13 Feb
2010
13 Feb
'10
7:28 p.m.
On Sun, 14 Feb 2010 00:00:23 +0100
fons(a)kokkinizita.net wrote:
On Sat, Feb 13, 2010 at 05:37:50PM -0500, Monty
Montgomery wrote:
Does anyone know where they got that figure of 2122Hz from? It's always
puzzled me. Is there some arcane mathematical significance, or was it
the work of an engineer with an hangover?
--
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.
The RIAA preemphasis is not a biorthogonal
filter. There will always
be at a minimum some phase/group delay as the 'perfect' inverse filter
is unstable. You can only approximate it. Another example of an
analog horror we no longer need to put up with in the digital era :-)
The RIAA filter applied (normally) in the cutter is
(in Bode-plot form)
+6dB/oct up to 50 Hz
flat up to 500 Hz
+6dB/oct up to 2122 Hz
flat above that