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HIGHLY RATED?

MOTU 1296 High-Sample-Rate Audio Interface By Robin Bigwood
Published June 2001

HIGHLY RATED?

MOTU's good‑sounding, competitively priced audio hardware has won them a lot of friends in the project‑studio and professional arenas. The latest addition to their range is a 12‑channel interface that offers 96kHz, 24‑bit recording. Robin Bigwood tests the 1296.

The 1296 is the latest in MOTU's line of audio interfaces based around their PCI324 PCI card, and the first to offer 88.2 and 96kHz sampling rates in addition to the more familiar 44.1 and 48kHz. In contrast to the other audio interfaces in the range, it has relatively few frills — there's no headphone output, no front‑panel controls, and no stand‑alone routing or sample‑rate conversion facilities. As such, the 1296 is something of a specialist product, and one that will very often, I imagine, be bought to supplement an existing 2408 or 1224 interface. It's certainly a no‑nonsense bit of kit, aimed at the upper end of the project‑studio market, and it does what it does with few compromises and a refreshing simplicity.

Essentially, the 1296 offers 12 +4dB analogue inputs and outputs on XLRs, with high‑quality 24‑bit converters that MOTU claim are capable of delivering a 117dB (A‑weighted) dynamic range. In addition, an AES‑EBU digital input and output (on XLRs) is equipped with independent sample‑rate converters and its own timing clock, allowing it to operate entirely separately from the analogue section. There's also a word clock input and output, and a separate AES digital word input. For those involved in surround‑sound mixing, the 12‑channel 1296 can, of course, handle two simultaneous 5.1 mixes.

The Unit

MOTU's Setup Wizard is designed to help you get your chosen interface up and running quickly.MOTU's Setup Wizard is designed to help you get your chosen interface up and running quickly.

The 1296 comes as either a 'core' system, together with a PCI324 card, or as an expansion unit for users who already have the PCI324. The PCI324 is a half‑length PCI card, and I can't imagine anyone would experience problems fitting it, especially given the detailed instructions in the manual. MOTU says it's based around a custom VLSI chip which is capable of handling 72 simultaneous inputs and outputs (that's 144 in total!) at 44.1 or 48kHz. At the higher sample rates 36 simultaneous inputs and outputs can be used at one time, so it's theoretically possible to connect three 1296s to a single PCI324, or to use a single 1296 in conjunction with, say, a couple of 2408 MkII interfaces.

Communication between the 1296 and the PCI324 is via MOTU's proprietary AudioWire protocol, using a standard IEEE1394 FireWire cable. There are three AudioWire sockets on the PCI324's connector panel, as well as a standard nine‑pin ADAT Sync connector for sample‑accurate transfers with ADAT recorders, and an eight‑pin RS422 'Control Track' socket for attaching a MOTU Digital Timepiece synchroniser. Amongst other things this facilitates sample‑accurate transfers with Tascam DA‑series multitracks, and allows the PCI324's timing clock to resolve to externally supplied SMPTE timecode.

The 1296 itself is a 2U rackmount unit with an elegant and uncluttered front panel consisting of two banks of 12 LED level meters, a smaller section to the left displaying clock and sample‑rate information and, on the far right, a rocker‑type power switch. It's noticeable, both on the 1296 and on the new Firewire‑based 828 interface, that MOTU seem to have dropped their silhouetted unicorn logo. This is much lamented amongst MOTU diehards, but shouldn't adversely affect other users too much!

The 1296's metering is very nice indeed, with each of the 12 inputs and outputs getting its own 19‑segment stack of LEDs, calibrated in 3dB steps from ‑42 to ‑6dB and in single‑decibel steps from ‑5 to ‑1dB. There are two 'over' LEDs, one which lights only momentarily, and one which latches on when the signal reaches full scale even for a single sample. Settings for peak hold and 'over' hold time are made from within the PCI324 console software (of which more later).

The small sample‑rate information section on the front panel, labelled 'Clock', presents its information in a very clear and unambiguous way, with separate indicators for the sample rates in use for the A‑D and D‑A converters, and the AES‑EBU digital section. Again, settings can only be changed from within the PCI324 console application.

Around the back of the 1296 is where it's all happening. Dominating the rear panel are 12 analogue inputs on female XLR connectors and, below them, 12 outputs on male XLRs. To the right of these are the AES‑EBU digital connectors, on a further pair of XLRs, one male and one female. Below them a pair of BNC connectors handles 'System Word' in and out, and close by there's the separate 'AES Word In' BNC. At the extreme lower left there's a standard IEC three‑pin power inlet, and at the other end, an IEEE1394 AudioWire socket. Everything is clearly marked and all the XLR sockets have strong metal retaining clips. The 1296 does have a fan, which vents on its right‑hand side, but it's quite quiet in operation — in fact, I only noticed it after a couple of days of use.

