PURSUIT OF XLENCE

Akai MPC2000XL Percussion Sampler/Sequencer

Published in SOS December 1999
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Reviews : Sampling Workstation

Three years ago Paul Wiffen concluded that Akai had brought the concept of the sampling drum machine up to date with the MPC2000. Now he takes a look at its successor to see how much more you get when you buy XL.

Anyone who knows me will tell you I have always been a big bloke and, as the years march by, a constant diet of fine food and fine wine has only added to how I started out. As a result, whenever anybody buys me clothes or gives me promotional T-shirts at trade shows, they invariably settle on the XL size. Yet when I try on these XL shirts, I find they could often comfortably accommodate two people my size (if not three). Where are the massive people for whom these XL shirts are made (apart from in 'All-You-Can-Eat' American diners)? It seems that the jump between large and extra large in the minds of clothing manufacturers would be better expressed as 'big' and 'gargantuan'.

So does the same massive increase in capacity denoted by XL hold true in the world of sampling drum machines? Akai have just adopted this suffix for the new version of their MPC2000, a unit which I originally reviewed in SOS April 1997. Then, I decided that the MPC range had finally caught up with where other manufacturers had been when they went out of business 10 years before. This was thanks to the addition of looping and enveloping for percussion samples and tempo matching between loops. What new capabilities does the MPC2000XL boast to justify its gargantuan status? Or is it just a marketing ploy?

Well, the first addition is obvious enough with a single glance: the tilting LCD featured on earlier Akai units (but abandoned on the MPC2000) has returned, with three available positions. Although I did not particularly miss it on the 2000, I never tried to use that machine live. It is in the onstage environment, with lights and the resulting glare, that a feature like this proves its worth. Adjusting the tilt on the display is far easier than having to change the angle of the whole machine or, even worse, persuade the lighting guy to move one of his precious par-cans. As the relentless march towards totally computer-based systems in the studio and home continues, hardware manufacturers need to emphasise the better ergonomics of their alternatives, and that's obviously what Akai are doing here.

AKAI MPC2000XL £899 pros Time-stretch for the first time on drum machine/sequencer. Sound compatibility with all previous Akai samplers. Sequence compatibility with previous MPCs. Compatible with existing MPC2000 expansion boards. cons Sound Slicing long-winded, and does not generate associated sequences for triggering. Only two MIDI ports, with no expansion possible. Sampling only possible at 44.1kHz. summary The cheapest ever Akai sampling drum machine/sequencer still manages to expand memory locations and introduce unique features like high-quality time-stretching. Options can be used to add professional features such as separate outs, digital I/O and effects, but sadly not extra MIDI busses.

The new model has also undergone several expansions which fit the XL description perfectly. Sequence note capacity is trebled to 300,000 - again, something which is always welcome in a live situation. The fewer times in a set you need to resort to floppy or hard disk loads the better; however fast they maybe, there is always the potential for an error which leaves you having to repeat the operation. The maximum number of samples which can be held is doubled to 256, so you can not only keep more songs available without loading, but also more alternative percussion sets to go with them (provided of course that you have the necessary RAM available to hold them). Like the 2000 before it, the XL comes with 2Mb as standard, expandable to 32Mb via SIMMs (see the 'Sampling' box for more on this).

Another major benefit is that the operating system is now held in Flash ROM rather than on a floppy or hard disk, although it can of course be upgraded from floppy. This, at last, provides the best of both worlds; the permanence and reliability of a chip-stored operating system, combined with the ease of upgrade of a disk-based one. It is nice to see that hardware manufacturers are finally making use of features which increase the reliability of their systems over computer-based ones.

In terms of controls, there are now four individual Bank buttons, allowing you to switch straight between the 16 sounds assigned to the pads in Bank 1 and Bank 4 without having to cycle through them by constantly pressing a single Bank button, as on previous MPCs. There is also a Next Sequence key which allows you to set up what you want to play next, while the current sequence plays uninterrupted.

