REALLY WIDE (PSYCHOACOUSTIC) PANNING

The trick I'm about to describe is no substitute for a dedicated 3D sound system, but it does help you create the illusion that a sound has been panned beyond the limits of the speaker placement.

• First, split the signal to be treated so that it feeds two mixer channels and patch a digital delay into one of the channels — for the sake of argument, the rightmost channel.

• Pan one channel hard left and the delayed channel hard right.

• Now set the delay time to around 1 ms with no modulation or feedback and bring down the level of the delayed channel so that it is about half that of the undelayed channel.

• Finally, add a little top to the undelayed channel and take a corresponding amount of top off the delayed channel.

What we have done is to approximate, very roughly, what happens when we hear a sound coming directly from one side.

The ear nearest the sound hears that sound at its brightest as it is almost exactly on-axis, while the same sound arriving at the opposite ear will be lower in level and lower in high frequency content due to the masking effect of the head. It will also arrive around three quarters of a millisecond later because of the extra distance it has had to travel. If all goes well, the panned sound should appear to be slightly further left of the left hand speaker.

Figure 1 shows how this simple patch may be set up, and as an alternative to HF boost, you could try patching an exciter into the undelayed channel. Note that there may be mono compatibility problems with any technique that attempts to replicate natural stereophonic sound using delays or phase shifts, so if mono compatibility is an important issue, restrict the use of such processes to secondary components of the mix.

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LOOSE LESLIE EFFECT

Engineer John Acock reveals the secret of his DIY Leslie effect: The Leslie speaker sound has become synonymous with rock keyboards, but few people have the space to use the real thing any more. Electronic imitations are quite useful, but they don't convey the same organic feel as real moving tweeters and whirling baffles.

One simple trick that really works is to feed the signal to be treated into a small loudspeaker, such as an Auratone cube, and then swing this around on the end of a piece of stout string.

The result may be miked in either mono or stereo, stereo giving the best results, and even a simple setup such as a couple of PZM mics taped to the wall works well. Because of the bass restriction of small speakers, it may be necessary to add a little of the untreated sound with some bass boost applied in order to balance the sound; to create a more complex illusion of movement, you could try making several recordings of the moving speaker and then bounce them all together. Slower effects can be achieved by allowing the speaker to swing from a hook in the ceiling. Another alternative is to suspend the speaker using two pieces of string and then spin the speaker round to twist the string (and of course the speaker cables); when the speaker is released it will spin rapidly as the string unwinds, creating a fast Leslie type of effect.

This kind of experiment seems hard work when you consider that most effects can be approximated using an off-the-shelf multi-effects unit, but it's precisely the organic and unpredictable nature of tricks such as this that made so many early records exciting and unique.

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DUBIOUS DONGLES

Why is it that some Atari-based sequencers work reliably, week in, week out, while others seem to crash whenever you turn your back on them? Whenever a computer crashes, most people blame spikes on the mains supply, and sometimes they're right, but in my experience, the problem can usually be traced to the 'dongle' connector. This is exacerbated when the dongle is part of a larger device such as C-Lab's Unitor, or where it is actually plugged into an external unit, as in the case of Unitor II. These devices place some stress on the connector, and to minimise this, it's essential that the rubber feet provided are attached to hold the unit dead level when it's plugged in. It's also important to set up the computer on a flat tabletop or shelf.

Physical stress aside, the contacts tend to oxidise or build up layers of grease so it's a good idea to clean them occasionally using a soft rubber or isopropyl alcohol on a cotton bud. A specialised contact enhancer such as Stabilant 22 or Tweak is also helpful — try an up-market hi-fi shop for these. Contact enhancers may be brushed onto the cleaned contacts before reinsertion and should help maintain a reliable contact.

The final tip: be as paranoid as you like about backing up data. Even with the best will in the world, computers will crash, usually when you least need them to, so back up your work every few minutes and when the inevitable does happen, you'll be ready for it.