The 1296 I received for review came as a core system, so as well as the 1296 interface itself the box contained a bubble‑wrapped PCI324 card, a 15‑foot AudioWire cable, a power lead, and a bundle of documentation. There's a dual‑purpose Windows/Mac manual, a manual for AudioDesk (a bundled multitrack audio recorder and editor for Mac), a cross‑platform installer CD, and the obligatory product registration card.

MOTU specifies minimum computer requirements of a 200MHz Pentium processor with at least 32Mb RAM running Windows 95 or 98, or for Mac, a 200MHz 604e with at least 32Mb RAM and OS 7.6.1. I imagine these are absolute minimum requirements, though, and to get the best out of the 1296 you should really try to partner it with something much more powerful and up‑to‑date. It worked a treat on my 350MHz blue and white G3, with 256Mb RAM. It goes without saying that you also need a free PCI slot in your computer, and a decent size high‑spec SCSI or IDE hard drive, preferably one dedicated to audio storage.

Setting Up

Non‑Digital Performer users will need to use MOTU's console application to control the 1296.Non‑Digital Performer users will need to use MOTU's console application to control the 1296.

With the PCI324 card in your computer and the 1296 connected to it, you then need to install drivers and accompanying software from the provided CD. There are ASIO drivers for Mac and PC, a PC Wave driver, and a direct PCI324 driver for Macs running MOTU software. It was here that I ran into a problem, though. The 1296 ships with AudioDesk multitrack recording and editing software for Mac, which is like a MIDI‑less version of Digital Performer. I had no need for this because I already have Digital Performer, but there was no way to install the essential PCI324 software without getting AudioDesk along with it. It was particularly annoying to find that the AudioDesk installation had written lots of extra plug‑ins into the MOTU folder in my Extensions folder. These plug‑ins, whilst perfectly usable, are older versions of the ones that come with Digital Performer, and I can only hope that, had I not previously arranged my existing DP plug‑ins into subfolders, the AudioDesk installer wouldn't have trashed them, necessitating a reinstallation of Digital Performer. MOTU really ought to provide an option to not install AudioDesk for existing users of their software.

MOTU make quite a noise about how easy it is to get up and running with the PCI324 and 1296 once the drivers are installed, and to this end provide a Setup Wizard for Windows and Mac which promises to painlessly set up the PCI324 console ready for use with your audio software of choice. For those unfamiliar with the concept of configuring and using audio interfaces the Setup Wizard can only be a good thing, but whilst using it I experienced another glitch. The Wizard correctly identified the connected 1296 at the beginning of the configuration process, but by the end it had mysteriously changed its wizardly mind, and suggested I'd connected a MOTU 24i instead. Even when I'd managed to overrule this the PCI324 console ended up being configured incorrectly, and I had to manually enable the 1296's single analogue I/O bank.

Worse still, I tried installing the PCI324 in a 400MHz G4 (running System 8.6) and the wizard couldn't recognize what interface was connected to the PCI324, although it did know that something was connected. In fact, it was impossible to use the 1296 until I'd located a newer version of the PCI324 driver on my Digital Performer installer CD, at which point everything ran flawlessly.

Software

CueMix provides a simple virtual mixer, allowing you to set up your monitor routing appropriately.CueMix provides a simple virtual mixer, allowing you to set up your monitor routing appropriately.

The PCI324 console is really provided for Windows users, and for Mac owners not running MOTU software, as it's effectively built into AudioDesk and Digital Performer. Every aspect of the PCI324 card and the 1296 is controllable from it, as are the functions of any two additional MOTU interfaces connected to the PCI324 card. Several levels of complexity on offer, from simple enabling/disabling of banks of inputs and outputs, through to complex routing and pseudo‑patchbay options.

The upper part of the PCI324 console window controls parameters related not to the 1296 but to the PCI324 card itself. They include system Sample Rate, Clock Source and Monitor Outputs selection, although perhaps the most crucial is the Samples Per Buffer pop‑up menu, which effectively controls the monitoring latency of the PCI324/1296 system. Smaller buffer sizes mean lower latency but higher processor load, and whilst usable settings may be found, much lower latencies can be achieved by using the CueMix console software.

