Home Theater sound calibration

 Home Theater is pretty common this days in homes around the world. This can be as simple as 1 piece of sound bar to some pretty complicated multi channel surround sound. Mainly there are 2 main streams sound format, the DTS and Dolby. There are some other less popular like Auro 3D but is still about multi channel surround sound. With multiple sound mix created for movies over the years it has evolve quite far from the old days of 2 channel sound. The most common setup will be 5.1 or 7.1 although the current sound format do have multiple height or ceiling channels. Even with just 5 or 7 channels is still not that simple of getting the sound to be balance or be seamless. Many home users don't really understand on how the sound is mix or how it is intention for the listener. Challenges face by home users like example of vocal in movie is too soft, or sound effect is too much, or worst even lack of bass (LFE). I am one of those guy who faces this kind of challenges until I understand how important is for sound calibration to address those examples I have mention.

First thing when someone bought an AVR (Audio Video Receiver), looking at the manual is probably something scary. Sometimes just connecting up the cables is also a challenge. Of course, lets say you are connected up accordingly and you are ready to enjoy your movie. The next thing you notice is the sound doesn't quite right. Looking at AVR with tens of buttons and switches it can be rather overwhelming. Lucky thing is most AVR have something to help users out. It is the auto calibration function. Different company do it differently but the goal is the same, to get the sound to be right. In my case, I am using the Yamaha processor (CX-5200). This is not an AVR but a processor for the video and sound only. The main difference is the processor has no power output but AVR is all in one box. That is totally another different topic. Now in Yamaha's case it is the YPAO or like Pioneer will be MCACC or more exotic brand like Lyndoft or Arcam will be Dirac. Lets not get too far on that but each has its own way of doing the auto calibration. 

To start, auto calibration need to have some kind of instrument to do the measurement which feed information into the AVR or Processor to do the sound adjustment. There will be mic to use in case which will be provided by the manufacturer. Again different manufacturer do it differently but the basic concept is the same. Yamaha provided a 4 point stand together with the mic. The reason for this is to measure height speakers vs ground level speakers. In this picture, you can see that I have install the mic on a camera tripod. Is just makes it simple, of course can put it on anything you like. The key thing is the measurement should be at ear level on your seating position. The reason is pretty simple, you want the sound to go to your listening position on that specific height for your ear to get the sound correctly.

As the name suggest, auto calibration is pretty straight forward. Just connect the mic to the AVR than start to run the software. YPAO in this case for Yamaha which you can see on the pic. Is just something the YPAO to calibrate according to the speakers that is available. Instruction will be popping up according to the calibration as it run. Once the auto calibration is complete, it pretty much done and ready to rock and roll. 

The additional step which I was to level the individual speaker or channel. As suggested by Dolby or DTS that the reference level should be abour 75 db for each individual channel. So here I use the Umik-1 mic with the REW software as SPL (Sound Pressure Level) meter. Even more simple is to use your smart phone and install the apps. The difference of this is the measuring mic which determine how accurate the sound level. 

This is the screen in the Yamaha to adjust the level according to the SPL reading to get to 75db. This is not a must but is good to do this. The important reason for doing is to ensure the sound is all even. Doesn't matter what is the speaker or size. It should be the same level so that the sound does not over power each other. This also apply for the subwoofer. After this is done, proceed to enjoy the show.