This Eq curve seems to be popular and very useful for people doing voice recordings, and it certainly helps to achieve ACX compliance. Perhaps this (or a similar curve) would be a good addition to the shipped EQCurves.xml
Ideally it should be used with a long filter length, but the filter length is not currently stored in the XML. Fortunately it works quite well with the default filter length, but it performs better with a long filter length, so a second feature request is that Filter Length is added as an optional parameter to the XML definition.
What he said. The tool doesn’t just whack off everything below a certain frequency like High Pass Filter. It’s designed for steep, but gradual transition between the lowest expected valuable voice frequency and the highest expected hum pitch. That’s why there are no adjustments (except for the Length slider).
This is the exact best place for each of those equalization values.
My joke is Steve is going to become world famous not for saving someone’s life at Brighton, but for seven equalization values.
It is not yet in for Audacity 2.1.2.
The next release is supposed to be about upgrading to Wx3 rather than adding new features. As this is not related to that upgrade and is not a bug fix I’m hesitant about introducing it now, though you may want to suggest this on the QA list as a low risk enhancement that has had thorough field testing. Would there be much impact on documentation? I see one image here that would need to be updated: http://manual.audacityteam.org/o/man/equalization.html
They are similar and for similar purposes.
The main difference is that “LF rolloff for speech” is specifically designed for speech recordings (though it can of course be used with other types of material). The corner frequency is a little lower than the 100 Hz rumble, so less damage to the spoken voice, (particularly for deep voices), and somewhat steeper, so more rejection of unwanted rumble.
Ideally the “LF roll-off for speech” should be used with a long filter length, which currently requires that the user reads the manual, but even at default settings it is likely to perform slightly better for speech recordings. Hopefully we will be able to add “filter length” to the XML curve definition in a future version of Audacity.
Did we decide on a name for this curve? Perhaps “Low rolloff for speech”?
I’d like the name to include the word “speech”, as that presents the strongest clue as to what this curve is designed for (ans I think also answers Gale’s question about deciding which curve to choose).