Re: free Orban loudness meter app now available

In article <48012768.313050937@[EMAIL PROTECTED]
>, 
nospam@[EMAIL PROTECTED]
 says...
>
>
>On Sat, 12 Apr 2008 11:41:58 -0800, Robert Orban
><donotreply@[EMAIL PROTECTED]
> wrote:
>
>>In article <48008557.271561968@[EMAIL PROTECTED]
>, 
>>nospam@[EMAIL PROTECTED]
 says...
>>>
>>>
>>>On Fri, 11 Apr 2008 11:33:40 -0800, Robert Orban
>>><donotreply@[EMAIL PROTECTED]
> wrote:
>>>
>>>>In article <48004342.189109968@[EMAIL PROTECTED]
>, 
>>>>nospam@[EMAIL PROTECTED]
 says...
>>>>>
>>>>>
>>>>>On Fri, 11 Apr 2008 06:52:15 -0400, "Arny Krueger" 
>>>><arnyk@[EMAIL PROTECTED]
>
>>>>>wrote:
>>>>>
>>>>>>"Robert Orban" <donotreply@[EMAIL PROTECTED]
> wrote in 
>>message
>>>>>>news:20080411-033616.328.0@[EMAIL PROTECTED]
>>>>west.giganews.com
>>>>>>
>>>>>>> The software accepts two-channel stereo inputs. The VU
>>>>>>> and PPM meters are split to indicate the left and right
>>>>>>> channels. The PPM meter also displays the instantaneous
>>>>>>> peak values of the L and R digital samples.
>>>>>>
>>>>>>When I started the program, the Vu and PPM meters started 
>>reading 
>>>>mid-scale 
>>>>>>and full-scale respectively, with no music playing. This seems 
>>>>>>counter-intuitive. 
>>>>>>
>>>>>
>>>>>Works as expected for me. my only issue is that the PPM isn't 
>>scaled
>>>>>as a normal PPM.
>>>>
>>>>I spent some time soul-searching about the issue of scales and 
>>finally 
>>>>chose to put all of the meters on identical scales to make it easier 
>>for 
>>>>users to compare the meters.  In future version, we may make 
>>scales a 
>>>>user-definable parameter.
>>>>
>>>>Bob Orban
>>>
>>>Can you explain a little more about the variable gain/sensitivity
>>>controls available for a couple of the scales? I'm not really too 
sure
>>>how one should be using those.
>>
>>Because the scales are all -30 to 0 dBfs, setup is really somewhat 
>>arbitrary. If you set the VU Gain to +10 dB, the VU meter will 
indicate 
>>the same as the peak meter on a sinewave. (We sill probably 
change 
>>this is the next revision so that that this will happen with the VU 
Gain 
>>set to 0.)
>>
>>As for the CBS loudness meter, there was never an "official" 
>>calibration published. As stated in the readme, if I want to compare 
it 
>>with the BS.1770 meter, I set the CBS gain to +7 dB if I want to 
>>compare the peak excursions of the meter wit BS.1770 and to +10 if 
I 
>>want to compare the experimental long-term CBS loudness to 
BS.1770.
>>
>
>OK. here is what I get.
>
>Generate a tone at -18dB in Audition, and it shows -14dB on both 
VU
>and PPM, with VU gain set to 10dB. Is that what you would expect?

I would expect a sinewave peaking at 0 dBfs to indicate 0 on the 
loudness meter's PPM and absolute peak meter. I would also expect 
the VU meter to read 0 dB when its gain is set for +10 dB. Because 
this is admittedly confusing, the next release will be modified so that 
when the VU gain is set to 0 dB, the VU meter agrees with the 
PPM and absolute peak when fed with a sinewave.

>
>BS 1770 also shows roughly -14dB, and I can make CBS match that if 
I
>wind its gain up to 18dB.
>
>I am going to try some loudness testing later. I will choose several
>different music types and change their amplitudes until they are
>subjectively as loud as each other. Then I will see how the CBS and
>BS.1770 respond. I presume the tell-tale left behind by the CBS is
>roughly equivalent to the main bar of the BS1770?

There are two hold bars in the CBS. One jut holds the peak indication 
of the meter, while the other (the cyan bar) is an experimental long-
term loudness measurement. Please see the readme for details.

The experimental long-term loudness indication still can get fooled by 
certain types of program material, so I expect I will refine the algorithm

further in future releases.