There is one onvestment in your home theater that you can not see or hear and that is the surge protector that will save your equipment in the event of a power spike.

Summer’s villainous lightning, power outages and heat-wave electricity drain aren’t the only threats to your delicate electronics. Even an air conditioner’s compressor switching on can upset the electrical flow, potentially damaging or straining home-entertainment equipment.

A voltage surge lasts 3 or more nanoseconds. A spike lasts up to 2 nanoseconds. Get a surge protector with a lightning-quick response — look for one with a response time under 1 nanosecond. That will minimize equipment damage. High voltages also enter the house through cable and phone lines. Is your HDTV connected to a cable box? The cable box, and the incoming cable line, must be protected too. That goes for a phone line, too, if you use one for TiVo or your network computer. Get a surge protector with cable and phone inputs-outputs.

Most surge protectors use metal oxide varistors, usually called MOVs, to eliminate unusually high voltages. Some little cheapies burn out after one incident.. Look for a surge protector with an indicator light showing whether the protective mode remains active.

One question to ask is, does the manufacturer offer a connected-equipment warranty that replaces any equipment damaged despite being connected to the surge protector? The higher the warranty, the safer you should feel. You are going to find that the higher the warranty amount the higher the cost. I am not sure but it really seems like these companies are more of an electronics insurance policy than anything else

Don’t get a surge protector that diminishes your home theater’s picture or sound. Those same MOVs that protect your equipment also can screw up its performance. In fact if you have a line conditioner as part of your surge protector then you will see and hear better quality than you now have.

Here are two that offer protection and preserve (or even improve) performance without costing a lot of money:

If refrigerators, washing machines, vacuum cleaners or cell phones also affect your home-entertainment equipment, the Max 2 Series could be a savior: It virtually eliminates electromagnetic interference.

When you have this kind of investment it pays to have a surge protector. Your eyes ears and wallet will thank you for it.