What You Need
To calibrate your system you'll need 2 handy little items. A RadioShack SPL meter, and a home theater calibration DVD. The SPL meter is the device used to measure sound. This allows you to compare the sound level of your speakers and calibrate their levels to match. The analog version is the best one to go with, as it measures more minute increments and runs about only $35. "Video Essentials" and "Avia: Guide to Home Theater" are home theater calibration DVDs that usually run about $40. You'll use the DVD to play a series of test tones which you will use to measure the sound level of your speakers. With these DVDs you'll also get in-depth tutorials on audio and video calibration.

You can use test tones produced by your receiver or processor, but they are not as accurate since the test tones aren't coming from the component you're going to be playing audio from (the DVD player). Using your receiver's test tones for calibration doesn't account for the affects the DVD player and the connecting cables have on the audio signal.

The calibration DVDs offer tutorials on why you should calibrate, and the purpose behind it all. You won't get a full tutorial of speaker calibration on this web site simply because these DVDs are the perfect resource for any home theater enthusiast.

Hints and Tips
Before calibrating your speakers you should set your bass and treble controls to zero. You don't want these controls maxed so your receiver/amp has some breathing room during loud audio segments. When listening at high sound levels you run a good risk of pushing your amps beyond their limit causing amplifier distortion or "clipping". All distortion is bad, but clipping is one of the worst kind. The amps signal is uncontrolled when it's clipping which can lead to speaker damage.

The best rule of thumb is to never set your tonal controls above half. Which usually means having the knob marker point at 3 o'clock. The best bet is setting tone controls to zero. At first your system may sound dull, but after you get used to this setting you'll realize the sound is actually smoother and more accurate than the bright and grating sound most people listen too. After a short while you wonder why you ever liked the old grating sound settings.

During the test tone sequence of the DVDs you'll need to keep your DVD remote handy so you can flip back to the beginning and retest the audio signals to get your speakers balanced. It should only take 2-3 three times to go through the speaker test tones to get all of your speakers balanced and working together.

How Often
If your speakers are new, they are going to go through a break-in period wherein the drivers loosen as you play them more often. Once your speakers break-in, the sound they emit will be very different from the sound you heard right out of the box. Some speakers take only a week of good play to break-in while others can take about 2 months to fully break-in. It is for that reason, within the first couple months of owning your new speakers, you'll need to calibrate them multiple times. Whether you decide to check every 2 weeks or every month is up to you, but you should recheck the sound levels within 3-months. After that, you shouldn't need to re-calibrate your speakers for another 6 months to a year or after any power outages.

After your subwoofer fully breaks-in you may find that the bass response has changed so much that it no longer sounds the way it did before. You may need to move the sub to a new location after it breaks-in to get the bass response the way you want it. (See placement for more info)

Break The Rules (It's Your System)
After getting your speakers properly calibrated you should notice a huge difference in how all your speakers blend together to produce a nice envelope of sound. However, you may find some aspects of the sound not to your liking. It's usually the surrounds and subwoofer levels in debate.

Try living with the surrounds properly calibrated before changing them. Most people prefer their surrounds louder since they want to emphasize the fact they actually have surround sound, but after a while this desire fades and the enjoyment of the system as a whole brings far greater satisfaction with more accurate sound. If you still desire to turn up the surrounds after living with them don't hesitate to do so. In the end it's your system, and it should play the way you want to hear it.

After calibration you may find that that the sub has been calibrated too low for your taste. Raise the sub to a level that you like if you want more bass. It's hard to calibrate bass blindly. You run the risk of turning it up too much, producing bass that doesn't blend well with the other speakers and draws attention to itself.

If your listening to music and you find yourself glancing at the sub when it kicks in, you most likely have the sub up to high. The only way to calibrate your sub correctly is to start from the calibration point, and slightly turn it up followed by a quick test. It's shouldn't take to long to get it right, and you'll eventually find the level that's right for you. Again it's personal preference how you want your sub to sound. Speaker calibration gets your speakers to work together in perfect unison, and that's always a good place to start before tweaking the system to your tastes.

Special Cases
Some systems do not allow for the independent calibration of the main speakers and the surrounds and instead rely on balance controls. You will need to fiddle with the balance to get the main speakers to the same level before moving on to the other speakers. Surround speakers that can can't be independently calibrated may need to be physically moved to the right spot to create the perfect sound field.