Difference between revisions of "Default EQCurves"

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(re Inverse RIAA)
(roll-off gets hyphenated for 2.3.0)
 
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Here is a starting point for a default list of curves.  This forms part of a [[Proposal Import/Export Eq Curves|Proposal for Import and Export of Equalization curves]]. Note that I have added some attributes to the 'curve'; these are not decided on yet.
+
This is a 'proposal' page for a default list of curves.  It started as part of a [[Proposal Import/Export Eq Curves|Proposal for Import and Export of Equalization curves]]. It is now where we are catagorising ideas and firming up proposals.
  
You should be able to copy-paste the curves in the box below into EQCurves.xml and have them appear next time you open 'Effect->Equalization...'.
+
You should be able to copy-paste the curves in the boxes below into your EQCurves.xml and have them appear next time you open 'Effect->Equalization...'.  Alternatively load the [http://dl.dropbox.com/u/1327769/EQCurves.xml proposed default curve], which may have been updated (but does not always follow this page).
  
The following curves have been suggested (only the ones marked in <font color="green">green</font> are actually in the current [http://dl.dropbox.com/u/1327769/EQCurves.xml proposed default curve].
+
Also see [https://forum.audacityteam.org/viewtopic.php?f=28&t=33824 Submit your EQ Curves] on the Forum for some possible curves for consideration. 
 +
<h2>Probably 'in'</h2>
 +
* AM Radio
 +
'''MJS''' Replacement 'AM Radio' curve.  Cutoffs at 50Hz and 4.5kHz, 8th-order roll-off. Limited number of points to make editing easier should a user not like it.
 +
<pre>
 +
<curve name="AM Radio">
 +
<point f="20.000" d="-63.670"/>
 +
<point f="31.000" d="-33.219"/>
 +
<point f="50.000" d="-3.010"/>
 +
<point f="63.000" d="-0.106"/>
 +
<point f="100.000" d="0.000"/>
 +
<point f="2500.000" d="0.000"/>
 +
<point f="4000.000" d="-0.614"/>
 +
<point f="5000" d="-8.059"/>
 +
<point f="8000" d="-39.981"/>
 +
<point f="20000.000" d="-103.651"/>
 +
<point f="48000.000" d="-164.485"/>
 +
</curve>
 +
</pre>
 +
* Telephone - 300Hz-3.8kHz, 4th Order roll-offs.  Done from a spreadsheet.
 +
<pre>
 +
    <curve name="Telephone">
 +
        <point f="20.000000000000" d="-94.087000000000"/>
 +
        <point f="200.000000000000" d="-14.254000000000"/>
 +
        <point f="250.000000000000" d="-7.243000000000"/>
 +
        <point f="315.000000000000" d="-2.245000000000"/>
 +
        <point f="400.000000000000" d="-0.414000000000"/>
 +
        <point f="500.000000000000" d="0.000000000000"/>
 +
        <point f="2500.000000000000" d="0.000000000000"/>
 +
        <point f="3150.000000000000" d="-0.874000000000"/>
 +
        <point f="4000.000000000000" d="-3.992000000000"/>
 +
        <point f="5000.000000000000" d="-9.993000000000"/>
 +
        <point f="48000.000000000000" d="-88.117000000000"/>
 +
    </curve>
 +
</pre>
