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Gigging Safely With A PC

PC Musician
By Martin Walker

Increasing numbers of musicians want to gig with their computers — but home PCs are fragile and laptops may not always be powerful or adaptable enough. What are your alternatives, and what measures can you take to protect the centrepiece of your live set?

Given the amount of great music that's emerging from PC-based project studios, it's hardly surprising that musicians want to take their computers on stage too. Gone are the days when we had to rely on DAT or Minidisc backing and play live guitars or keyboards over the top; nowadays many musicians want to perform more creatively on stage with a PC, either mixing a bank of sequenced loops in real time, playing back sequenced songs to be treated while they're triggering soft synth lines from MIDI keyboards, or performing with live-performance software instruments.

So far, so good, but as Craig Anderton pointed out in SOS January 2004, having your live performance totally dependent on a computer is not a secure feeling.

Shock Treatment

No doubt a few of you do take a desktop or tower PC to occasional gigs, but these really must be treated with kid gloves, as they're not robust enough to survive rough handling. Whether your PC is being taken to a gig in a car, put in a van for longer journeys, or subjected to courier delivery, the two big problems during transit are individual shocks and vibration. For the occasional short car journey, my desktop and tower computers have always been quite safe strapped into a car seat, but for longer journeys (especially when moving house), return them to their original boxes with their properly engineered foam inserts to absorb vibration and shocks.

After a long journey, I still remove the side panel of my computers and have a quick check that the PCI cards, RAM sticks, cables and so on are still firmly in place before I switch the computer on. However, you simply can't do this kind of checking every time you arrive at a gig, so I'd strongly advise against regular gigging with a standard desktop or tower PC.

Some Practical Tips

  • See clearly: Everyone has their own way of using software when performing live, but the last thing most people will want to be thinking about is navigating through menus and launching new dialogue windows when strobe lights and dry ice may be involved! Instead, you ideally want to have every window you need on screen all the time, and preferably split across multiple screens to make everything as clear as possible.
  • Take a shortcut: I daresay some brave souls use a mouse live, but you want to minimise the chances of clicking in the wrong place, so keyboard shortcuts seem far safer to me. The best solution must be performing with one or more external MIDI controllers having dedicated switches, knobs, and faders — plus, of course, a normal MIDI keyboard.
  • Latency live: While we're on the subject of safe use live, don't be tempted to run your audio peripheral at anything lower than a rock-solid buffer size — it might be tempting to set a lower latency to make your software feel more responsive, but if your soundcard starts clicking and popping through the PA you'll wish you hadn't, and if your sequencer stops altogether due to a CPU 'maxout' the stage lights should ensure that the audience sees your red face!

Rackmounting

A rackmounting case like these ones used by (top to bottom) NuSystems, Red Submarine and Millennium Music will protect your PC far better than any desktop or tower case when on the road, and they have lockable front panels to prevent tampering while they're on stage.A rackmounting case like these ones used by (top to bottom) NuSystems, Red Submarine and Millennium Music will protect your PC far better than any desktop or tower case when on the road, and they have lockable front panels to prevent tampering while they're on stage.So if it's inadvisable to take a standard PC on the road, how about buying or building a PC in a 19-inch rack case, and bolting it into a rack, with hardware synths, effect units, and so on?

Many musicians do this, and most of the specialist music retailers, including Academy Of Sound, Carillon, Digital Systems, Digital Village, Millennium, and Red Submarine, offer a 4U- or 5U-high rackmounting system option with their PCs. Compared with most floor- or desk-mounting PC cases, industrial rackmount cases have various things in their favour. They tend to be far more rugged, generally with 2mm-thick steel bodywork that will withstand accidental impacts from other objects (the Carillon rack PC's front panel is particularly sturdy, being die-cast in aluminium alloy), and they also tend to have reinforcing bars to prevent PCI cards becoming dislodged in transit. If your PC is bolted into a heavy rack with other gear, it's also far more difficult for a casual thief to walk off with, especially if you use security bolts. Do bear in mind, though, that the final weight of a rackmount PC will exceed that of most power amplifiers, so not only will its front panel need bolting to the rack, it will require further support at the rear.

Most rack cases have front fans, with dust filters to prevent cigarette smoke causing internal damage (another bonus in a live situation), and many have lockable front doors to prevent stealing. In some cases you won't even be able to switch the PC on or off without opening the door, which is ideal for gig security, although for the same reason you should keep the keys in a very safe place, and never leave them inserted when the PC is unattended — that's just asking for trouble!

