Recently, one of my clients had a bit of bad luck — his property was struck by lightning. You might think that's uncommon, but it was the second time in 3 years his house had been hit. Last time, the only damage was to the windows and satellite dish next to the tree that exploded. (Afterward, you couldn't find a piece of the 35-foot-tall tree longer than 6 inches.) This time the outcome was worse, with extensive damage to all of the house's electrical systems, including the phones, security, network, lighting, and A/V control.
Because I'd installed the A/V gear, I wanted to know how the surge from the strike got into the house's wiring. I always use surge protection on all network cables from DSL or cable modems that go into an A/V system. But in this case, a telecom subcontractor — not my custom-installation company — had wired the network and phone systems.
During the original installation, I'd verified that there were surge protectors on the incoming DSL lines before connecting the A/V system to the home network. But the lightning struck directly over a buried network cable that connected the guest house to the main house — a line that came directly into the main switch with no surge protection. The surge fried almost every network port connected to that switch, including much of our IP-based control system. Once I found the problem, I had to use some creative wiring to isolate the surge-protected A/V system from the main home network.
Brownouts are another threat to your electronics. The opposite of a surge, a brownout is when the voltage dips lower than what your gear needs to run properly. A surge protector only helps when there's a sudden spike; it doesn't have extra energy to fill in when the voltage sags. But companies such as APC and Panamax have started making battery backup systems (often called "uninterruptible power supplies") specifically for A/V equipment. These also have voltage regulation, and include surge protection for network, phone, and cable- and satellite-TV connections. For $160, APC's BT1000MC provides your entertainment system with full protection from the outside world.
HIGH ANXIETY
Altitude is another potential hazard. Most people in the U.S. probably aren't aware of the problems it can cause, but those of us in the mountain states know them only too well. Since plasma TVs tend to blow power supplies and buzz like neon signs at locations over 6,500 feet, they're rated for different altitudes. (A few "high-altitude" models are rated for heights around 9,100 feet.)
Most of my clients live at between 9,000 and 11,000 feet, and their systems suffer from problems that go well beyond buzzing plasmas. The thinner air up here affects all types of gear that generate heat, causing front projectors, rear-projection TVs, digital-satellite receivers, and even the occasional high-capacity music server to overheat and fail. Several projector manufacturers have introduced a "high-altitude mode" — usually a low lamp-brightness setting coupled with the high cooling-fan setting from the projector's high-brightness mode. (The bright mode is disabled because the fan is already running as fast as it can.)
Ventilation is key when you're using electronics way up in the mountains. Leave as much space as possible around the gear when you're in the high country so the air has plenty of room to circulate.
HOT STUFF
While we're on the subject of heat, there are few things you should know about the warmer parts of the country. A projector is very susceptible to overheating in any space without proper ventilation, but as long as there's some kind of system in place to properly exchange the air in the room, it will usually be fine, even on a warm day. The trouble is, most people don't bother to think about heat buildup when they tack on a home-theater addition. Remember: Heat rises. So when the room starts to feel uncomfortable to you, imagine what it's like for a ceiling-mounted projector. Placing an air conditioner or vent directly above the projector is not a solution, since the rapid cooling of the projector's bulb can cause it to distort colors and ultimately fail. Bulbs are designed to run at a certain temperature, and you need to respect that. If you do cool the room with air-conditioning, just remember to allow for the projector's needs.
And projectors aren't the only components that can have a problem with heat. A friend of mine in Texas has seen the bricks in a house's exterior walls get so hot that they cause the touchpanels mounted in them to overheat and lock up.
THE DEEP FREEZE
Cold can be every bit as rough on your gear as heat. As color touchscreens have become more affordable, some people have allowed the temptation to place them in deck and pool areas to overrule their common sense. While this might be great for summer use, most liquid-crystal screens don't like extreme cold any more than they like extreme heat.
I was once called in to fix a job where an installer had mounted a touchpanel in a sunroom. In summer, the room became an oven when the outside doors were closed, and in winter, the temperature in the unheated space often fell below zero. The previous installer had to replace the panel after every summer and winter. My solution was to install a wireless touchpanel — but it was an expensive solution.
ON THE BEACH
Our next danger zone is coastal areas, with their high humidity and salt-filled air. Good outdoor speakers can handle all kinds of environmental adversity, but the salt fog of coastal states and the high humidity of the tropics are still bad for them. These speakers are tested and rated for exposure to heat, cold, moisture, and salt fog, and a well-designed model will make it through season after season of abuse.
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a. THUNDERSTORMS |
SHAKE, RATTLE, AND ROLL
People think that only the worst earthquakes pose a threat to a home-entertainment system, but the popularity of top-heavy flat-panel TVs has made even minor quakes a danger. It doesn't take a tremendous amount of energy to cause a flat-panel set to topple down onto its owner. In fact, the National Consumer Product Safety Commission says that falling TVs kill about six children in the U.S. every year. The commission also says that 10 deaths between January and October 2006 had been linked to falling TVs. Always fasten your flat-panel set to the wall with a restraining cord. Better yet: Permanently mount it to an arm or bracket attached directly to the wall studs.
TINY TERRORS
We can't talk about danger zones without talking about kids. They might be lovable, but I continue to be amazed by all the ways they find to destroy gear.
I'm glad the days of the VCR are nearly over. The first time I saw the loading tray on a DVD player, I thought about how much harder it would be for kids to stick a peanut butter-and-jelly sandwich into it. Many years ago, a member of my family switched to DVD just to avoid having his kids sabotage his VCR. But his son, upset that his Barney tapes wouldn't work in the new player, decided to relieve himself on the 27-inch CRT set. That child was lucky he didn't shock himself in what could have been a very painful experience. But that just goes to show that no matter how much effort you put into protecting your gear, there'll always be something you didn't see coming.
The best advice is to prepare for every possible hazard. If you live in Tornado Alley, follow the earthquake advice and secure your equipment. If you're in a flood zone, you might want to rethink that basement home theater. Regardless of which danger you might be exposed to, your best protection is still just good ol' common sense.
HUMAN ERROR
One hazard we're all exposed to, regardless of where we live, is bad installation work. If you're about to do some work on an existing installation, proceed carefully.
I recently upgraded a beautiful log cabin (if you can call a 7,500-square-foot house a cabin). After unplugging and removing all the gear in the main closet, I proceeded to prune the cable shrub coming out of the wall. After cutting away about 4 pounds of electrical tape, I trimmed the cable to prepare for a clean patch panel. But as I was removing the cascade of wire, I created some sparks that damaged my cable cutters. After a little investigation, I found that one of the Cat-3 wires (commonly used for sending data through phone systems and home networks) was carrying 120-volt power — something it was obviously never meant to do. After muttering a few choice comments about the previous installers, I found five more low-voltage wires hot with 120-volt power.
This is a dramatic example of a bad installation, but it's far from an isolated one. Just because you're paying somebody to do a job doesn't mean he's a pro. It's up to you to get references before you hire anyone and to inspect all the work once it's done.
Sean Greer is the owner of and senior design engineer at Experience AV Home Theater (ExperienceAV.com) in mountainous Montrose, Colorado.
The Custom Installer: Preparing for a Disaster
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