“Home Theatre” Audio Calibration

A Review by: Alphonso Soosay

calibrate-home-theaterIf you examine your 5.1 or 7.1 AV receiver that you purchased you will notice on the remote control that there is a button called “Menu”. Press the menu and look for “Set-up” in the menu. This is where you start programming your home theatre speaker system calibration.

However if you have not done or discovered these room calibration options on your remote control then chances are that your Home Theatre surround sound could be almost certainly out of balance. This balance is very important because after the room calibration is done, your home theatre effects will sound as close to your local “Cinema Theatre”. The calibrated smoothness of surround sound is really pleasurable and that’s why it is called: Home Theatre”. These are just examples of various AV receivers programming requirements.

Speaker Configuration: Is all about Inputting the combination of your multi-speakers into your receivers system and also their corresponding speaker size (small for regular and mini speakers, Large for two-way full size speakers) to automatically set the composition of the signals output  from the speakers  and its frequency response.

Surround Speaker’s Settings: Take advantage of this function when using multiple surround speakers’ combinations for a more vital surround sound. Once the combination of your surround speakers to be used for the different surround modes are preset in your system, only then the surround speakers will be selected automatically according to your surround mode requirements.

Crossover Frequency: Set the frequency (80/100/120 Hz) in which the deep Bass sound of the various speakers is to be output from the subwoofer only. Tick Subwoofer Mode, This selects the subwoofer speaker for playing back deep Sub-Bass signals.

Subwoofer Peak Limit Level: This is a restriction for detecting the maximum level of low Bass signals output from the subwoofer channel in order to protect the subwoofer from damage and unpleasant distorted from being produced.

Delay Time: This control is for optimizing the timing with which the audio signals are produced from the speakers and subwoofer according to the listener’s position.

Channel Level: It adjusts the volume of the signals output from the different speakers and subwoofer for the different channels in order to obtain optimum balanced surround effects.

Surround Back Speakers:  When using two surround back speakers, set the distance of the two speakers.

Digital In Assignment: This assigns the Digital input connections from the different input sources. (Input Source: Blu-Ray, DVD, CD Set Top Box. Digital Inputs: Coaxial, Optical)

Video Input Mode:  Set the input signal to be output from the monitor output terminal.

Audio Delay: Adjust the time delay of the video and audio signals.

Set-up Lock: This setting is the option for you to lock or not to lock the system Set-up settings. If you lock it then it cannot be changed. If it’s unlocked then chances are that accidents can happen and room calibrations can go out of sync.

The Programming: The first stage on various AV receivers is: select “Speaker Size” Large, Small, or none, for the Left and Right front speakers, the Centre speaker, and the Surround speakers. Speakers with 6-inch or bigger woofers are considered large. The next step is to use a tape measure and measure from the sweet spot to all the 5.1 or 7.1 set of speaker distances. Input all 5.1 or 7.1 speaker distances onto the menu data. It’s only then that the receiver will make sure that the sound from all your speakers reaches your ears at exactly the same time at where you are seated. AV receivers might require you to input that information as milliseconds rather than feet or meters, just remember that 1ms is the equivalent of one foot. Ultimately, you are required to make sure that all of the speakers are equal in distance level by using the receiver test tone to each speaker one by one, which will help you adjust the relative volume of each channel. As the test tone sound moves from one speaker to another speaker, you have to make sure that the loudness of each speaker should stay at the same volume (85dB). You must adjust the level (volume) of each speaker by using your speaker setup menu controls and checking it with a sound level meter which will ensure more precise level performmance operations. Or use your “Ear” if you don’t have the sound level meter option.  Other further options are to purchase the DVD “Home Theatre Tune-Up” from Sound & Vision. There are additional Calibration tests to be discovered which you will find very interesting.

Previous to Speaker Calibration requirements are: Make sure that all your front speakers are matched with the same brand or same overall frequency response. If you are using different brand of speakers for front Right / Left and Centre then consider upgrading by moving up to a matched package. Even a moderately priced matched speaker brand will offer far more consistent sound in terms of frequency response.

Confirm that all your speakers and source interconnect cables are in the correct input location:  Optimize your speaker placement, if for any reason you are unable to make use of speaker stands or brackets, just remember that’s it’s important to position the front speakers with their tweeters aiming at your ear level. The Left / Right speakers should be equidistant from the listening position. Place Left and Right speaker within 12 inches of a room’s corner wall angle it away from the corner and aim toward the focal listener’s position.

Note: using speakers out of bookcases and placing them on floor stands or using wall brackets can radically improve your speaker system sound quality. Make use of quality speaker and interconnect cables: Avoid using tinny, freebie cables that come with your DVD packing. Step up to higher-end cables as it will make a remarkable improvement to your sound. It actually adds more presence to your listening sound.

Acoustic Issues: Rooms with acoustic problems are where polished wood or tile floors and lots of windows or mirrors always will sound excessively bright and reflective; using a solid carpet and window drapes will soak up more or less of the deflective problems.  If you have a large living or family room and your kind of music requires pumping up the volume, then you may need more RMS power. You can add a separate and more power amplifier to your existing system. Have a look in your receiver’s owner’s manual or back panel of your receiver to see if it has a set of preamp-outputs for the Left, the Right, the Centre, the Left-surround, and the Right-surround channels. If your current receiver is equipped, then you can go ahead and hook up a high powered amplifier of 150 to 200-watt-per-channel to your receiver. This is where you will enjoy the feel and the punch of the music.

Having unwanted Boom-ness or unevenness with your Subwoofer speaker? Okay must fine-tune your subwoofer level and crossover controls, before you do anything else try moving your subwoofer out of the corner and place it closer to one of the front speakers, it will produce a change of sound with smoother and flatter bass. If the problem still exists, then try lowering Subwoofer level (volume) control. A recurrent problem is that certain people crank their Sub’s louder than necessary. So if you are using small satellite speakers, the crossover control should also be set to its midpoint or higher range. Two-way bookshelf speakers produce more bass on their own, so they sound best with the sub’s crossover knob set at the bottom of its range. You will have to experiment with crossover settings for your speakers requirement in your room until you hear and feel the correct balance required.

Alphonso Soosay / 2006

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