Passport Audio Trax
Apple Macintosh Software
As the Apple Mac computer falls in price, attention is being focussed on less expensive software - like Audio Trax. Ian Waugh checks out a sequencer / audio recorder which won't break the bank.
The integration of sequencing and audio recording looks set to change computer-based recording - and we're not only talking about professional, mega-buck systems.
Billed as the cheapest ever direct-to-disk recording system, Audio Trax - a snip at £199 (RRP) - had to warrant closer examination from MT. To preempt your glance at the verdict, let's just say now that it works, it works well, but it has some limitations. Well, of course it would for that price, wouldn't it?
Essentially, this Mac sequencer/recorder is based on Passport's Trax (ST version reviewed MT, December '90) sequencer, to which has been added two audio tracks. Passport's Master Tracks Pro (ST version reviewed MT, September '90) of which Trax is a junior version, is well regarded in the biz, being a powerful and easy-to-use piece of software. One of its pioneering additions to sequencer layout is the Song Editor, which shows the music in bar increments - bar as in musical measure, not one of the lines on a grid in a piano roll editor - which makes block editing a pretty straightforward business.
Although both previous reviews have concentrated on the ST versions, these are operationally similar to the Mac version, so the finer details of the sequencer will be omitted here.
Let's start at the beginning - system requirements. Audio Trax (review v1.01) requires an SE/30, LC, IIsi or one of the more powerful Macs. It will run on a Classic II but, apparently, only allow you to record one audio track. You also need at least 4Mb of RAM and System v6.0.7 or higher. It is System 7 compatible, which is good news.
You need a hard disk, of course, although it would be a brave man or woman indeed who tried to use a Mac without one in any case. It uses disk space at the rate of more than 1Mb per minute, per channel at 22kHz. According to the manual, the audio section of a five-minute song would require 12Mb of disk space. You can record at 11kHz and double the megabyte/minute capacity but that's really lo-fi and for voice comments only, I'd suggest.
You also need a MIDI interface (if you want to record MIDI data), plus a sound input device. The LC and IIsi have one built in. Other Mac owners can use MacRecorder (extra, of course) although this can only record at the 22kHz sample rate (Audio Trax' manual hinted that an update may be possible).
Audio Trax disables the Mac's internally-generated "beep", so you should select another warning sound from the Sound section of the Control Panel (I hated the beep, anyway).
The software isn't protected (Passport are rapidly running the risk of being voted my number one user-friendly software house). It uses Apple's MIDI Manager (supplied) which you drop into your System folder. The Manager was designed to allow multitasking MIDI and a cute, hi-tech patchbay lets you route MIDI software to the Mac's MIDI interface and other MIDI Manager compatible programs.
The sequencer itself is very easy to use. The only slightly disconcerting aspect is that you must open a file onto disk before you can use it, even just the MIDI sequencer section, so if you want to just boot up, mess about and switch off, remember to erase aberrant files.
Operation revolves around windows, of which there are five - Transport (contains the tape controls), Conductor (sets the tempo), the Track Sheet (lists the tracks), the Song Editor (already mentioned) and the Step Editor (our friend the piano roll editor).
Audio Trax has 64 MIDI tracks with check mark boxes for play, record, solo and MIDI channel. They also have a loop box and a volume slider which is extremely useful.
You can name the tracks and select instruments for them from an Instrument Field menu. This contains a list of 11 devices including the MT32, D110, U220, Kurzweil K1000, Kawai K1 and a GS device. Each contains a list of the instruments' presets so you can select sounds by name.
"Audio Trax has the ability to cut and paste the audio to produce some interesting vocal effects which would be impossible using tape."
Sounds can be auditioned on the fly using this method of selection. It's a brilliant idea but you can't edit the device list or read user-programmed sounds into it. There are a couple of generic non-named devices, however.
The Song Editor is useful for both copying and reordering song sections (although upbeats can confuse the issue). The Step Editor is the most complex of the editors (and warrants 23 pages in the manual) but it's still fairly easy to use. You can zoom in and out; set markers; cut, copy and paste, and drag the notes around as you would expect in such an editor. It's also used for step-time note entry (where did you think its name came from?). It adopts one of the more sensible and friendly approaches to step-time entry. You select a duration from a list of note icons and click the required pitch onto the score. Alternatively, you can select a duration and play the note in from a MIDI keyboard - the method I prefer.
The two audio tracks sit above the MIDI tracks in the Track Sheet and have the same options as sequencer tracks, except that they can't be looped and clicking on the instrument box calls up an Audio Set Up box instead of a device list. Here you can select the 22kHz or 11kHz sampling rate and the bar, beat and clock on the audio tracks from which recording will begin. An "LED" ladder indicates the volume of incoming audio signals.
The input is quite sensitive using the IIsi's own mic, and the input level indicator responded to quite distant extraneous sounds. An optimum recording level was quite difficult to achieve, especially for sounds with a wide dynamic range.