The role of CueMix, whose user interface looks a little like a very simple mixing desk, is to directly patch selected 1296 inputs to the monitor outputs, taking the relatively short trip to the PCI324 card and back. Without CueMix your audio input passes through the PCI324, its software driver, the computer's processor and your host application, before going back out the same way to the 1296's monitor outputs, with increased latency the inevitable result. The downside of using CueMix, of course, is that you won't be able to process your input with any of your host application's plug‑in effects, but at least it gives you the option to choose between very low latency or using the effects architecture of your software. Digital Performer and AudioDesk users don't need to use CueMix at all, as all its functions are taken care of by the Input Monitoring Mode dialogue box in conjunction with the input and output routing currently in use.

Digital Connections

'Zero'‑latency monitoring is available to users of the 1296, but you have the option to route inputs through your audio application instead so that you can hear them with effects, if necessary.'Zero'‑latency monitoring is available to users of the 1296, but you have the option to route inputs through your audio application instead so that you can hear them with effects, if necessary.

An important aspect of the 1296 is its AES‑EBU digital input and ouput, which, like the rest of the interface, are 24‑bit 96kHz capable. There are independent sample‑rate converters on both input and output, and in addition, the 1296's digital section has its own clock source which can operate completely independently of the analogue section. The digital input and output are configured in the PCI324 console, under the 1296's 'Interface Options'. Setting them up is pretty straightforward, and any rate conversion that comes into play is indicated on the 1296's front panel, as is the presence of an external timing clock for the the digital output. When active, the digital input does, however, 'steal' two of the 1296's analogue inputs (also selectable in the 'Interface Options'). Because I'm not exactly falling over equipment with AES‑EBU digital connections in my studio, I used an M Audio CO3 S/PDIF to AES‑EBU converter to connect a range of external equipment with both co‑axial and optical digital outputs, and it fulfilled its role admirably.

Given that the 1296's sample‑rate conversion occurs in real time, it's amazingly good, and I found it hard to distinguish between original and converted signals when, for example a 44.1kHz output from a CD player was brought into Digital Performer at 48kHz. Conversion of 44.1kHz signals to higher sampling rates worked equally well, as did the conversion of a 48kHz DAT recording down to 44.1 kHz. High frequencies remained clear and well defined, and stereo image hardly suffered at all. Very impressive.

Sound Quality

The 1296 provides a single stereo AES‑EBU‑format digital input and output. Using the digital input means that you lose a pair of analogue inputs.The 1296 provides a single stereo AES‑EBU‑format digital input and output. Using the digital input means that you lose a pair of analogue inputs.

Ultimately, the raison d'etre for the 1296, aside from the claimed high quality of its A‑D converters, is its ability to record at 88.2 and 96kHz sampling rates, and I was keen to make some recordings at a variety of sampling rates and bit depths and compare the results. Supporters of high‑sample‑rate recording argue that higher frequencies can be recorded more accurately, without the inherent quantisation errors that occur with 44.1 and 48kHz systems. A higher sample rate, they say, also places any undesirable effects of anti‑aliasing filters in use at the A‑D conversion stage well outside of the human hearing range. The trade‑off, however, comes in the form of increased data storage requirements — a 24‑bit 96kHz recording takes up about three times the disk space of one made at 16 bits and 44.1kHz — and greater processor demands.

There are those, of course, who argue that any perceived advantages of higher sample rates are purely imaginary. A more pragmatic but equally valid line is that the majority of the music‑consuming public don't have access to replay systems that could reveal the differences anyway, and that most wouldn't hear or care about the differences even if they did.

Technical, musical and social arguments aside, digital recording theory suggests that it's high frequencies in particular that should benefit from a higher sampling rate, so I started off by recording a very lively‑sounding reproduction harpsichord with the 1296 configured for 96kHz 24‑bit operation. I then immediately made a recording at 48kHz 24‑bit so I could compare the two side‑by‑side. I used a variety of microphones to make the recordings, including Rode NT1s, an Audio Technica AT4033 and Sennheiser MKH20 omnis, all running through Mackie VLZ preamps. Monitoring was via Alesis M1As patched directly to two of the 1296's outputs.

The 96kHz take sounded every bit as good as I'd expected — a big, confident, colourful sound, with excellent stereo imaging, superb detail, and a tangible sense of involvement. I then switched sampling rate and listened to the recording made at 48kHz. To say the difference was subtle would be an understatement, but there certainly was one, although it's hard to define or describe without seeming to exaggerate the issue. Of the two the 48kHz recording sounded very slightly fuller and more rounded, albeit with a hint of constriction at the top end. The 96kHz recording was more 'airy', maybe, but it also sounded leaner and somewhat more clinical.

