Q. What is the best way to calibrate my 5.1 sound system for movies? Whenever I watch a movie I am always adjusting the sound. - Jim, New York
A. Getting the sound right in a home cinema is a huge part of the complete movie experience. You can spend hours (with really expensive equipment) tweaking the sound (using parametric equalization) until virtually every audio lump and bump in the room has been smoothed out. Making these adjustments will take a great deal of skill, time and money. However, there are some basic things you can do yourself which might take a bit of time but not necessarily a lot of money.
Let’s examine the room. Is it full of hard surfaces and lots of glass? You will notice an echo when you clap your hands - this is bad! Ideally, you’ll want to have fewer hard surfaces near the seats and area behind it. If this is a problem, think about placing a rug on the floor or even on the wall behind you. This will stop the sound from bouncing off the wall and echoing around the room. Get this right and the rest can follow.
You are going to need a tape measure, a THX DVD and a sound pressure meter. The sound pressure meter from Radio Shack is generally seen as adequate and will set you back $50.00. A number of DVDs have the THX test patterns and audio on them (“The Incredibles” springs to mind), so you might not need to buy one.
It’s time to place you sub for maximum effect. Move your favorite chair or couch out of the way and put your sub there temporarily. Play something with good bass (or a bass test tone from a DVD) and walk around the room to find out where the bass sounds best. Once you’ve found that spot, place the subwoofer there. If you only have a few choices for postions, stand in each of these and work out which is best.
Work through any settings you have on your cinema amp. Use the automatic calibration system (if it has one) to get a rough idea of how the room should be set up. Repeat the process a couple of times to ensure the amp didn’t get confused the first time. You often need to set the size of the speakers on the amp. Generally speaking, if you have a subwoofer, set the speaker size to small no matter how large the speakers.
Use your tape measure to confirm the distance settings. This ensures the sound is arriving at your ears, at the same time, from each of the speakers. Correct any mistakes using the on-screen menus on your cinema amp. Check the levels settings - use the test tone from the cinema amp or the tones on the THX disk. The levels should be the same from each speaker.
Consider working through the rest of the DVD and exploring other aspects of sound set up. You can do plenty more on a DIY basis - more than I can cover here. Remember that there is really only one optimal position in the room to listen, so place your favorite chair there and guard it!
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Simon spent eight years in the feature film production. Upon leaving the industry he formed Beyond the Invisible in London UK which specializes in high end whole house entertainment systems, home theaters and lighting control and currently has a staff on ten. He is a certified CEDIA designer and avid collector of Citroen automobiles.