[BC] Weston VU Meters -

[cldube]

VU meter (volume unit) The term volume unit was adopted to refer to a 
special meter whose response closely related to the perceived loudness of 
the audio signal. It is a voltmeter with standardized dB calibration for 
measuring audio signal levels, and with attack and overshoot (needle 
ballistics) optimized for broadcast and sound recording. Jointly developed 
by Bell Labs, CBS and NBC, and put into use in May, 1939, VU meter 
characteristics are defined by ANSI specification "Volume Measurements of 
Electrical Speech and Program waves, " C16.5-1942 (which is know 
incorporated into IEC 60268-17). 0 VU is defined to be a level of +4 dBu for 
an applied sine wave. The VU meter has relatively slow response. It is 
driven from a full-wave averaging circuit defined to reach 99% full-scale 
deflection in 300 ms and overshoot not less than 1% and not more than 1.5%. 
Since a VU meter is optimized for perceived loudness it is not a good 
indicator of peak performance. Contrast with PPM.

http://www.rane.com/par-v.html



Chuck D (with more pertinent information this time.)

----- Original Message ----- 
From: "Barry Mishkind" <barry at oldradio.com>
To: "Broadcast Radio Mailing List" <broadcast at radiolists.net>
Sent: Thursday, November 10, 2005 2:52 PM
Subject: Re: [BC] Weston VU Meters -


> What I was reaching for was the concept of how the volume units were 
> quantified, and why with the numbers and levels that we have seen over the 
> years.
>
> As to VU, yes, I know the term Volume Units ... but were not the meters 
> originally labelled as VI ????
>