 +
* Walkie-talkie
 +
An easily-edited starting point for a 'walkie-talkie' sound
 +
<pre>
 +
    <curve name="Walkie-talkie">
 +
        <point f="100.000000000000" d="-120.000000000000"/>
 +
        <point f="101.000000000000" d="0.000000000000"/>
 +
        <point f="2000.000000000000" d="0.000000000000"/>
 +
        <point f="2001.000000000000" d="-120.000000000000"/>
 +
    </curve>
 +
</pre>
 +
* 100Hz Rumble
 +
from Koz https://forum.audacityteam.org/viewtopic.php?f=28&t=33824#p90963).
 +
'''MJS''' I like this as it has a reference and I can see the use.  Why shelve at -40-odd dB though?  Why not go all the way down?  I suggest removing the first 4 points and replacing with
 +
<point f="20.0" d="-80.0"/>. (I've done that in the current [http://dl.dropbox.com/u/1327769/EQCurves.xml proposed default curve] but am willing to change it back if there is a good reason for it.)
 +
<pre>
 +
    <curve name="100Hz Rumble">
 +
        <point f="25.558066373145" d="-40.000000000000"/>
 +
        <point f="31.632604280524" d="-39.353843688965"/>
 +
        <point f="37.316881063924" d="-37.953842163086"/>
 +
        <point f="42.635296659786" d="-36.230766296387"/>
 +
        <point f="49.237316986327" d="-33.107692718506"/>
 +
        <point f="54.196034330446" d="-29.553844451904"/>
 +
        <point f="88.033573501041" d="-6.923076629639"/>
 +
        <point f="95.871851182279" d="-4.523078918457"/>
 +
        <point f="108.957037410504" d="-1.938461303711"/>
 +
        <point f="123.828171198057" d="-0.738462448120"/>
 +
        <point f="149.228077614658" d="-0.092308044434"/>
 +
    </curve>
 +
</pre>
 +
* loudness
 +
  Paste here
 +
* RIAA
 +
'''Gale:''' This one is essential.
 +
'''MJS:''' Agreed, but lets get it right.  This is at 1/3rd octave intervals.
 +
<pre>
 +
<curve name="RIAA">
 +
<point f="20.000" d="19.274"/>
 +
<point f="25.000" d="18.954"/>
 +
<point f="31.000" d="18.516"/>
 +
<point f="40.000" d="17.792"/>
 +
<point f="50.000" d="16.946"/>
 +
<point f="63.000" d="15.852"/>
 +
<point f="80.000" d="14.506"/>
 +
<point f="100.000" d="13.088"/>
 +
<point f="125.000" d="11.563"/>
 +
<point f="160.000" d="9.809"/>
 +
<point f="200.000" d="8.219"/>
 +
<point f="250.000" d="6.677"/>
 +
<point f="315.000" d="5.179"/>
 +
<point f="400.000" d="3.784"/>
 +
<point f="500.000" d="2.648"/>
 +
<point f="630.000" d="1.642"/>
 +
<point f="800.000" d="0.751"/>
 +
<point f="1000.000" d="0.000"/>
 +
<point f="1250.000" d="-0.744"/>
 +
<point f="1600.000" d="-1.643"/>
 +
<point f="2000.000" d="-2.589"/>
 +
<point f="2500.000" d="-3.700"/>
 +
<point f="3150.000" d="-5.038"/>
 +
<point f="4000.000" d="-6.605"/>
 +
<point f="5000.000" d="-8.210"/>
 +
<point f="6300.000" d="-9.980"/>
 +
<point f="8000.000" d="-11.894"/>
 +
<point f="10000.000" d="-13.734"/>
 +
<point f="12500.000" d="-15.609"/>
 +
<point f="16000.000" d="-17.708"/>
 +
<point f="20000.000" d="-19.620"/>
 +
<point f="25000.000" d="-21.542"/>
 +
<point f="48000.000" d="-27.187"/>
 +
</curve>
  
