[LAD] detailed spectrum for wide freq range

[fons at kokkinizita.net]

On Fri, Mar 12, 2010 at 01:32:19PM +0300, Andrew Gaydenko wrote:

> On Friday 12 March 2010 11:45:22 Raine M. Ekman wrote:
> > Have you tried Audacity? Choose Analyze->Plot Spectrum and you probably
> > get all the options you need.
> 
> It isn't detaild sufficiently. Say, if I have a signal with 10 tones at -20db 
> level (in 20Hz - 20KHz range), I'd want to see 10 appropriate peaks at -20db 
> with almost -inf db between (and harmonics and intermodulations at case this 
> signal is was going and recorded through some hardware - all chain must work 
> at 192K).

Do you want a logarithmic *scale* or a logarithmic *analyser* ?
In other words what exactly are you trying to do ? 
 
> On Friday 12 March 2010 11:49:26 Arnold Krille wrote:
> > Replace jaaa with japa in your work-flow.
> > Same author, same quality, more features and logarithmic frequency scaling.
> > And inbuilt white and pink noise generator...
> 
> It's limited in freq and scale (db) ranges.

Frequency range is limited to 20 kHz, it's meant to be
a perceptual analyser. Amplitude range in the display
is 80 dB and you can add gain. 

How accurately you can measure certain things (or if
they will be visible at all) depends on the analyser
bandwidth and the levell of its sidelobes. For Jaaa
the BW is constant over the F range, and all sidelobes
are below -80 dB (and decreasing as you move away from
the center frequency). For Japa BW is function of F and
sidelobes are below -40 dB. 

Ciao,

-- 
FA

O tu, che porte, correndo si ?
E guerra e morte !