The cons for the typical rack case are higher cost (a moulded PC case costs about £30, an aluminimum MIDI tower about £70 and a rackmount case £150-200), and slightly less expansion potential for further drives than in a MIDI tower or desktop case — rackmount case dimensions tend to be smaller. Moreover, for the live user a rackmount case doesn't automatically guarantee greater robustness. Yes, the case itself is stronger, and your PCI cards may be strapped down more securely, but the other internal components are still prone to shocks and vibration. (The Carillon's rack ears are backed with vibration-absorbing rubber gaskets, which will certainly help.) The PC components inside a rackmount simply aren't all that robust, and may not survive the shock of being accidentally dropped a few feet by a roadie, whereas I've known racks of MIDI synths and hardware effects happily carry on even after being dropped down a flight of stairs. Nevertheless, the dealers I spoke to confirmed that many customers do gig with their rackmount PCs, for convenience and security, but admitted that they're not ideal for regular touring unless enclosed in a dedicated flightcase with a foam lining designed to absorb knocks. Unfortunately, such cases aren't cheap, especially custom-built ones, so many musicians cross their fingers and carry on without.

Having given all these warnings, there are ways to protect the most sensitive PC components, so let's look at some DIY solutions to safeguard the mobile PC.

Drive Protection

Fitting your hard drives into removable 'caddies', as seen in this system from Red Submarine, means that you can remove these most fragile PC components from your PC before taking it on the road.Fitting your hard drives into removable 'caddies', as seen in this system from Red Submarine, means that you can remove these most fragile PC components from your PC before taking it on the road.The most vulnerable parts of any PC are its hard drives, which can be damaged by excessive vibration and sudden mechanical shock. This can result in them developing bad sectors that can't be read or written to — then these need to be specially marked as such by a utility such as Windows 98's Scandisk or Windows XP's Check Disk, to avoid these sectors being used again. After a bad shock the drive may not even spin up again at all.

Drives can withstand much larger shocks when inactive than when powered up, as shown in the 'Environmental' section of spec sheets. A typical figure for 'non-operating' shock is 350G for 2ms, whereas operating shock might be just 60G for 2ms, equivalent to a drop of just a few inches onto a hard surface. Vibration levels of around 1G RMS can often be tolerated when the computer is powered down, but only around 0.6G when spinning.

Molex SilentDrive sleeves from QuietPC (www.quietpc.com) are primarily designed to absorb acoustic noise, but their thin decoupling foam lining is also quite effective as a shockmount, and absorbs external vibration during transit. They are widely used by specialist music retailers for silencing, installing into a 5.25-inch drive bay. You then mount your 3.5-inch hard drive inside them. However, some drives run too hot to be enclosed in this way, and the sleeves don't suit the new SATA (Serial ATA) drives. Another solution might be the similarly-priced NoVibes cages from NoiseMagic (available in the UK from www.chillblast.co.uk), which can be even more effective at absorbing vibration. Again, they mount in a 5.25-inch drive bay, but suspend the hard drive in a cradle of three high-tension rubber bands. You won't be concerned about your drives overheating in one of these cages, but I (and various dealers I've spoken to) have always been a little wary of drives jumping out of the cradle altogether during transit.

Using Laptops Live

Plenty of musicians seem to be taking rackmount PCs on the road, so that they can benefit from the fastest processors and multiple large hard drives, and the ability to rackmount their audio breakout boxes, MIDI synths and hardware effects alongside the PC. However, many others have already found a somewhat more obvious solution for the smaller gig: using a PC laptop.

If you're thinking of using your PC laptop live, make sure you invest in a security cable like the one advertised here, to lock it to a heavy stand.If you're thinking of using your PC laptop live, make sure you invest in a security cable like the one advertised here, to lock it to a heavy stand.You may not be able to buy a laptop as fast as the fastest standard PCs, but for most purposes they are perfectly adequate for live use, as well as being far easier to transport. You can take them as hand luggage on a tour (even abroad) and a suitable padded case is far less expensive than buying a flightcase for a standard PC.

Desktop-replacement laptops are popular live because the fastest models offer more power than Centrinos, as well as having larger 17-inch screens that are easier to see on stage. And, of course, the noise of their cooling fans won't worry you in a live environment. However, a Centrino model will be perfectly adequate for many gigs, if you don't want to run loads of plug-ins and soft synths simultaneously.

