Need help calibrating your home theater system? Well, there's an app for that!
Theater Tool uses the built in microphone on your iPhone or iPod Touch to help you set the relative volumes of the speakers in your home theater setup. Many home theater "Receivers" have a speaker calibration mode that puts out a sound from each of the speakers individually going around the room. The idea is that you then sit in your "listening spot" and adjust the relative volumes of the different speakers so they all sound the same. Of course if your listening spot is closer to the rear speakers they will sound too loud, or if your room is off center all of the sound from one side would constantly be louder than the rest of the room. The biggest problem with adjusting the speakers is that your hearing is not really a good judge of how loud a sound is, after a while it is difficult to tell if you need a speaker louder or softer. Additionally some home theater systems have a delay adjustment to compensate for the time sound takes to travel across a room, this adjustment is also subject to hearing or you could look up the speed of sound and do a calculation of the actual time.
This is where Theater Tool comes in handy, it has two simple tools to assist you in this process, a sound meter with a "lock" for your main speaker and a delay time calculator. The built in instructions tell you to set your speakers at a normal listening level and engage the speaker test/calibration mode. Once in this calibration mode the speakers will output a loud hiss (white or pink noise) that will travel around the room. When the main speaker is putting out the sound, press the lock button, this is the level that all other speakers will be compared to for the rest of the rest. Depending on the design of the receiver you either wait for it to cycle to the next speaker, or press a button to move on to the next speaker. At this point you look at the meter on the screen to either turn up or down the volume on that speaker. Do this with all of the speakers in your system. Some receivers allow you to enter the delay time from the front to the rear speakers. The built in distance to time calculator allows you to do this quickly, and it operates in both English and metric units. Of course if you re-arrange your room, or reset your receiver you will need to do this again.
This application is very straightforward and if your receiver has these controls it is very handy to use. The "lock" feature is what distinguishes it from the VU meter in the recording application, but if you set the volume of your system to indicate 0dB on the recorder then you could use that as a reference. The built in calculator for distance is handy as well, but could be looked up on the web.
All in all I would say that this app is great if you are the guy that goes to your friend's house and calibrates their stereo for them and would use it more than once. However if you are a professional you would already have high end gear to do this job, or if you just want to calibrate your own home stereo this will do the job but there are free alternatives (albeit harder) out there. 4 of 5 stars!
Name: Theater tool