Also see [http://forum.audacityteam.org/viewtopic.php?f=28&t=33824 Submit your EQ Curves] on the Forum for some possible curves for consideration.
+
</pre>
 
+
<h3>'Generic' boost/cut curves</h3>
+
'''MJS:''' Just give users an idea of what these might look like.  We don't have agreed definitions of 'boost' or 'cut' or 'treble' of 'bass' so give easily-modified (few points) prototypes?<br>
* <font color="green">60 Hz notch</font> - '''Gale:''' We are going to distribute notch.ny with Audacity which can cut a much deeper notch, so we probably don't need this. Additional parameters have been proposed for this (curve length="8192" category="default" draw="yes" log="yes") but filter length can't be set this way yet.       
+
'''BW:''' The bass and treble boost are good - as you say, generic and easily modified. I think the cut versions should be the inverse of the boosts.<br>
 +
'''MJS:''' I did it like this to indicate that big cuts are 'safer' than big boosts, clipping-wise.  Not a big lesson but just to give users an indication of what they might like to sensibly do.<br>
 +
'''BW:''' I think of these as the equivalent of the "tone" controls on a stereo. The effect of the cut curves as presented could just as easily be achieved with the Low Pass and High Pass Filter effects, with less fiddling.<br>
 +
'''MJS:''' True the LPF and HPF are probably better done with the nyquist effects, and I'm guessing that these are IIR filters that more accuratly match 'real' filters in amps.  EQ allows a much greater degree of control though, and users should use it if they need that.  An education issue that should somehow be addressed.
 +
* Bass Boost
 +
<pre>
 +
    <curve name="Bass Boost">
 +
        <point f="100.000000000000" d="9.000000000000"/>
 +
        <point f="500.000000000000" d="0.000000000000"/>
 +
    </curve>
 +
</pre>
 +
* Bass Cut
 +
<pre>
 +
<curve name="Bass Cut">
 +
<point f="150.000000000000" d="-50.000000000000"/>
 +
<point f="300.000000000000" d="0.000000000000"/>
 +
</curve>
 +
</pre>
 +
* Treble Boost
 +
<pre>
 +
<curve name="Treble Boost">
 +
<point f="4000.000000000000" d="0.000000000000"/>
 +
<point f="5000.000000000000" d="9.000000000000"/>
 +
</curve>
 +
</pre>
 +
* Treble Cut
 +
<pre>
 +
<curve name="Treble Cut">
 +
<point f="6000.000000000000" d="0.000000000000"/>
 +
<point f="10000.000000000000" d="-110.000000000000"/>
 +
</curve>
 +
</pre>
 +
<h2>Proposals, undiscussed here</h2>
 +
* others that should be in the default list
 +
<pre>
 +
  Paste here
 +
</pre>
 +
* rumble filter
 +
'''MJS:''' Do we need this in addition to '100Hz Rumble'?
 +
<pre>
 +
  Paste here
 +
</pre>
 +
<hr />
 +
<h2>Proposed and under discussion</h2>
 +
* 60 Hz notch - '''Gale:''' We are going to distribute notch.ny with Audacity which can cut a much deeper notch, so we probably don't need this. Additional parameters have been proposed for this (curve length="8192" category="default" draw="yes" log="yes") but filter length can't be set this way yet.       
 
<pre>
 
<pre>
 
<curve name="60Hz notch">
 
<curve name="60Hz notch">
Line 16: Line 164:
 
</curve>
 
</curve>
 
</pre>
 
</pre>
* <font color="green">acoustic</font> - generic acoustic 78 rpm curve. In reality there are [http://wiki.audacityteam.org/wiki/78rpm_playback_curves hundreds of 78 rpm curves].
+
<h2>Probably out</h2>
 +
* acoustic - '''Gale:''' generic acoustic 78 rpm curve. In reality there are [https://wiki.audacityteam.org/wiki/78rpm_playback_curves hundreds of 78 rpm curves].
 
* '''MJS:''' Who says 'acoustic' is a 'generic acoustic 78 rpm curve'?  I've never seen that before.  I always wondered what it was!  It looks very crude and not very useful to me.
 
* '''MJS:''' Who says 'acoustic' is a 'generic acoustic 78 rpm curve'?  I've never seen that before.  I always wondered what it was!  It looks very crude and not very useful to me.
 +
** '''Gale:''' Good job you queried it. I'm sure from comments I've seen before that it was "intended" as some kind of "very early" curve, but on reflection the huge cut in the lowest frequencies makes little sense. In any case from now casting around in articles on the web e.g. [http://www.shellac.org/wams/wequal.html http://www.shellac.org/wams/wequal.html] it's clear that acoustic 78 rpms were not recorded with any EQ; the idea only started in the electrical era. So I also think this curve isn't useful. 
 
<pre>
 
<pre>
 
<curve name="acoustic">
 
<curve name="acoustic">
Line 39: Line 189:
 
</curve>
 
</curve>
 
</pre>
 
</pre>
* <font color="green">amradio</font>
 
'''MJS''' Does this do a good job of simulating an am radio?  I doubt it.  I think it should be flatter in the middle (maybe 50Hz - 3.5kHz) then slope off faster above 4kHz.  It certainly needs much lower points at 20Hz and 48kHz so we don't get them 'shelves'.  Should it be simulating an 'am radio' or giving the impression of an 'am radio'?  In a play (or whatever) a lower quality (BW) may give a better 'impression'.
 
 
We have about 4.5kHz at the top end in the UK, th US has 'only' 4kHz.
 
