Re: dB Gain -- was RE: FLx GN Adding Db gain

Posted by Jim Brown-10 on Nov 14, 2008; 4:47am
URL: http://elecraft.85.s1.nabble.com/FLx-GN-Adding-Db-gain-tp1330201p1497168.html

On Thu, 13 Nov 2008 23:42:37 +0000, David Woolley (E.L) wrote:

>Audio dB are weighted by frequency, so the same power at different
>frequencies will not produce a 0dB difference.

The use of weighting requires another suffix.

>It's more complex than that.  Classical music broadcasters need to
>respect dynamic range

Of course -- I oversimplified (only slightly) as an exageration of
conditions in the US. Here we have VERY few classical broadcasters.
AND -- while dynamic range must be respected, it cannot be
maintained as a copy of an actual performance because the noise
level of the listening environment is simply too high. A symphonic
performance on CD can have a dynamic range of 90 dB, but the noise
level in most homes is on the order of 50 dBA. 90 dB + 50 dBA = 140
dBA, which is 20 dB more than almost any home stereo rig. And your
car is more like 70 dBA.

73,

Jim K9YC


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