Video and Audio Center Blog



Thursday, March 31, 2016

CALIBRATING YOUR HOME THEATER AUDIO


Everybody knows that you need to have the speakers of your home theater connected to an AV Receiver, regardless of whether it was purchased separately or that it came with the speakers as an all-in-one product. It’s also pretty much understood that you put the Left front speaker and the Right front speaker (so as to have stereo) and the center speaker (a.k.a., center channel) between them. That leaves the two surround speakers (Left and Right) which need to go as their name implies on either side of the room near the back so that they’re even with where the people who are going to be watching are sitting (i.e., on a couch or lounging chairs, etc.).  As far as the subwoofer goes there’s no worries — that’s because, unlike the other speakers, a subwoofer’s sound is omnidirectional and so it can be placed near a wall or behind a couch, etc. without concern. And as far as where the people are sitting, that is dictated by where the TV is — and you can bet a BIG SCREEN TV will get a lot of people to watch. That also dictates where the speakers will be placed relative to the TV and to the people.



But what’s not so obvious is that all of these speakers need to be calibrated against each other so that their sound blends together as necessary (for example, when there’s dialogue) or steps back to let surround effects take over (for example, when there’s an explosion in the movie).  You can’t just turn the volume up or down because that affects all the speakers together; what’s needed is to calibrate the speakers to each other and to the room they are playing in. This will not only take care of the problem but will also tailor the sound to the particular environment — your home — so as to make it more suitable for you.

DOING THE CALIBRATION AUTOMATICALLY

The basis for this is for the audio receiver to put out a series of pulses/sounds from each speaker and so adjust the individual audio streams based on their location to those who are listening. Modern AV Receivers have this calibration system built in. All you have to do (besides follow the instructions provided on the receiver’s faceplate or on the TV if the receiver has a connected interface to view) is place the included microphone at the listening position (i.e., your favorite seat on the couch, etc.), plug it into the receiver and activate the system. To do it properly it’s important that any surface sounds be eliminated, so if the street outside is particularly noisy or the nearby refrigerator or microwave is making a din, just wait a bit before going ahead. You turn on the system and leave the area and come back when it’s done (i.e., it’s quiet). Then you watch as the AV Receiver takes care of all the calculations and processes and just has you accepting a few decisions it’s made (or you tweaking them if you prefer). That’s it.

DOING THE CALIBRATION MANUALLY

On the chance that you just like to do things yourself because you don’t think much of somebody else’s idea of how digital tech should work — then doing the calibration yourself is the answer. You’ll need a sound pressure level meter (SPL) and a small tripod that you can place it on. The procedure is a bit too involved to go into here; the basic steps are to first place the speakers in the correct position in the viewing area, set the receiver as to the size of the speakers and to put out the tones (pink noise, is what it is called) moving clockwise around the speakers. You’ll use the meter to adjust the levels of each speaker as well as the subwoofer. There are audio discs that will “talk” you through this and they are commercial available and not expensive either. The main thing is to read up on doing this based on your system and speaker set (check the receiver’s manual too) and then take your time. Of course if you have a professional installation done to place your speakers for you (for example, using the services of a company like Just One Touch), then all this will be taken care of as a matter of course.

Calibration your home theater’s audio is the best thing you can do for yourself when it comes to the sound that you’ll be hearing.

0 comments:

Post a Comment