute to audition, adjust, and double check. The remote control offers a single button that makes cropping a snap, and I was pleased to find I could even adjust cropping while I was in an active DSP window.
There are no options for sample-accurate waveform editing, crossfades, random access, or markers within a track. Because the Masterlink lacks a shuttle wheel, you must do all scrolling within a track with the CD Scan (double-arrow) button, which took about 15 seconds to zip to the end of my 3-minute mix. A handy Track End feature instantly accesses the end of a long track and allows scrolling backward from that point.
In routing order, the DSP processing blocks in the Masterlink are track gain, compression, parametric EQ, limiting, fades, and normalizing. The manual explains all of these steps adequately but gives no warning for novice users about the potential hazards of applying multiple gain boosts through this chain. Inexperienced recordists may have to find out the hard way that you can't raise a track's gain, then add a ton of low-end shelving EQ, and finally pile on the limiting, without getting some overload distortion.
The well-equipped single-band compressor section allows peak or RMS detection; left, right, or summed channel keying; and multiple metering options. You get four soft-knee settings in addition to conventional threshold, ratio, hard-knee, attack, release, and makeup-gain settings. In practice, I found it difficult to get the compressor to function transparently without clamping down too much on the dynamics, even at minimal settings. But under average conditions, I heard no pumping or generation of unpleasant artifacts.
The controls for the three fully parametric EQ bands are effective, and it's easy to hear what you're doing. The sound of the EQ, though not particularly sweet in the high end, is acceptable. You can configure the high and low bands as shelving filters, and I was impressed to find that I could actually dial in heavy-handed amounts of low and high shelving on a 16-bit file without audible peak distortion.
The most tantalizing DSP function for mastering is the look-ahead peak limiter, a 3-stage level maximizer that combines limiting and automatic normalizing with an adjustable final output level. If you work in the compression-crazed environment of today's pop, alternative, and hip-hop music, you'll find plenty of uses (and abuses) for this program. The limiter works as expected, though during a unity-gain test at moderate levels (-4 dB threshold and output gain), I observed that it added some harshness to the high end of the trumpets and cymbals in the 24/96 mix.
A fourth normalizing DSP block automatically adjusts the overall track gain so that the highest peak reaches 0 dBFS. Since the unit provides a limiter, this block seems largely redundant. Because the upward scroll button and the Yes button are one and the same, it's easy to scroll through this feature too quickly and engage the Yes/No normalizing command by accident. But it took just a few moments to normalize my 3-minute song, and you can bypass the effect. In fact, an on/off bypass option is always available for the compression, EQ, limiting, and normalizing sections while the user is in the active DSP screen.
BURNING AMBITIONAt last, it was time to burn a CD. Following the step-by-step instructions in the manual, I hit a snag when I created a new playlist to resequence my CD program and then couldn't figure out how to move my preexisting audio files into it. The manual directed me to the wrong page number, and bumbling through various windows and button options proved fruitless. After careful reexamination of the 11-page playlist section, I finally found the answer I was after. The procedure, which involves lots of button pushing combined with scrolling through all the audio tracks, is strikingly counterintuitive and hard to remember, especially compared to the ease of operation I had experienced with the Masterlink thus far.
In addition, I discovered that the new playlist didn't reflect the nondestructive DSP changes I had made to my original tracks. There are positive and negative aspects to this design. Of course, re-creating or writing down and reapplying previous settings entails extra work. (According to Alesis, the upcoming version 2 firmware facilitates copying and pasting.) On the other hand, this makes it easy to devise and audition a variety of mastering processes on multiple clones of a mix while leaving the original audio file untouched.
However, unlike computer-based editing, Masterlink editing does not allow you to rename tracks so you can identify different versions of the same audio file when burning a 16-bit CD. So keep an old-fashioned notebook handy if you plan on getting clever with this sort of compound processing.
The Masterlink's 45 CD recorder took 20 minutes to burn a 17.5-minute program to a 16-bit, 44.1 kHz Red Book CD (including applying DSP, bit-rate reduction, and sample-rate conversion from 16/48 and 24/96 files). Tracks butted together seamlessly as intended, and sample-rate conversion quality was good.
The 24-bit CD had two 3-minute mixes on it and took 11 minutes to complete with no DSP. According to the manual, a standard 650 MB CD-R holds a maximum of 19 minutes of 24/96 data and takes 36 minutes to burn. This means a backup of a full-length project will require at least three CD-Rs and 2 hours to complete. That's life in the high-resolution lane!
Alesis's CD24 format also displays track titles during playback on the Masterlink, a nifty feature. The new version 2 firmware allegedly will allow saving playlists to disc in the CD24 format and will add new options for looping, splitting tracks into two parts, copying audio files and DSP settings, and adding start and end access time offsets.
ROOM FOR IMPROVEMENTAfter learning how to navigate the playlist assignments and name tracks, I found basic recording on the Masterlink generally quick and easy, as was maneuvering through screens and parameters. But the main 4-button array, where you do most of the scrolling and entering, seemed unnecessarily small and unergonomic. And it didn't take long for this grizzled computer-editing veteran to get frustrated with the necessity of alphanumeric scrolling, the absence of a shuttle wheel, and the limitations of a diminutive window interface. Mounting the device at eye level or in a sloping rack will greatly help you avoid fatigue.
Alesis obviously had to indulge in some cost-cutting measures to hit this low price point. The implementation of dual digital and analog inputs without any selector switching isn't just cheap, it's careless, and it is sure to cause customers some grief. The lack of a shuttle wheel is a painful oversight, as is the inability to adjust analog input gain in Record-Ready mode.
Considering that many novices will use the ML-9600, Alesis should put more emphasis on tutoring its customers about DSP decisions that will permanently affect their masters. The manual's inadequate coverage of vital topics such as gain staging, dithering, and digital-versus-analog input clocking does users a disservice, perpetuating the myth that you can manipulate and bounce around digital audio indefinitely without degradation.
In addition, the Alesis converters, though superior to those in DAT and CD players I tested, still couldn't quite capture all the intricacies of a complex analog master. Pairing the unit with an Apogee PSX-100 helped, but I had higher sonic expectations of a 24/96 stand-alone recorder. I'm not getting rid of my "infinite-bit" analog mixdown deck just yet!
FINAL THOUGHTSThe Masterlink delivers professional-sounding results, and I would expect it to appeal to a wide cross section of the audio world. Studios that already have computer-editing and CD-burning capabilities would be well advised to get hip to the Masterlink's potential for high bit-rate storage, 24-bit in-house reference copies, and premastering, especially when combined with an outboard A/D converter. And there's no question that the ML-9600 is a godsend for semipro studio owners and enterprising musicians who just want to produce competitive-sounding demos on a budget, without investing in racks of expensive gear.
This little unit packs a huge punch by offering beginning recordists enough hard drive space for several CDs, plenty of processing power, a logical interface, and elementary premastering tools, all in a very affordable package.