I then moved on to record acoustic piano in a pretty lively, resonant room. The sampling rates were 44.1 and 88.2kHz, and this time there was a more marked difference, with the 88.2 recording providing a greater sense of depth and space. The 44.1 take was again more rounded, although rather less 'roomy'. Interestingly, though, I'd find it hard to say which of these recordings I'd prefer to listen to — both were extremely good in their own right.

To put things in a slightly different perspective I then made recordings of a number of instruments, including recorders, concertina, percussion and voice, using first the 1296 then my 2408 MkII (running at the same sample rates). I'm a big fan of the 2408, but I'll readily admit that, without exception, the 1296 sounded sweeter, clearer, and had better focus. In fact, the difference between the 1296 and 2408 was much more pronounced than anything I heard when comparing recordings made using different sample rates on the 1296 alone, which tended to confirm my suspicions about the claims made for high‑sample‑rate recording — whilst differences are audible with extremely critical listening, it's always other aspects of the signal chain that have a greater impact. I can understand that sample rates of 88.2 and 96kHz (and even 192kHz and higher) appeal to purists of the recording world, but I personally find it harder to see how they really benefit the vast majority of music consumers, either at home, in the car, or in the cinema. I would be very interested, though, to hear a large scale orchestral work recorded at 96kHz and with 24‑bit resolution, as there is much to suggest that any benefits gained from using high sample rates become more pronounced in line with the complexity of the recorded material.

Conclusion

I would certainly agree with the often‑heard statement that high‑sample‑rate recording is something you take seriously only when the rest of your signal chain and recording process is beyond reproach. But that's not to say that what the 1296 offers is superfluous or excessive — far from it. Its A‑D conversion is excellent, and I personally would be tempted to invest in one for this aspect of its performance alone, using the higher sample rates for projects and clients that demanded them. The digital sample‑rate conversion is good, too, and for a working studio, having to quickly deal with material at a range of rates and formats, could be worth its weight in gold.

As far as the competition goes, the much cheaper M Audio Delta 1010 is renowned for its sound quality, but has no metering or sample‑rate conversion facilities. The FireWire‑based Metric Halo Mobile I/O 2882 has onboard mic preamps and phantom power and is capable of 96kHz 24‑bit recording, but has only eight channels of input and output, while the Crest FB88 has a similar specification without the preamps.

What none of these alternatives offer is the ability to be mixed and matched with other interfaces, as is the case with the 1296 and other interfaces in the MOTU range. This counts for a lot, as it means you can add 96kHz capability to, say, an existing ADAT‑ or Tascam‑based digital system with ease. The build quality of the 1296 is excellent, the software and drivers are well written and dependable, and the front‑panel metering is clear, informative and accurate. And given that the 1296 is a fine‑sounding 12‑channel system, it represents excellent value for money. It's going to be hard to give it back.

Latency

Whilst the 1296 doesn't achieve the holy grail that is zero latency, it does get pretty close. With a Samples Per Buffer setting of 512 I was able to achieve a virtually unnoticeable latency of around 5mS using CueMix, and a slightly sluggish but quite workable 25mS going through effects in Digital Performer. I did notice a few clicks and pops using lower Samples Per Buffer settings, though they occurred only whilst monitoring during recording, and never on playback. The bottom line is that, for the majority of people, latency will be unlikely to be a major problem whilst using the 1296.

Can Your Computer Keep Up?

Just because MOTU's AudioWire can handle lots of simultaneous inputs and outputs it doesn't mean that your computer can too. For the hell of it I record‑enabled all 12 channels on the 1296, and a further 24 channels on a 2408 MkII. Sample rate was 48kHz and resolution 24 bits. My G3 did manage to record — for about 10 seconds, after which a processor spike crashed Digital Performer. From what I could observe, though, the demands made of my audio drive, a 45Gb 7,200rpm Maxtor IDE internal, were not unduly large, so it seems that processor power is an important factor in handling large numbers of inputs and outputs. I was not able to ascertain what sort of system would need to be used to handle 72 simultaneous channels of 96kHz 24‑bit audio.

Pros

  • Fantastic‑sounding A‑D converters.
  • ccurate, clear metering.
  • Real‑time sample‑rate conversion.
  • Expandability.

Cons

  • Annoying software installer!

Summary

The 1296 most obviously appeals to those looking for a high‑sample‑rate interface, but great‑sounding converters and crystal‑clear metering should ensure a wider following.