That it was a beautiful clear, warm evening in Tampa came as much to the relief of the Pink Floyd crew. The shows on the way to Florida, in Houston and Atlanta, had been drenched by the rain but for this one the heat of the day was still lingering, putting the 70,000 crowd, covering the age range 10 to 45, in a relaxed and good-natured mood.

It had been seven years since Pink Floyd's ast studio album and supporting tour but they are back with The Division Bell, which is number one in 16 countries around the world, and a tour that practically sold out when it was first announced. The band still featuring David Gilmour, Nick Mason and Rick Wright started the European leg of the tour in Portugal at the end of July and are due to play ten dates at Earl's Court in London during October.

With the new tour, the band wanted to get back to the scale of production that they became famous for with The Wall. While it does not have the same theatrics, it certainly delivers a huge production, meshing lights, lasers, pyrotechnics, 61m projections and a massive sound system.

'They kinda make their own stadium, man,' an awe-struck fan said to me at Tampa Airport. It sounds extravagant but that's the intention, as Monitor Engineer Seth Goldman confirms: 'We're very much in our own environment.' The foundation of this is the massive band stage, with its in-built surrounding 'skirt'; there is only one of these and it is broken down and rigged for each show. Rising above this is an arch which supports the lights and projection screen; three of these alternated during the US leg, while two will leap-frog each other in Europe.

On either side of the stage are two towers, which serve the dual purpose of containing the main front-of-house sound system and being home to the trademark inflatable pigs, which pop up during One of these Days at the end of the first half of the show. Because it's Floyd, there can't be just straightforward left and right stereo; the band has been using 'live' quadraphonic since the mid 1970s, and this tour features three quad stations, plus a delay stack directly behind the mixing tower.

An emphasis on sound is something that Pink Floyd have always shown, down to forming their own sound rental company during the early 1970s. Although the band no longer owns Britannia Row Productions, it still provides equipment for their tours, which offer the perfect outlet for its specialist systems. Bands having been playing huge venues, both outdoor and indoor, since the late 1970s, it is only during the last ten years that dedicated long- throw loudspeaker systems have- started to appear.

Brit Row holds the worlds largest stock of one of the leading models, the Turbosound Flashlight, which dominates the current Floyd tour. The front-of-house system is made up of 32 Flashlight highs and 32 low-end units per side, supported by three units left and right of the wider dispersion Floodlight for near audience in-fill.

This reinforcement is further reinforced by nine of the new underhang cabinet, which, like Floodlight, was designed by research house unktion One (run by original Turbosound founders Tony Andrews and John Newsham) and licenced to Turbosound for manufacture. These are arranged in three lots of three along the 'skirt' of the stage.

One of the design criteria of Flashlight was to deliver clear, well-defined sound without the need for delay towers. This the system does, but a delay stack is still need to fill in the area directly behind the mixing tower, a 4-level construction that houses the sound mixers, a hospitality suite, lights-lasers and film projection. Right at the top of this lurks a mirrored rotating ball, which makes a startling appearance during Comfortably Numb.

Ironically, the audience probably noticed the three quad stations more than the visually commanding left and right stacks. Each of these contains eight Flashlight cabinets and four Floodlight boxes. Early on in the preproduction of the tour, it was intended to have the fourth quad cluster suspended over the stage from the semicircular truss that 'contains' the show. However, the height at which this is set made it impossible, so the fourth quad signal comes from the middle of the left and right stacks, fed from a subgroup on the main desk.

The front-of-house mixing position is oversubscribed with consoles, featuring two Yamaha PM4000s, which, over 80- channels, handle the instruments and vocals; a PM8000 for all effects returns and tape playback, still a major part of the Floyd's shows after all this time; and, although the smallest of all the desks, perhaps the most innovative and important, a custom-built quadraphonic Midas XL3.

This one-off was designed by Brit Row, with the blueprints being faxed to the US so that the man who operates it knew what was going on. Dave Lohr ran the quad and effects on the last Floyd tour, which makes him, along with the band's Mixer Andy Jackson, a front-of-house veteran. The other two Engineers, Colin Norfield, who shares ront-of-house duties with Jackson, and Engineering Manager Paddi Addison, are making their first appearances with Pink Floyd.

The XL3 is a dedicated 16-channel quad board, which features two manually controlled joysticks.'Because we need four outputs and joysticks to pan, we needed a board that was designed to do quad, rather than making do with a conventional stereo desk,' explains Dave Lohr. 'The quad is used to heighten what is going on on stage it adds ambience to the performance.'

The effects and various voices come from two sources: either one of the two Otari 8-track tape machines nestling at the back of the mixing position, or from digital samplers on stage, which are triggered by the musicians. This last move would appear to be a fairly recent one and is used for much of the newer material, including the samples of Professor Stephen Hawking on Keep Talking. These, along with four channels of reverb and four channels of autopan, are fed to the joysticks and then panned around. Any of the sources coming through either of the two PM4000s or the PM8000 can be routed through the XL3, and either be panned or have ambience added to them. Likewise, anything from the XlJ can be fed hack to any of the other boards: in this way the fourth quad feed is sent to the main PM4000 and then to the front-of-house stack.