Because laptops are routinely moved about, the design of their hard drives may already have benefited from extra attention paid to shock and vibration protection. For instance, the 40Gb Seagate Momentus drive in my Centrino laptop is not only extremely quiet, but also incorporates G-Force Protection for non-operating shock protection and 'QuietStep ramp load technology' for operating shock protection. Together they provide operating protection against shocks of up to 225G for 2ms (typical 3.5-inch hard drives only offer around 50G to 60G) and a staggering 800G for 2ms when switched off.

Still more reassuring is that laptops are fairly immune to mains problems, since even if there's a complete blackout they will automatically carry on with their integral battery power for perhaps an hour in the case of a desktop replacement model and several in the case of a Centrino. Do make sure you've chosen 'Always On' for your Windows power scheme, though, to avoid a sudden drop in CPU performance when the battery kicks in.

Placing your laptop on a foam pad is still a wise move to avoid vibration problems, and a dedicated and rugged stand should help it last the course, too. For security reasons it's also well worth investigating some form of anti-theft device — nearly all laptops feature a Security Cable Connector on their back panel to thwart opportunists, and to this you can connect a galvanised steel cable that you loop around a heavy and preferably immovable object and then lock with a key or combination. Some models can also be used to protect external drives at the same time, while other devices can fix your laptop directly to a stand or desk.

Removable Drives

The ultimate solution to the problem of drive protection during transit has to be removable caddies, also known as drive drawers or racks. You bolt the outer docking station into a 5.25-inch drive bay, just like a CD-ROM drive, plug your PC's internal IDE and PSU cables into its rear connectors, then mount your drive into the caddy itself and connect its IDE and PSU connectors to the internal caddy cables. The caddy is then pushed into the docking bay, and you turn the supplied key in the caddy's lock before switching on your PC.

Quite a few musicians now use these caddies, primarily as a way to easily move from one audio project to another, by unplugging one drive and replacing it with another. Buying multiple drives and using a new one per project is also an ideal way for studio owners to cope with clients returning to remix some tracks, especially now that drives are relatively cheap.

Always fit a good-quality power supply to any PC that's on the move — cheap models are notoriously unreliable. This high quality SilenX PSU has had its capacitors treated to prevent vibration problems.Always fit a good-quality power supply to any PC that's on the move — cheap models are notoriously unreliable. This high quality SilenX PSU has had its capacitors treated to prevent vibration problems.For live use, caddies mean that after powering down your PC you can simply remove its most vulnerable components before transportation and place them in a well-padded case. At the gig, as long as you keep your drives with you until the soundcheck, you have the reassurance that if your PC gets stolen your data is still intact (although, as always, you should still have it backed up elsewhere for safety).

You can already buy PC systems featuring drive caddies from specialist music retailers, including Carillon, Philip Rees and Red Submarine. It's also possible to purchase caddies to fit to other PCs. It's well worth buying a high-quality caddy. The cheaper ones are made of ABS plastic and generally support IDE drives up to 7200rpm spin speed and ATA133 standard, while more expensive aluminium ones are stronger and designed for drives up to 15,000rpm. The majority are for parallel IDE drives, but you can now buy models suitable for SATA drives as well. Prices range from around £30 to £45.

Incidentally, anyone who has tried in the past to buy one docking station but multiple caddies to use with it (they are nearly always sold as a pair, so you end up having to pay more for parts you don't want) will be pleased to hear that as a result of my enquiries Red Submarine are now offering this option for Lian-Li's RH-32 model. By the time you read this you'll be able to buy the complete unit from them for £27.95, and extra caddies for £17.95 each.

Since you're (in effect) placing a hard drive in a sleeve, again beware of overheating. Some caddies have cooling fans for this reason, and that might make them less suitable in the studio where you want minimum noise. This won't matter for live use, of course.

Avoiding Power Problems

We all know that, despite the great improvements in the launch speed of Windows XP compared with its predecessors, it still takes a couple of minutes to boot up a PC from cold. Then there's the time it takes to launch the music applications themselves, and load up the required song plus plug-ins, soft synths, and so on.

One way to avoid some of this delay during your soundcheck is to use the Hibernate feature of modern PCs to save the entire contents of your system RAM onto your hard drive, so that when you return to the desktop it will be exactly as you left it, complete with all running applications. Unfortunately, some PCs don't recover properly from Hibernation, and some soundcards also seem to have problems with it, so you should thoroughly test out this idea before relying on it live — if anything goes wrong, you'll have to reboot anyway.

Having to reboot the PC is the most dreaded scenario for a live musician, as the audience is unlikely to be very impressed with minutes of silence while you reload everything — and, of course, unless you're a really laid-back performer, a computer crash could seriously unnerve you.

