Protecting Your Home Theater from Everything

There are many ways to ruin fragile speakers and expensive electronics, but there are just as many safeguards you can implement to protect your equipment. There are well known solutions, such as surge protectors, but power surges aren’t the only threat. You can also overheat amplifiers, melt tweeters, blow drives, burn out bulbs, or short receivers. By following the advice below, you can avoid the issues above and secure a long, healthy life for your equipment.

AC Surge Protector

Likely the most obvious threat to your equipment is a power surge. A strong surge can easily fry all the gear in a rack, and travel through interconnects to reach speakers, subwoofers, and displays. Using an inexpensive surge protector will help protect your gear, but may fail when presented with a powerful surge. We recommend spending money on a quality power center with voltage monitoring that will automatically disconnect power when voltage is too high or too low.  Nice power centers also tend to have higher joule ratings to take larger hits without failing, quicker response time to stop surges before they reach your gear, ground plug protection, noise filtration, and a lower clamping voltage to kick in at lower voltages.

For projectors & wall mounted TVs, "power bridge" type products allow you to only buy one surge protector for all your electronics 

UPS

Related to having a good power center is utilizing an uninterruptible power supply (UPS) for front and rear projection systems. Front projectors and rear projection TVs utilize lamps that get extremely hot. Fans are used to keep the lamps cool, but if you have a power outage while the equipment is running and the fan stops, you may lose a significant amount of lamp life. Since lamps tend to cost a few hundred dollars, it’s a good idea to invest in a UPS to keep the fan running long enough to cool the lamp. Just remember to check the power requirements of your equipment before investing in a UPS. You risk permanently damaging equipment by hooking up an underpowered UPS, which is why we recommend sticking with battery backups specifically designed for home theater gear. Panamax,Tripplite, and APC are good companies to consider when shopping for a UPS.

Coax and Ethernet Surge Protector

As a custom installer, I’ve come across many systems that utilize a nice power center with surge protection for coax and Ethernet; however, rarely are these connections used. This means that surges have a backdoor into your system. If a surge makes it into your home through the coax line, it can travel through a cable or satellite box, and then through the various cables hooked into a cable/satellite box to reach the rest of your gear. The surge could also come into your home through coax, but then pass through the modem and make its way through your home using Ethernet. Note that some power centers will filter out part of the coax signal and cause signal failure, but it’s mostly an issue with older power centers and satellite. Check the bandwidth (> 1GHz)  of the coax connectors of the power conditioner you're planning on buying to ensure it will pass HDTV maximum resolution without any problems.

The Panamax M8-AV-Pro is a solid surge protector with both coax and Ethernet connections

Proper Ventilation

All too often gear is stacked right on top of each other, shoved in a cabinet with no ventilation, or crammed together with no room between components. Each of these situations will cause equipment to operate at higher temperatures than intended, which can lead to poorer performance and deceased lifespan. To ensure cool operation, give each component about 2 inches of space on all sides, drill holes in closed cabinets to allow airflow, and stack the hottest components (typically DVRs and AV receivers) at the top of the equipment rack. In some situations you may want to add a cabinet fan or component fan. A simple solution I often recommend is a fan from Cool Components and a TC-ALTv2 fan controller that will automatically turn on the fan when the air reaches a set temperature. Of course, there are cheaper DIY routes you could use as well.

In addition to cabinet ventilation, you can get fans designed to set directly on top of components

Volume Limit

An easy way to damage your speakers is to crank up the volume too loud. If you push a receiver too hard, the amplifier may start clipping, which turns the output signal into an almost pure constant DC signal. This can cause the wires in the speaker’s voice coils to overheat and melt. That’s not a good thing. Even if your receiver has plenty of power and won’t clip, your speakers can only handle so much power before being damaged. Beyond protecting your speakers, a volume limit ensures that no one ever accidentally turns up the system to ludicrous levels. Most modern AV receivers allow you to preset the maximum volume level in the OSD settings.  Use this feature and only disable it in the rare events when you want to really rock out and want to crank it to volume 11.

Acoustic Treatments

I’m not sure I’ve ever heard someone justify acoustic treatments based on the argument that the treatments will protect their equipment, but it’s a valid argument. Acoustically poor rooms can cause great speakers to sound terrible, most notably; they can make dialogue hard to understand. What do you do if you can’t understand dialogue? You turn up the volume. I've seen this happen countless times. Unfortunately, turning up the volume won't typically help, you just end up driving the speaker too loud and possibly damaging the speaker, amplifier, and your ears. By properly acoustically treating your room, you may notice improved clarity, which means your won’t need to crank up your system just to enjoy it.

Check out these articles for guidance on how to acoustically treat a home theater.

• How Does Listening Room Acoustics Affect Sound Quality?
• Early Reflections in Home Theaters: A Different Perspective
• Listening Room Acoustics: Room Modes & Standing Waves Part I

Subwoofer Placement

Closely related to properly applying acoustic treatments is properly positioning speakers. This is especially true when it comes to subwoofers. As low frequency soundwaves interact with a room, standing waves are created. Standing waves can boost sound at certain frequencies and cause dips at other frequencies. These boosts and dips vary based on subwoofer and listening positions locations. I often demonstrate this to clients by placing their subwoofer in a corner (corners tend to cause the most dramatic swings in frequency response), playing bass heavy music, and asking them to walk around the room and listen to how the bass changes. Invariably, at some locations the bass is extremely loud, while at others it’s so quite you would think the subwoofer is turned off.

This is an awful, but typical, frequency response plot. Notice the -35dB null at 120Hz.

If your listening position happens to be in a dip, you will likely keep turning up the subwoofer volume because it sounds like the bass is too quite. However, increasing the volume won’t help because it’s an issue with the room, and you will end up driving the subwoofer harder and harder until the point of failure. By moving the subwoofer and/or listing position to a more ideal position, you can enjoy more even bass and won’t be tempted to turn up the subwoofer volume to overcome an issue with the room.

To find the best location for your subwoofer, check out our article about the subwoofer crawl. Better yet, adding a second subwoofer to your system will help ensure an even frequency response across all listening positions. Read the articles below for more information on standing waves and subwoofer placement:

• Subwoofer Crawl Technique (YouTube Video Instructional)
  
• Optimum Room Locations for Subwoofers An Analysis
  
• Subwoofer Connection Guide For A Multi Subwoofer System
• Bass Trapping Ideas for Non-Ideal Spaces

Equalization

Instead of taking the time and spending the money to properly position and acoustically treat a listening space, people often use equalization (EQ) to improve sound quality. Rather, EQ should be used after all other solutions have been implemented. At that point, it’s a great option. However, remember to NOT EQ up more than a few dB max. If you apply a slight boost and it doesn't fix a dip, then back it off.  If there’s a dip in the frequency response of your system,  boosting levels at that frequency typically won't solve the problem. First off, it won’t help if the issue is related to room acoustics. Second, it’s easy to damage speakers and amplifiers by boosting certain frequencies too much. Therefore, it's usually a good idea to NOT EQ up. Only EQ down.

Conclusion

The list could go on, as there’s no shortage of ways to damage your gear (dust, humidity, direct sunlight [depending on cabinet finish], toddlers who enjoy poking dome tweeters), but I think we've covered the most common issues. Exercise proper setup and placement to optimize your  listening environment.  It's also a good idea to invest a little of your budget towards power protection and  improving your room acoustics.  You will get more sonic enjoyment and longevity out of your gear by taking these steps.  Share below if you have any other suggestions, or stories of how gear was damaged. Safe listening!