Calibrating Your Center Channel Speaker
Once you’ve picked out the best center channel and properly positioned it, you still need to make sure your home theater receiver or surround sound processor is properly calibrated. Many people skip this step, as you do get sound without calibration, but getting this right can make a huge difference in the sound you get. This is getting into the menu and set up section on your home theater receiver. If you have read this far, you are probably of the DIY mindset, so just dive in!
Many modern home theater receivers now come with a microphone to allow the receiver to both auto-calibrate and in some cases to improve the sound with room equalization. Be sure the read the instructions for the microphone and follow them closely, paying special attention to where the system asks you to place the microphone. Most systems want you to have the microphone pointing towards the ceiling. We suggest you do this first, then fine-tune the results from the calibration. To learn more about calibration, check out our home theater buyers guide.
After you run the calibration, first make sure the distances the system thought it heard, are accurate. Just use a tape measure and adjust any that are off. We find many new home theater receivers are getting better at distances, except with subwoofers, those are usually off by several feet. The distances set the delay inside the home theater receiver so even if one speaker is 10 feet away and another 20 feet, the sound arrives at your ears at the same time.
Next is level calibration. There are now many good apps for smartphones that do a good job with setting levels. In the perfect world, you want to try and get all of your speakers to the same exact level. However, we see nothing wrong with having the level of the center channel speaker be 2 to 3db higher than your left and right. A lot of movies go overboard with special effects and having the center level raised just a bit will make it easier to understand the dialog. Feel free to experiment with the levels.
Our final step in the process involves listening. We are going to be changing the crossover point of the center channel speaker. You’ll see in your home theater receiver a size or crossover section under the speaker set up menu. A few receivers only give you a choice of large or small. Small is standardized to have a crossover at 80hz and unless you have a huge center channel speaker, you should choose small. If your home theater receiver has the ability to change the frequency, you’ll have some fun with the next step.
This step is more important if your center speaker is inside or on top of a cabinet. We suggest you start out at 80hz. Play a soundtrack that has deep voices in it. If any of the voices sound a little muffled, it is likely caused by some kind of cabinet resonance. Then try changing the crossover to 90 or 100hz. By raising the crossover (this is the frequency range going to the center speaker) we can usually reduce cabinet resonances that normally occur around 60-90hz. In many cases, this will make an amazing difference in the clarity of the dialog. Feel free to experiment with this and the levels until you are starting to hear the emotions of the performer's voices with minimal resonance. We do not think you should go above 110-120hz though unless the center speaker brand recommends higher.