[LAD] Calculate R M S (Alfs Kurmis)

[Fons Adriaensen]

On Fri, Feb 18, 2011 at 09:19:27PM +0000, Folderol wrote:

> > isn't a detail - it has quite a marked effect on the response.
> > Many software 'VU' meters use a first order lowpass - this doesn't
> > even come close to the response of a the real thing.
> 
> Hmmm.
> Remembering my early training... In quality moving coil test meters this was
> referred to as critical damping and not only gave the best response time but
> also gave confidence that the meter needle wasn't sticking. With dead-band
> damping where the needle slowed to a stop as it rose (or fell) you were always
> tapping the glass because you weren't *quite* sure.

Normally MC meters should be critically damped which means *no* overshoot.
But the VU was explicitly specified as underdamped. That is one of the reasons
why real VUs are not cheap: you can't use a general-purpose MC meter to make a
VU, you need one that was specifically designed for that purpose.

Ciao,

-- 
FA