Even using a less-sensitive microphone, there was still some residual background noise, although at a more acceptable level. Even the act of plugging a cable into the mic socket can generate some noise so you have to be very careful with your cabling and shielding. But perhaps it's telling that even the demos supplied with the program had their share of hiss.
To prevent aliasing, according to Nyquist's theorem, you should limit your audio input to 10kHz, which is just a little below the frequency you would ideally like to hear a good vocal at (just in case you were thinking of setting up a home digital recording studio).
There are a couple of functions to help improve recording quality incorporated in Audio Trax. The Noise Gate, for example, will remove all audio data below a threshold level you select. This works best when the signal you want to keep is fairly high, which, as sod's law dictates, is usually when you'll need to use it least.
Gain lets you increase or decrease the volume of a section, while Normalise increases the level so it is as loud as it can be without clipping. These take any accompanying noise with them, of course, and are to be used with care. What's really needed is a good filter (or even an average filter). The audio data is actually stored as eight-bit AIFF files so if you have a sound editor you could try running your sound files through its filter.
The point is, with this sampling resolution and sample frequency, the quality is going to be limited. In fact, the specs aren't even up to those of some Atari ST sampler programs. Well, now you know. But then no ST program has managed to combine MIDI and audio data (although C-Lab flirted with the idea but never really followed through) at such a price.
After recording, you can see the results in the Audio Window and you can cut, copy and paste sections of it as you can with, um, ST samplers. These actions are not reversible, however - whatever you do, you do on your original material (you can back it up, of course). But editing audio data is real power stuff. You can create your own N-N-N-Nineteen effects (sorry, but it's as good a place to start as any).
"After recording, you can see the results in the Audio Window and you can cut, copy and paste sections of it as you can with ST samplers."
The two audio tracks can be routed through left, right or both outputs (most Macs only play the left output through their own speaker). You can't record on both audio tracks simultaneously, however, so true stereo recording is out. Shame, that. However, I suspect most users will be happy with two mono channels and treat them as such.
You can mix the two audio tracks together and even mix them with audio data from another file. While the speed of the MIDI data can be controlled by altering the tempo, the audio data plays back at a fixed rate so if you want the two to sync, you've got to get the MIDI recording right first.
There are three manuals - an excellent Getting Started manual, a large Reference manual, both with indexes, and a short Applications manual which doesn't really need an index and doesn't have one. It includes hints on how to use Audio Trax with other applications and it describes the principle of "wild sync", which is basically the practice of starting two processes off at the same time and hoping they'll stay together. Audio Trax can't sync directly to MIDI clocks although it does respond to Start, Stop and Continue messages and Song Position Pointers.
Two HyperCard stacks, which demonstrate the use of synchronised audio and HyperCard demonstrations, are included in the package. However, the processor overhead can still be seen because if you have a few windows open, the sync will drift noticeably.
Data is read to and from the disk on the fly and there seems to be only a minimal buffer, which may account for the reliance on the processor to keep time. Still, close your windows and as well as doing your bit for crime prevention, you can achieve effective synchronised HyperCard demonstrations.
Other hints are given on using Audio Trax with MacroMind Director (two Macs recommended) and recording onto home video. Attractive though these options are, to get the most out of the package, you'll need a fair bit of hard disk space and, unless you're prepared to ditch every recording after completion, some means of backing it up onto floppies.
Trax is an excellent, friendly, budget-priced sequencer (although a true event editor would be useful), which could well suit anyone not requiring all the power of the big boys. Throw in audio recording and it must be a great temptation.
Now, I imagine some of you are wondering whether this could be used to record a demo or even a pressing-ready record (if so, go back and read the review and not just this conclusion).
Well, it's a definite No to the second option - the quality is just not high enough - although that was never Audio Trax's aim. As for the first, well, yes, it could be done but even so the sonic range would be rather limited (remember Mr Nyquist) and likely to be noisy. But if you're careful about how much top you allow the signal and record it well, you could end up with quality which may average out somewhere around tolerable. If that is your aim, do get a demo so you can check the quality for yourself.
On the plus side, let's not forget the ability to cut and paste the audio to produce some interesting vocal effects which would be impossible using tape. The program does, however, lack the editing facilities you get with pro direct to disk systems - which is only to be expected.
Audio Trax is, perhaps, more suited to MultiMedia work (at last - got last year's buzz word into an article) and presentation work as the Applications manual suggests and I could certainly recommend it as a budget option for adding sound and music to Mac-based demonstrations.
In spite of any shortcomings it may have, Audio Trax is certainly enjoyable to work with. The power of digital recording and editing has to be tried to be believed, and this is surely a taster for the personal multitracker of the future - come to think of it, that can't be too far away.
Price £199 including VAT
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Review by Ian Waugh