'You've got to mix the quad for the distances,' says Lohr. 'However, you don't want to kill the people right at the back but you want to make sure that the people below get it as well. The quad wasn't really designed for stadium work, though, and I told Dave [Gilmour] this. It works great in arenas.

Surprisingly, this whole high-tech setup was designed around analogue open-reel tape machines, but, as Lohr explains, this is what Pink Floyd know and are used to. they wanted to use the two-tracks again and they're a tried and trusted method. With SR it's close to what digital would sound like. Digital systems have transportation problems they're not really practical for touring work yet. Although the band is generating some of the effects on stage using samplers.' Despite this pivotal role, the XL3 is not the main console in the front-of-house setup: it was designed so that any board could feed inta any other. 'The whole thing is linked up as one,' explains Colin Norfield. 'The chain comes through the instrument and vocal desks' Ithe PM4000s , from which you can either send to the effects console fthe PM3000I or to the quad panner. The Yamahas have their own buzz link for the VCAs and mutes,' while the rest goes via XLRs to multiconnects. All three of these desks then link into the quad. Anything can be sent to any of them.'

The instruments and vocals build up across the two PM4000s from left to right, starting with the drums and percussion (which Norfield calls his 'baby') and progressing through the other instruments. The right-hand PM4000 primarily handles the vocals and keyboards, with the output from both being sent to the PM3000 to be 'treated' and then, finally, routed to the quad board to be distributed.

Pink Floyd's sound has always been very effects orientated, both in terms of voices and noises suddenly popping up out of nowhere, and weird and wonderful ways of processing the vocals and instruments. Despite the sophistication of much of the system, most of the tape effects are played in manually. Only the introduction of Money cash registers, the clanking of coins, is hooked up to time code. This section is driven by the tape, the band taking its cue from a SMPTE click track that also runs the projection. 'In the past, the band have used a lot of time code,' says Lohr, 'but they felt locked into it, so they use less now.'

Processing effects appear on just about everything going through the desks, although the drums and percussion get most of this. There are 24 Drawmer gates across all the drum feeds, AMS reverberation on the snares, Roland SRV2000 reverb over the toms and percussion, and DPR 402 compression on the bass drums.

The vocals are not left out, with a mixture of tc electronic 2290s and the new Roland SDE330 being used for effects on the lead and backing voices. The delay returns from these units are fed to the PM3000 and then into the quad board. A quad-panner, the SPX900, is used for a specific effect during One of these Days, where the signal is panned between front and back and left and right. Two Lexicon PCM70s are used for quadraphonic reverb. Lead Guitarist and Vocalist David Gilmour has a BSS FCS8960 specifically for his vocals.

The delay and quad stations are equalised by a bank of BSS Varicurve remote units, controlled through a remote interface. 'We can control these either from the front- of-house position or by a radio unit wandering about the field when we're setting up,' says Paddi Addison. Power for the front-of-house system comes from 14 racks of amplification, each one containing two BSS 780s for the low and low-mid cabinets, and two 760s on the high- mid and high units. The delay stack and three quad stations each have two racks to drive their loudspeakers.

The monitor mix is equally complex and important, but only has one person in charge of it. Seth Goldman has worked with the Floyd for over 20 years, and in the sometimes long gaps between their tours has also monitored for David Bowie and Mariah Carey. Two Midas XL3s by the side of the stage take 80-inputs and give 22 mixes. These are distributed to the band through a mixture of floor wedges (the Turbosound 1xl5) and the Garwood in-ear monitoring system. 'It's a sophisticated system, but it's still very straightforward, although a little on the large side,' explains Goldman. 'The main desk is mostly used for the floor wedges, which everyone has. The in-ear moulds complement these and are used mostly by the two drummers and the sax player, who wear them throughout the show.

Others in the hand may want to use them if they're getting a lot of slap-back from the arena. I use them all the time, which allows me to walk around the stage and keep tabs on what is going on. They give a lot of freedom.'

Flexibility appears to have been built into this whole system, giving the players communication with Goldman and, in some cases, control over their own feeds. Brit Row have designed a buffering foot-pedal that takes a microphone out of the main mix and turns it into a talkback unit.

David Gilmour has the luxury of a VCA crossover which allows him to adjust the level of his vocals in his own wedge by means of an external button on the mic stand.

'This gives him total level control over what he wants to do,' says Goldman. 'I set things up and tweak it, but it's usually only very minor up and down movements, especially when the vocal is a little more laid back.' This philosophy extends to the whole setup, with the BSS 960 graphic equalisation, Varicurve 9260, BSS 402 compression, 502 gates and Yamaha SPX990 effects units being set up every day and only adjusted where necessary.

'The Varicurves are pretty much set, while the EQ on the floor monitors changes a bit each day, but not much because everything is very much in our own environment,' Goldman says. 'I fine tune all the monitors everyday but it's still a complex mix, with lots of cues coming in.'

Then with all this going on, it all seemed to work well, producing a clear and fully extended sound, the track Sorrow in particular reaching the parts you'd rather it didn't.