The Open Window key soon proves to be your salvation when doing any kind of editing. Having selected the main mode you want to work in using the Shift key and the principal task using the function keys just below the LCD, you cursor around the screen to the parameter you want to edit. However, the overall sample display or whatever other visual feedback you get may not provide enough resolution to see what you are doing. I soon learned to press the Open Window key whenever I felt like this: this gives you a much higher-resolution view of what you are working on (Sample End or Loop Start, for example).

Obviously, the fact that a £300 reduction in price has been achieved is quite impressive, particularly when hardware improvements like the tilting LCD have been added. Software expansion can often be added without extra cost (except for the man-hours involved in writing the stuff, which can be spread over all the machines made), but in the case of the MPC2000XL, I suspect there is also a faster processor - as we shall see in the case of some of the new software capabilities.

All the improvements mentioned so far, whilst they might make the machine more reliable, more user-friendly and more capacious, do not actually add to the suite of functions which it is capable of carrying out. However, I am happy to report that there are several additions to the functionality of the machine, and a couple of them are major ones, long overdue in my opinion. Three years ago, whilst praising the tempo-matching in the MPC2000 (achieved by tuning the sample up or down), I remarked on the lack of time-stretch in the machine. This was a particularly grave omission, since it is most often used on percussion loops, and by then it was a standard feature of all general-purpose samplers.

It Slices, It Dices     Like time-stretching, the other major addition to the software manipulation tools in the MPC2000XL has been available in computer software for some time. When you select Zone mode, you find an additional function amongst the available Edit options: Slice Sound. At first, I thought this might be a hardware-based equivalent of Steinberg's Recycle program, using attack transients to identify and isolate the separate percussion events in a loop and then trigger it at variable tempos without the need for repeated time-stretches. This, and the REX files that allow the results to be used quickly and easily inside VST, I regard as one of the few major advances in music technology to have been completely developed in the software sector. It would have been great to have the same facility in a stand-alone unit. Unfortunately, whilst Slice Sound makes a definite move in the direction of programs like Recycle, it doesn't quite make for the same labour-saving single-operation process which is a Recycled REX file. To begin with, the Zone mode allows you to divide a Sample into up to 16 equal parts. That's fine if you have drum loop which has been properly topped and tailed, which features a fairly regular rhythmic pulse on crotchets, quavers or semi-quavers, and which neither pushes nor drags the beat. However, those are by definition the loops which are easiest to recreate by sequencing and therefore the least desirable to process. Performing zoning on more interesting and eccentric loops leads to ticks at the end of some zones (as the first few milliseconds of the next transient are clipped off) and nothing of much interest in others except the super-quiet tails of the sound in the preceding zone. Fortunately, you are not stuck with the exactly even zones which Zone mode creates by default. You can go in and Edit the start and end points of each zone, just as if they were whole sounds in themselves. Although this is an awful lot of work, it does allow you to make sure that the zone divisions hit the attack transients of the individual events without clipping them, and shunt other zone start points to where something significant happens. In addition, moving the End point of one zone does move the start point of the next and vice versa (without which it would be a massive labour to move each start and end point individually). You will still find this a lengthy process, however. I found myself longing for the sort of automatic process in Recycle which uses a variable threshold sensitivity to pick out the individual transients. Once you have fine-tuned each zone start and end and had a cup of coffee to revive your flagging spirits, you can then use Slice Sound to make your single sample into the selected number of individual samples. Additionally, if you tick the Create New Program option, you will find the individual samples automatically laid out across the 16 drum pads (hence the maximum of 16 zones, presumably). Interesting results can then be obtained by triggering them in different orders, using the Note Repeat trigger function which has always been the MPC series' unique feature, or just using them as individual sounds in a new sequence. Sadly, there seems to be no way to go to the next stage of triggering them with exactly the timing of the original sample and varying the tempo, because as it stands the MPC2000XL cannot automatically create a sequence which triggers the individual samples in their original timings. For me, though, this would be the main reason why you might want to Slice a sound - to allow real-time variation of tempo during playback. This makes it quick and easy to match the loop with other material in your song if you don't know the tempos involved. Perhaps Akai plan to develop such a sequence generator in the future as a software update.

