Spectrogram questions

[larryweiner]

I'm really new to Audacity and have recommended it to friend (in Bulgaria ... I'm from the USA) for use in re-mastering some old 78 rpm records. Actually I usually use a combination of SoundForge and iZotope RX to do most of remastering... so I'm writing from that perspective.

I was looking at the Spectrogram features built into Audacity and was hoping to see something comparable to what is in iZotope Rx3 (advanced).... but can't seem to find it. Perhaps there is a plug-in that will work or maybe I just haven't looked at the correct place in Audacity.

What I'd like to see is some kind of representation so that it would be easy to detect (see) 50 Hz hum (and its harmonics). Does anyone know of such a thing in Audacity. I'm also uploading a snapshot of Rx3 Screen showing both the wave form and the waveform/Spectrogram opacity and superimposed on that is the Spectrum analyzer for the record leadin. You can see the very pronounced 50, 100, 150, etc bands on the spectrogram.

[steve]

I was looking at the Spectrogram features built into Audacity

I presume that you mean "Plot Spectrum" http://manual.audacityteam.org/o/man/plot_spectrum.html

and was hoping to see something comparable to what is in iZotope Rx3 (advanced)

Well I can see a few differences, but what in particular do you think is missing from Audacity's Plot Spectrum?

[Trebor]

What I'd like to see is some kind of representation so that it would be easy to detect (see) 50 Hz hum (and its harmonics). Does anyone know of such a thing in Audacity. I'm also uploading a snapshot of Rx3 Screen ... You can see the very pronounced 50, 100, 150, etc bands on the spectrogram.

Mains hum and harmonic "bands" do show up on the Audacity spectrogram if you adjust spectrogram settings in Audacity preferences from the default settings ...

Mains-hum "bands" appear when you increase the resolution setting (window size) of the spectrogram, ( doing this will use more CPU ).

mains-hum harmonics visible on Audacity spectrogram.gif (148.24 KiB) Viewed 1194 times

With these higher-resolution spectrogram settings Audacity uses more CPU when rendering them : depending on how fast your computer is there may be a noticeable delay when a high-resolution spectrogram is generated.

[larryweiner]

Thanks to those of you that replied - this has helped a lot. I didn't realize that there are different spectrum "presentation" in different parts on the Audacity software.

This clears things up significantly.

I there a prarituclar "tool" that can be used get rid of Hum. I experimented a bit with the Notch filer plugin and that seems to do the job. An recommendations on suggested "Q" values.

also... is there some place that gives descriptions of the plugins with suggested uses and settings?

Larry

[steve]

also... is there some place that gives descriptions of the plugins with suggested uses and settings?

See this topic: http://forum.audacityteam.org/viewtopic ... 481#p79481