STONES SOUND STUDIO
Setting up a home theater speaker system
Using DVD THX audio noise test
Russell Storey updated 2009
Setting up a home theater speaker system using a THX test tones (
broard band white noise) played back from the DVD player is one of the
better ways to hear not only the sound signature of each speaker tweeter
midrange and bass but also its real SPLdb (Speaker pressure Level)
level. The THX test tones are actually testing the response of the home
theater system all the way through from the DVD player via the Home theater
receiver to the speaker via the speaker leads.
Any change in the channel levels or difference the sound signature of each speaker and or phasing (reversed speaker leads) will be very easy to detect with your ears as you listen to the signal.This very simple test signal is available from any THX certified DVD movie disk see list of movies.
The THX test for Audio is accessed via the main menu on the DVD disk.
Access the THX Audio Set up in the Sub menu of
the Pearl Harbor DVD . Then when sitting in your lounge chair
facing the center speaker and screen run the test tone and the THX
noise signal will be sent to each channel starting at the front left
speaker then rotating in a clockwise motion through each of the 5.1
6.1 or 7.1 channels
finishing with the subwoofer. Repeat this test several times until you get all the channels balanced in level (a good starting point on most receivers is set the Receiver Volume to 5/10 then pre set each channel level to +7 /10 for all speakers to begin with) pre set +5/10 for the Subwoofer level .
Subwoofer Amplifier Control level Settings using THX test tone
If your receiver has a DTS subwoofer level setting menu then set this to +10 for DTS . DTS subwoofer level should be set +10db above the standard Dolby Digital level of 0db.
Initial Subwoofer Amplifier settings .
Turn "OFF -ON -AUTO switch to "ON" , "" Do not use Auto .
Pre Set your subwoofer Amplifier volume control to 12oclock and the Frequency control to 11oclock , set the phase switch set to normal
Play the THX Audio Set up from the sub menu section of the Pearl Harbor DVD and set the channel levels and Subwoofer level so that the Subwoofer level by ear so it just complements the Front speakers but is not too loud .
Switch the Subwoofer amplifier phase switch between 0degs and 180degs several times , subwoofer will sound similar and in sync to the front speakers when the phase switch in the correct postition . When the Subwoofer is out of phase the sound will be lower in level than the fronts and produce Hollow sound like its coming out of a tin can .
to be continued ............................THX certified DVD movie disk see list of movies.