Well, now at last there is a percussion sampler which offers time-stretching, and Akai have clearly allowed the MPC2000XL to benefit from all the technology developed for their more general-purpose samplers. Not only are there three levels of quality to choose from (processing times are related to the quality achieved, so you can do a low-quality stretch to quickly check out if a loop works at the tempo of the target piece, and then do a higher-quality version once you are satisfied that it does), but 18 different algorithms are available to suit different types of material. These include not only those obviously developed for use with rhythmic samples (Hfreq Rhythm, Mfreq Rhythm, Lfreq Rhythm, Percussion and Lfreq Percussion) but also more general ones suitable for a fuller loops (Music 1, 2 & 3) and those even more specificially targeted at chunks of vocal (Fem Vox, Male Vox and Low Male Vox) or orchestral hits (Hfreq Orch, Lfreq Orch and Slow Orch). This means that those irritating lifts of vocals or symphonic stabs which have been the curse of popular music for the last 10 years can now at least be in time and tune (instead of one or the other, as is often the case).

In fact, when testing the time-stretching for the first time, I decided to go for the best quality (ie. the longest processing time) and was pleasantly surprised by how quick it was; a four-second sample was processed in less than 30 seconds. Now my surprise may just be an indication of how long it has been since I did a time-stretch on a hardware sampler (I have mainly been using computers for this recently), but clearly the processors used in hardware samplers have, like their more talked about personal-computer equivalents, got much faster. Indeed, it may well be that Akai chose not to include time-stretch on previous sampling drum machines simply because of the time it would have taken to process. If this is the case, then the faster speed of this processor is another clear improvement.

First of all, I decided to try speeding up a sample, as this is the more forgiving direction to go (the spaces in between the sounds get shorter, leaving the ear less time to notice problems). Getting to the time-stretch screen is a slightly lengthy procedure involving selecting Shift/Trim, then Edit, then scrolling through all the available functions, which include Discard (data before start and after end), Loop from Start to End (ie. loop the whole sound), Make Section a New Sound, Insert Sound into Current Section, Delete Section, Silence Section and Reverse Section. When you finally get to the time-stretch option, you have more choices to deal with; New Name (as a new sample is created), Ratio (the main parameter, setting the amount of change), Preset (the 18 algorithms listed earlier, each with its three different quality settings) and then the most neutrally named parameter, Adjust (more of this later).

I was just puzzling out exactly what percentage to enter in the Ratio field to achieve the degree of time-stretching I wanted, and wondering if I was going to have to get my calculator out, when I noticed the innocent-looking BPM parameter which had appeared above the F2 button. Pressing this opens the BPM Match screen, which is of course exactly what you need. The first parameter, Beat, allows you to set the number of beats in your source sample (you may want to go back and top-and-tail your sample properly, so that it is an exact number of bars/beats). If you enter this correctly, the MPC2000XL precisely calculates the value of the second parameter, Source Tempo, for you. Of course if you know the tempo already, you can simply enter it yourself. The final parameter on this screen is then of course the New Tempo which you want your loop to emerge at.

I started out giving a 120bpm Brazilian percussion loop a 20bpm increase - a fairly significant amount - using the Hfreq Rhythm algorithm at C quality (ie. the best). Despite the speed of execution which I remarked on earlier, the results were pretty reasonable, and certainly the equal of many more expensive samplers. At this point, however, I decided to go back and investigate the mysterious Adjust parameter. Examining the manual for some clue as to its function and range, I found that it allows you to 'tweak' the preset algorithm. Running from -50 to +50, a positive value increase the definition in high frequencies and percussive sounds, whilst a negative value helps smooth out bass sounds and sustained notes in the souce. I deduced from this that the positive value shortens the cycle length on which the stretching is based, whilst a negative value increases it. As the Brazilian percussion loop had lots of high frequencies and fast percussion content, I turned Adjust up to +50 and redid the +20bpm timestretch. The difference was quite remarkable, with a much tighter feel; compared with my first attempt, the difference was clearly audible. In comparison, the original I had done sounded like it had been put through a delay, or had twice as many percussionists, some of whom had been hitting the rum punch.

