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Re: inverse loudness eq

Subject: Re: inverse loudness eq
From: "Louis Judson" inaudio
Date: Sat Mar 29, 2008 11:57 pm ((PDT))
Interesting sounds, Paul! I gather the EQ is on the second half - I have on=
ly laptop speakers at the moment... It's actually a cut if so.

2 thoughts: I think you mean "F-M" for Fletcher-Munsen, rather than Frequen=
cy Modulation's "FM" (we are engineeres here, if it is a quibble).

and, how this would be an inverse of the "loudness" curve on old hifi amps,=
 which is +10 @ 100Hz 6dB/Octave and +4 @ 10k 3 or 6 dB / Oct. (arbirary as=
 the figures might be, relating the what volume level, etc.) perhaps?

Third thing - I think we are aware of more bass in recordings because we ar=
e amplifying it over the natural level...

2c,
Lou

On Saturday, March 29, 2008, at 02:41PM, "Paul Jacobson" <=
u> wrote:
>Hi All,
>
>In a reply to an earlier email Dan Dugan mentioned the Feltcher-
>Munson loudness curve as an explanation as to why we are aware of
>more low frequency energy in recordings than which is apparent to the
>"naked" ear.
>
>I made some quick experiments at constructing an inverse differential
>FM curve last night based on a chart of FM curves. I've tried to base
>the EQ on the change of emphasis that results from a 60dB boost in
>volume.  The results appear to be quite promising and seem to sound
>closer to how I perceived  the environment when listening at normal
>levels. There is a significant amount of LF cut, however this is a
>gradual roll off to approximately -23db at 20hz rather than a steep
>filter applied at 100hz as I've used in the past. The amount of eq
>required still needs some work, but I thought I'd share the results
>of my first experiments anyway...
>
>http://www.mactrix.com.au/files/recordings/EQTest.mp3
>



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