Obviously, you should make sure your PC is as reliable in everyday use as possible, by installing latest driver versions and generally keeping it 'clean' and virus free. Even if you do this, though, there's another potential cause of problems on stage. If you get a mains 'brown-out' (a drop in mains voltage normally signalled by the lights dimming) or a blackout (when the power disappears altogether, either momentarily or for a longer period), your rackmount PC may crash, either locking it up and requiring you to reboot, or causing it to spontaneously reboot.

Unless you really like living dangerously, the answer is to buy a UPS (Uninterruptible Power Supply), which can filter out mains spikes and even survive several minutes of complete mains blackout. Essentially, a UPS contains batteries that are normally trickle-charged by the mains supply, and when the mains fails they kick in to power an 'inverter' circuit that generates the normal AC mains voltage for as long as the battery power lasts. In most cases, the UPS will only need to supply a few hundred watts for a couple of minutes.

Some UPS units run their inverters continuously, to generate a clean interference-free 'mains' signal. In a live situation, this will also provide greater protection from incoming spikes, such as those caused by some stage lighting systems. However, most PC power supplies do have some interference filtering built-in, although it may be worth adding a filtered distribution board to provide a little more protection.

Finally, one of the most annoying power problems has to be unexpected hum or background noises from your CPU/mouse/drive/graphics card suddenly being heard in the PA. Even if your PC audio sounds perfect in the studio it's worth buying a DI (Direct Injection) box to cure such ground-loop problems live. Suitable stereo models, such as Behringer's DI20, are available for around £20.

Anti-vibration Measures

Having dealt with the PC's most shock-prone components, let's turn to the smaller details and see what else can prevent transit damage. During regular journeys, vibration may eventually cause normal screws to work loose. The most potentially troublesome components are PCI and AGP expansion cards: if these become unseated the result may be obscure problems ranging from intermittent crashes to an inability to boot up at all. However, hard drives, cooling fans, PSUs and even the motherboard will most likely be held in place by screws. Even if your PC rackmount case has a reinforcing bar to hold expansion cards in place it may be worth adding anti-vibration measures if the PC goes on regular journeys.

The simplest and cheapest measure is a dab of paint between the screw and whatever it's securing, which should stop it rotating. Alternatively, it may be worth trying the rubber grommets sold for fan and drive mounting. Be a little careful using these with fixed hard drives, however: they may reduce the amount of vibrational noise from the drive that enters the rest of the chassis, but they may also allow the drive to bounce about more during transit, increasing its quota of shocks.

I/O connectors can also come loose during transit, but this can largely be prevented by careful attention to wiring up the loom with ties to various points on the chassis to prevent the cables from pulling on the connectors. You should also tie down any unused PSU connectors, to prevent their exposed pins accidentally touching other components. Other large internal components, such as FanMate controllers, should also be tied down to the chassis if possible. RAM sticks can't be tied down, but you could try putting rubber bands around their clips to prevent them popping out of place.

Modern motherboards don't tend to have large unsupported components (such as capacitors and inductors) on them, but power supplies do, and cheap ones are notorious for breaking down anyway, even before one considers problems due to vibration fatigue of component leads. When I recently reviewed a new SilenX PSU I was pleased to see that its internal components had been immobilised with rubber or potting compound, or glued to other components nearby. These measures not only made it quieter, but will also ensure that it's less prone to 'travel sickness'.

Final Thoughts

Even if your computer is rackmounted, once it's in position on stage it's worth trying to prevent vibration — from a PA, nearby drumkit, over-active vocalist or dancer — from causing problems. As explained previously, this can permanently damage hard drives. If you find yourself on a 'bouncy' stage, try to choose a setup position that minimises the problem, even if this means you're not centre stage! Again, having your PC mounted in a properly-designed flightcase will help.

It may pay you to set up two drives in a RAID (Redundant Array of Inexpensive Disks) configuration, not to 'stripe' them for faster performance, but to mirror your data so that if one drive fails the other can carry on. Also, avoid placing your PC near to any large speaker cabinets that contain strong magnets. Hard drives and magnets don't mix!

By the way, don't rule out taking a Minidisc or CD player with you as a backup: if the worst happens and you need to reboot your PC in the middle of a set, at least the music can carry on while you sort out the problem. Some musicians find Minidisc players more reliable than CD players on stage, as they tend to have larger buffers that will survive longer periods of vibration without the audio stream being interrupted. Both CD and Minidisc players will benefit from being placed on a foam pad to isolate them from vibration.

Published June 2004