A Guide to Bass Management (Part I)

[Big Daddy]

Originally Posted by erict

Actually I do understand #8 it's #13 that throws me So my other speakers should be dialed in at 70db manually instead of using auto setup? Not sure what YPAO does as far as reference. That's whats really confusion me. After I dial the subs in at 70db how do I know what auto setup is dialing my speakers too. One thing I do know is the speakers are all within 1-2db of each other when checking with the SPL meter but not sure where they stand with the subs at 70db. After running auto setup does it bring the sub level in line with the speakers? Another words, when I run the test tones on my receiver I can't remember if it is a set volume or if I am able to turn the volume up during test tones

#8 basically makes sure that the level of each sub is the same.

#13 is about the combined output of the two subs with respect to the other speakers. That is what calibration programs such as Audyssey or YPAO do. They adjust the level of these speakers by turning their levels up or down. When they adjust the sub level, that adjustment affects both subwoofers and not the individual subwoofer. This way, the combined level of both subs will match the other speakers.

Even after running YPAO, it is not a bad idea to double check the level of the speakers and the combined subwoofes. Do not adjust anything on the back of the subwoofers. When you run test tones through the other speakers, you will notice that the SPL meter is fairly stable. However, when you get to the subwoofers, you will notice that it varies a little. These long wavelengths of bass frequencies like to play a game with you. That is why I suggested to move the SPL meter a little to the left and right and average the readings.

The generally accepted calibration level for home audio is 75dB, but you are free to set your speakers higher or lower. You are also free to increase or decrease the level of your subwoofers with respect to the speakers. Make sure you do all the adjustments in the receiver and not on the back of the subwoofers.