Sampling     As mentioned in the main text, the unexpanded MPC2000XL is supplied with 2Mb of RAM, expandable to 32Mb. The manual points out that, at a sampling rate of 44.1kHz, this gives you a total sampling time of 21.9 seconds in mono and 10.9 in stereo, while the fully expanded machine boasts 378.6 seconds in mono, 189.2 in stereo. If your're wondering how much extra time you can coax from the machine at lower sampling rates, however, you may be in for a shock, as the Akai can only sample at 44.1kHz - whether from analogue or digital sources. Nevertheless, once sampled, you can resample audio at lower rates, as explained elsewhere in this review - but in this day and age, it does seem a little antiquated that 48kHz audio from DATs will not be recognised unless it is first sample-rate converted.

In the other time-stretch experiments I conducted, I found almost invariably that whatever material I was using (from rhythm loops through vocals and orchestra hits to sustained string chords), and whatever algorithm I started with, the results could be audibly improved by tweaking the Adjust parameter. The only exceptions were mixed loops, which had high fast percussion content combined with low sustained notes; then the positive values improved the high fast stuff at the expensive of the low sustained content, whilst negative values did the opposite. This makes it clear that time-stretching complex material will always be a compromise, and that you are always better off time-stretching the components of your loop independently, if possible. If you can get your hi-hat component separate from your bass end and apply the appropriate algorithm to each, you will get the best results. However, if your chosen material is already 'pre-mixed', at least the Adjust parameter will let you mitigate the effects of the most suitable algorithm on the least compatible elements in the loop.

Other software developments include Slice Sound (see box on page 40) and the Resample option, added to the Convert functions, which allows you to digitally re-record samples at different sample rates (just as with the time-stretching, there are three different speeds of processing, giving different qualities of result). This allows you to save memory by reducing the sample rate and bit resolution. If you go far enough in this reduction, you can radically alter the character of sounds in the same way that early samplers did; often this can be a creative facility and not just a memory saver.

When I reviewed the MPC2000, it was already able to read sound data from previous MPC models such as the 3000 and 60 but not sequence data; this feature was planned as a future update. I am happy to report that the 2000XL comes with both sound and sequence data compatibility in place. Thanks to my friend James Asher who, you may remember, helped me out when testing the MPC2000 with his extensive library of MPC60 and 3000 sounds, I was able to try sound and sequence data together from the same floppy disk created on his MPC3000. We were not able to test the compatibility with data on hard disk or CD-ROM, as they have changed the type of SCSI connector on the XL to the smaller SCSI2 50-pin high-pitch variety, and we didn't have the appropriate cable, but as this side of the compatibility worked perfectly on the 2000 last time, I am sure that it is all still working fine. The same is true for sounds in S1000/3000 format.

The MPC2000XL also enjoys compatibility with all the optional expansion boards for the MPC2000. These are the EB16 effects board and the IBM208P separate eight output/SPDIF I/O board. This means you can put effects on the sounds in the XL internally or bring the sounds out separately for external EQing and effecting, and sample and output in the digital domain. The avantage of this backwards compatibility is that the optional boards are all already available (although I didn't get a chance to evaluate them).

Although the MPC2000XL is an evolutionary rather than a revolutionary product, building as it does on the capabilities of its MPC predecessors, it nevertheless adds unique capabilities like time-stretch and Sound Slicing to the MPC dynasty. Owners of large MIDI setups may find the dual MIDI Port limiting for extended sequencing, but for medium-sized studio and live setups the MPC2000XL makes an ideal centrepiece for those who eschew computers. The fact that several hardware and software refinements, like the tilting display and increased note and sound capacity, have been added at the same time as a £300 price drop is the icing on the cake.

information

MPC2000XL £899; EB16 effects board £299; IBM208P 8-output expansion board £249; ICM2T3 SMPTE chip £tba; SMX008 8Mb Flash RAM board £249; MPC-CD additional sample CD £49. Prices include VAT. Akai UK +44 (0)20 8897 6388. +44 (0)20 8759 8268. www.akai.com/akaipro/index.html