Soon digital home recording could be available for £500 using floppy disks. Chris Jenkins reports on plans for a new system

Most of us will be used to the idea of using high technology in producing music. Some may even have dispensed with conventional instruments altogether, and be making music entirely with computer systems feeding into sophisticated processing units.

The latest technological revolution from America may change even this. Soon, ALL your audio recordings could be digital, and eventually both signal processing and the creation of actual sounds could be handled by flexible, enormously powerful hardware/software systems, no more expensive than a good hi-fi set-up.

Though the development of magnetic recording tape was the single most important breakthrough in the history of the recording industry, in some senses it's the structure of the tape itself which has held back audio development.

Obviously, the ease of editing, the possibilities of multitracking and the ability to re-use magnetic tape makes it ideal for many recording purposes. But the method by which it operates, relying on the polarisation of metallic particles in response to an input signal, sets limits on the sound quality possible. There will always be background hiss on magnetic tape, no matter what chrome formulas, noise reduction systems, and complex studio noise gates are used in recordings, and these limitations show up particularly when using the ⅛" cassette format.

Hence the introduction of Compact Disc which, as you'll probably know, does away with many of these problems. The sound signal is recorded digitally - in effect, as a stream of 1's and 0's - and is immune to the problems of background hiss.

In their place, the problem with CD's digital, laser-decoded, indestructible disks is the sheer impossibility of re-recording or editing the disks themselves.

DIGITAL AUDIO RECORDER

CompuSonics, a small American company, seem now to have married the convenience of magnetic tape and the audio quality of Compact Disc with the DSP-1000 Digital Audio Recorder.

Professional music studios have for some time had the use of digital recorders which store audio signals at enormous 'sampling rates' in volatile memories, preserving sound quality while enabling music to be edited much as one would rearrange characters in a word-processing system. Indeed, CompuSonics produces such a system, the DSP-2002, a sixteen-bit system with up to 570 megabyte storage on hard disk, costing an enormous amount of money.

The consumer version overcomes the cost problems of digital storage by using conventional 5¼" floppy disks. Although floppies are similar in construction to magnetic recording tape, with a plastic base coated with magnetic material, the similarities end there. Floppies are circular, have holes in the middle like Polo mints, and are protected by cardboard sleeves. They're not very robust, unlike Compact Discs, and are particularly prone to damage from sticky fingers or cups of tea.

The DSP-1000, when the final version hits the market later in the year, will be able to digitally encode hi-fi stereo sound on a high-density floppy disk, which would normally be able to record only a few seconds of digital audio if it used a recording method similar to that of Compact Disc. The secret is a revolutionary data compression method which uses psycho-acoustics - studies of the way sound is perceived - to determine which parts of an audio signal are essential to the listener. Sounds which are too soft to be perceived can be removed from the data without affecting the overall quality, by the intelligent software in this machine.

The sixteen-bit digital-to-analogue and analogue-to-digital converters used in the DSP-1000 resemble those found in Compact Disc players. The difference of course is in the storage format, which when perfected would open up a number of intriguing possibilities. Steps towards this are on hand in the forming of the DSP-2000 AudioComputer, currently operating as digital mixer/recording environment but soon to feature a staggering range of additional features.

Digital audio data could, for instance, be transmitted over telephone lines via a Modem attached to the player. Very complex signal processing could be carried out by software rather than expensive hardware; noise reduction, click elimination, stereo image enhancement, equalisation and effects such as flanging, phasing and digital delay could be yours for the cost of a new item of software. The 'hardware' of a typical home studio could be reduced to a plastic box full of floppy disks.

The digital encoding system also offers the possibility of creating new sounds, not just manipulating them; a whole new range of synthesisers using this technology could revolutionise music making.

Although the DSP-1000 hasn't been seen in its production form, early figures indicate that frequency response should be around 20 to 20,000 Hertz +/- 0.5dB, with negligible harmonic distortion, zero wow and flutter, and dynamic range, signal-to-noise ratio and channel separation over 91 dB.

Analogue cassette and open reel decks, hi-fi video cassette recorders and digital audio adaptor/VCR combinations would probably be unable to compete with the low cost and high power of such a system. American experts reckon that once on the market, the cost of the floppy disk recorder might drop to around $500.

Since the CompuSonics principles were demonstrated on BBC's Tomorrow's World, when the floppy disk recorder appears in the UK, hopefully later this year, if it follows the US plans it will be marketed through carefully selected outlets, and should be able to record 45 minutes of CD quality stereo sound on one high-density floppy.

MULTITRACKING

The most interesting possibility for the home recordist would, of course, be the introduction of a multi-track version, with facilities similar to the huge professional digital recorders, at a realistic price. Theoretically, the number of tracks used need only be limited by the total storage available; if you wanted to produce an eight-track recording, you might have a limit of ten minutes, but you could also work in sixteen-track with a five-minute limit. The combination of power and affordability would make many producers of more conventional equipment reconsider their position."

Contact: Ranson Audio, (Contact Details).