It would take a smart man to say exactly why the four track cassette deck has been so successful. It may be the heaven sent device for bands to record demos, but would the various Fostex and Teac machines have sold in such quantities five years ago?

The inception of drum machines and cheap synthesisers has had a lot to do with the recent triumph of four tracks. They've contributed to a change in musical attitude — a move from pub-gigging bands to trios, duos or singles gathered around a rhythm box and a sequencer line.

Certainly the high quality, impressive features and above all affordable price of Portastudios and Multitrackers has helped them win through. But perhaps there wouldn't have been the demand to record unless there was first the new instruments to put down.

Many companies are now investigating the four track cassette market — some in an innovative fashion, others just doing a "me-too" at a lower price. The chief combatants are still Teac, with its history of four, eight and 16 track reel to reel machines, and Fostex, the European face of a Japanese company. Pub chat has it that many of the Teac engineers responsible for developing the first Portastudio, the 144, left to join Fostex, taking their ideas with them.

The 144 and the 250 Multitracker both came out at around the same time and were similar in principle. Each has an integral four track mixer, four meters, logic controlled transport systems and cassettes which run at 3% inches per second — that's twice the usual cassette speed.

Interestingly, the patent for 3¾ ips transports belongs elsewhere and though Teac and Fostex were allowed to have their way with the system, Yamaha couldn't adopt it in their rival machine which consequently has to run at the normal 1⅞ ips.

The 3¾ ips system should have the advantage of generally better sound quality and an improved signal-to-noise ratio — hiss is after all one of the most daunting enemies in home recording. But of course it can't be played on a standard stereo deck. Yamaha and others in the same position argue that if you're investing this amount of money, it's not unreasonably to want to use it as part of your hi-fi system to get the greatest value for money.

Successful and satisfying home recording comes not so much from the quality of the machine — though that obviously plays a part in clarity, fidelity and so on—but on how you use it. Tricks such as bouncing or pingponging three tracks onto one can resolve in gross distortion or muddy reproduction WHATEVER you buy. It's YOUR skill and experience that procures the right sound, and then the results can be remarkably clear and professional.

The 144 was challenged on many points by the 250 Fostex which was a quieter and easier to operate machine. But towards the end of last year, Teac's R and D department slapped on a big grin and unveiled the 244 follow up, with facilities that overtook the Fostex.

For a start there was a parametric EQ rather than ordinary tone controls. Each channel on the mixer has two dual gang rotaries — one control on top of another. The outer ring selects the frequency, while the upper one dictates the amount of cut or boost. In other words you can "design" your own tone controls and tune into a particular band of frequencies.

One parametric runs from 62Hz to 1.5kHz, the other from 1kHz to 8kHz, and there's 15dB of cut or boost — a generous amount.

The 244 came into line with the 250 by being able to record all four tracks at once (the 144 was two at a time) and providing peak overload lights on the meters.

Both machines record on a buss system which, as the coincidentally Red Roverish name implies, transports the signal to the record head. When playing into one of the mixer channels, you set the pan control hard left for the left buss, then depending on the switch selected, that goes either to channel one or three.

Two or four are secured courtesy of the right buss. Playback and mixdown applies similar steps in the reverse order and both machines allow for headphone monitoring out of two sockets (save tape, record with a friend).

Sometimes when you fluff a few notes, you'll want to drop in and re-record just that section rather than the entire track. Each deck makes that possible and whereas the 144 needed a mate to operate the controls while you were preparing to make with the notes, the 244 has a footswitch to do the job, again mimicing the 250.

But it has stepped ahead on what you can do with the signal, or rather where you can send it. For example the old mono auxiliary send circuit of the 144 has been replaced by a stereo alternative on the 244. So when bleeding off part of the signal to route to an effects pedal, you can now pan that output as well as switching it to include or exclude the fader and EQ settings.

But soundwise, there be the rub. The substantial difference twixt the two is their noise reduction. The Fostex employs Dolby C, an update on the commercial B variety found in most home hi-fis, though not up to the rigorous standard of the A used by studios. In the simplest barrack room terms it boosts treble (and therefore hiss) on recording and cuts it on playback in such a way that the ratio between the two is to the detriment of the noise and to the benefit of the signal.

Teac applied Dolby B in the 144, but swapped to DBX in the follow up. This is a dynamic noise reduction system that senses the strength of the signal on tape and varies its filtering to match loud and quiet passages.

One of the major contentions about the quality of the two rivals rests in this area. Fostex devotees claim that the DBX "breathes", especially on bass notes — in other words you can hear the electronics turning themselves up or down. Teac chaps poo-poo this argument, boasting their favourite allows greater freedom for dynamics.

Either company will quote chapter and verse on figures, but... without wishing to duck out of the argument like the true coward one is... both are so closely matched that recording through one hissy effects unit is enough to eradicate any difference between them.

In the end it comes down to ease of use. I've always found the Teac scheme of putting all the inputs around the back to be a total pain in the arse. You're for ever dragging the machine off its shelf in order to change instruments; the Fostex is easier to get at, but makes the mistake of keeping its meters flat rather than tilting them upwards like the 144 and 244. The latter means you can glance across from your keyboard and check that nothing's overloading, where the 250 requires a positive movement of taking your head and positioning it over the top of the deck.