<font color='#000000'>What I posted:
I'm thinking you guys don't have a clear understanding of the acoustic principles involved here;
"Master Handbook of Acoustics" fourth Edition by F. Alton Everest, page 39 is the ANSI S1.4-1971 graph showing the frequency response of "A", "B", and "C" weighting curves on the dB response.
Yes, "C" is the flattest curve, but that is because it accounts for the Fletchur-Munson effect of our hearing ability for low frequencies and thus boosts those frequencies to flat. While the "A" weighting curve starts falling at 1kHz and is >40dB down by 30Hz.
So, this is why an "A" weighting curve with music and HT calibration tones will not work correctly.
To further expound on this premise, the leading maker of high-end calibration equipment states it this way,
THE ART OF EQUALIZATION
FOR CUSTOM HOME THEATERS By Gregory Miller, Gold Line
Gregory Miller is director of audio training for Gold Line, a leading manufacturer of audio calibration equipment. He is certified as a
Home THX dealer by Lucas film. In September, Gold Line Technical Publications will release his book "Guide to Home Theater Analysis
and Equalization." Miller can be reached at (203) 938-2588
Reprinted from CUSTOM HOME ELECTRONICS, July/August 1997
Every modern processor has a reference specification for finding "0" reference level in a test mode. Then using a sound pressure level
meter, as measured from ear level at the center listening position, the system must produce 75 dB in "C" weighting from every
loudspeaker. If you fail to do this, then speakers that are louder or softer than another in the system will produce a level that your brain
will perceive as coming from an incorrect position.
. . . . . . . . . .
Finally, changing EQ will adjust your system reference level. The last step is always to go into test mode and reset the levels, so that
every speaker produces exactly 75 dB in C weighting from the central listening position. This step is critical to proper imaging, so take a
few minutes to get the levels just right.
<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>
gene : <table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Quote </td></tr><tr><td id="QUOTE">This message was sent to: Bruce, hawke
Bruce;
Sorry, but you have it all wrong, dBC is designed for flat frequency response within 20-20kHz, dBA is weighed more like the human ear which is exactly opposite of what you said. </td></tr></table>
<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>
hawke : <table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Quote </td></tr><tr><td id="QUOTE">This message was sent to: gene, Bruce
<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>
gene : dBC is specifically designed with the Fletcher-Munson curve built-in and was designed for music.
I think we should just assume you got these flipped and end this part of the discussion.</td></tr></table></font>