Audio clarity is greatly affected by the quality of the power used to run audio equipment. This is one of the many aspects of live sound that your audience won’t notice so long as everything’s done correctly, but if something’s amiss, then your show can be ruined. In the worst scenarios, your gear can be ruined, too. That’s why it’s important to ensure high-quality power throughout your live sound rig.
Power Conditioners
The number one piece of gear you absolutely must have if you’re running a live sound system is a quality power conditioner, such as the popular Furman M-8Lx. In addition to professional-level surge protection, power conditioners provide clean 
power to sensitive electronics by filtering out noise that can ruin your audio or damage your gear. Power conditioners also frequently include outlet isolation to prevent crosstalk between devices connected to multiple outlets.
Surge Protection
The most basic level of protection you need to consider is surge protection. Sudden spikes in voltage (known as transient voltage surges) can be extremely dangerous to sensitive electronics. Most surges happen when a piece of equipment with a high current draw is turned on. The sudden extra demand causes the service voltage to spike, leading to a surge across the entire circuit. With power amps and racks of gear on individual switches, live sound settings are notoriously prone to voltage surges.
While even consumer-grade power strips boast of surge protection, these devices have two major drawbacks. First is the delay in response that may let through dangerous voltage levels before shutting down. Second, they are self-sacrificial by design, so even when they do protect against surges, their metal-oxide varistors (MOVs) may be permanently damaged, rendering them unusable. Professional transient voltage surge suppression (TVSS) systems safely absorb and dissipate voltage spikes at far lower voltages and shut down, rather than sacrifice themselves, under most circumstances.
Power Filtering
Noise carried by alternating current (AC) can manifest in several ways in your live sound system. The most obvious is broadband noise, which frequently fizzles across midrange frequencies in a deeply distracting way. It can also cause certain frequency ranges to be louder or quieter, like a bad EQ job. In extreme scenarios, a combination of noise and voltage spikes can cause digital equipment to malfunction in odd and destructive ways, causing effects units to shut down and wiping out data.
What to Look for in a Power Conditioner
With so many power conditioners on the market, you will be able to choose from many different sets of features. Here are a few things to look for.
Number of Outlets
This one’s a bit of a no-brainer, but different power conditioners come with different numbers of outlets. Also, some of the outlets may not be controlled by the main power switch.
Outlet Spacing
Some power conditioners trade an outlet or two for a bit of extra space to accommodate wall warts. Depending on the gear you plan to plug in, this could be a nice feature to look for.
Amperage Rating
Most power conditioners are rated for 15 amps, but if you need a 20A circuit, there are power conditioners such as the Furman PL-PRO DMC to choose from.
Voltage Display
An onboard voltmeter (and sometimes an ammeter) can be extremely handy, especially if you’re trying to sort out a problem with your system. They can also warn you before something potentially dangerous happens.
Pullout Lights
Due to the amount of heat they often generate, it’s usually a good idea to keep your power conditioner in the top spot of your rack, so having a set of pullout lights built in can be really handy. Pullout lights are almost exclusively equipped with LED lamps now, but you may find one with traditional incandescent lamps too. BNC or other connections for external lamps may also be available.
Other Power Management Gear
In addition to power conditioners, there are other tools and power equipment you may want to check out. Here are some examples to consider.
Voltage Regulation
If power filtering isn’t enough, you may need a voltage regulator like the Furman M-8X AR. Unlike the simple diode-based voltage regulators used in industrial applications, voltage regulators for media applications use complex circuitry, often employing multi-tap toroidal autoformers to instantly adapt to fluctuations in input voltage while reducing electromagnetic interference (EMI). The result is a stable output voltage and extremely clean power. Virtually all voltage regulators for live sound include advanced power conditioning as well.
Balanced Power
Usually reserved for studio applications where sensitive recording equipment can be affected by even minute EMI (electromagnetic interference) in the AC, power balancing devices apply the same type of transformer-isolated common-mode cancellation to your power that balanced connections offer to your audio signal (this spec for balanced audio is called CMRR or Common Mode Rejection Ratio). If you’re likely to do a lot of live recording with your rig, then a balanced power unit, such as Furman’s P-2400 IT, is a worthwhile investment.
Power Sequencing
Most quality power sequencers, such as the Furman M-8S, include six or more sequenced outlets, which are switched on and off at delayed intervals with the flip of a master switch. Sequenced power supplies are a must if you’re running a series of high-current amps, as the power surge caused by turning on a rack of powerful amplifiers can easily cause power surges that throw breakers, shut down power conditioners, or fry sensitive gear.
Cables and Accessories
Finally, it should go without saying that if you’re going to invest in professional power management equipment, then there’s no sense in scrimping on quality cables and other essential power-related accessories. Properly shielded cables can reduce EMI and other external noise before it even reaches your rack, and in-line filters can take care of power where running a line from your main power conditioner isn’t an option.
If you’re putting together a complete power management system for your live sound rig, give your Sweetwater Sales Engineer a call. We’re happy to put together a custom package just for you.
