Also, even the position in your room can affect how loud a speaker sounds to your ears as the room may reinforce or take away from the perceived output level. Fortunately, all home theater AV receivers have what is called a speaker level control to balance out your speaker volume. All you have to do is turn on the receiver’s test tones, measure the levels using an SPL meter, and make adjustments up or down on each speaker until they are the same. The simplest way to do this if you don’t have a professional mic is to download an SPL Meter app to your phone. Then, run the test tones and set all of your speakers to 75db. If you have multiple subs, set your combined subwoofer level to 75db. If you have questions on how to do this, check out our subwoofer calibration video.
Speaker Distance Settings
The sound engineers who create those amazing effects in today’s movies spend a great deal of time producing a soundtrack that fills the room with immersive sound. To get this magic to occur, the sound has to get to our ears at the same time from all of the speakers. Obviously, in a typical room, almost every speaker is a different distance from our ears. The good news is, every home theater receiver also has a way to correct this. You simply measure the distance each speaker is from your main seat, put in these values, and the receiver makes the corrections to allow the sound to arrive at your ears at the same time. The one caveat here is that if you have a subwoofer that has digital processing in it that you enable through a phone app or the subwoofer control panel, then you will need to increase the distance of the subwoofer by approximately 1 foot for every millisecond of delay. If you don’t know the delay in your subwoofer, you can find it by playing an 80hz test tone (or whatever level your crossover is) and slowly increasing your distance in one-foot increments while measuring the SPL. When the subwoofer is in phase with the rest of your speakers, the SPL will hit its highest point.
Room Correction Software
The last step is to run room correction if your receiver has it. Many modern surround sound receivers have added a new feature that can actually correct for problems created by your room. Every room impacts the sound in a pretty dramatic way, reducing some frequencies and boosting others. Room correction or room equalization systems have gotten very good at eliminating a lot of these problems. Completing this step can make a HUGE difference in some rooms, but it can be a little technical for some systems. We’ve created an entire how-to guide to help you understand room EQ, it’s definitely worth checking out. We also have videos on the major room correction systems like Dirac and ARC Genesis.
So now that you know why, you are probably ready to jump in and do your first calibration. Calibrating a home theater AV receiver used to be a daunting task of menu after submenu that felt as if it required a Ph.D. in owners manual speak to get a good outcome. Today’s home theater receivers have made the process much easier, and in some cases, it's all totally automatic. Just make sure you keep the microphone you’ll get with your receiver pointing straight up as it walks you through the process. If your unit did not come with a tripod, it's a good idea to invest in an inexpensive tripod so you can get the microphone at ear level. Many will step you through the process with an easy-to-understand on-screen display.
If your system automatically adjusts everything, it's a good idea to go back into the menus and confirm everything looks and sounds okay. We’ve seen distances and crossover points be way off. Most automatic systems seem to do a decent job with the levels. It’s an easy matter to just recheck your distances with a tape measure and confirm your crossover settings are close to 80 Hz after the auto-calibration runs.