<pre>
 
<curve name="amradio">
 
<point f="100" d="-20"/>
 
<point f="125" d="-16"/>
 
<point f="200" d="-12"/>
 
<point f="250" d="-8"/>
 
<point f="300" d="-4"/>
 
<point f="400" d="0"/>
 
<point f="1000" d="0"/>
 
<point f="2000" d="-4"/>
 
<point f="3000" d="-8"/>
 
<point f="4000" d="-12"/>
 
<point f="5000" d="-16"/>
 
<point f="6000" d="-20"/>
 
</curve>
 
</pre>
 
* bass boost
 
  Paste here
 
* bass cut
 
  Paste here
 
 
* Inverse RIAA  '''Gale:''' This is a convenience included in 1.3.12 release, but not mandatory as you can use the button to invert the RIAA curve.
 
* Inverse RIAA  '''Gale:''' This is a convenience included in 1.3.12 release, but not mandatory as you can use the button to invert the RIAA curve.
'''MJS:''' This is outdated by the improved RIAA curve below.  I suggest that it is not included in the default EQCurves for the reason given just above.
+
*'''MJS:''' This is outdated by the improved RIAA curve below.  I suggest that it is not included in the default EQCurves for the reason given just above.
 +
** '''Gale:''' Agreed it's marginal, though no doubt some would like it/may not figure you can invert the RIAA curve. I don't mind updating it against the new RIAA curve if others think we want it. If not, it can go.   
 
<pre>
 
<pre>
 
<curve name="Inverse RIAA">
 
<curve name="Inverse RIAA">
Line 97: Line 224:
 
</curve>
 
</curve>
 
</pre>
 
</pre>
* loudness
 
  Paste here
 
* RIAA  '''Gale:''' This one is essential.  '''MJS:''' Agreed, but lets get it right.  This is at 1/3rd octave intervals.
 
<pre>
 
<curve name="RIAA">
 
<point f="20.000" d="19.274"/>
 
<point f="25.000" d="18.954"/>
 
<point f="31.000" d="18.516"/>
 
<point f="40.000" d="17.792"/>
 
<point f="50.000" d="16.946"/>
 
<point f="63.000" d="15.852"/>
 
<point f="80.000" d="14.506"/>
 
<point f="100.000" d="13.088"/>
 
<point f="125.000" d="11.563"/>
 
<point f="160.000" d="9.809"/>
 
<point f="200.000" d="8.219"/>
 
<point f="250.000" d="6.677"/>
 
<point f="315.000" d="5.179"/>
 
<point f="400.000" d="3.784"/>
 
<point f="500.000" d="2.648"/>
 
<point f="630.000" d="1.642"/>
 
<point f="800.000" d="0.751"/>
 
<point f="1000.000" d="0.000"/>
 
<point f="1250.000" d="-0.744"/>
 
<point f="1600.000" d="-1.643"/>
 
<point f="2000.000" d="-2.589"/>
 
<point f="2500.000" d="-3.700"/>
 
<point f="3150.000" d="-5.038"/>
 
<point f="4000.000" d="-6.605"/>
 
<point f="5000.000" d="-8.210"/>
 
<point f="6300.000" d="-9.980"/>
 
<point f="8000.000" d="-11.894"/>
 
<point f="10000.000" d="-13.734"/>
 
<point f="12500.000" d="-15.609"/>
 
<point f="16000.000" d="-17.708"/>
 
<point f="20000.000" d="-19.620"/>
 
<point f="25000.000" d="-21.542"/>
 
<point f="48000.000" d="-27.187"/>
 
</curve>
 
 
</pre>
 
* rumble filter
 
  Paste here
 
* telephone - 300Hz-3kHz (should it be 3.8kHz?), 4th Order roll-offs.  Done from a spreadsheet.
 
'''MJS:''' This needs a point adding at 48kHz
 
<pre>
 
<curve name="Telephone">
 
<point f="20" d="-94.09"/>
 
<point f="200" d="-14.25"/>
 
<point f="250" d="-7.24"/>
 
<point f="300" d="-3.01"/>
 
<point f="400" d="-0.41"/>
 
<point f="500" d="-0.07"/>
 
<point f="1250" d="-0.004"/>
 
<point f="2000" d="-0.17"/>
 
<point f="2500" d="-0.91"/>
 
<point f="3000" d="-3.01"/>
 
<point f="4000" d="-10.41"/>
 
<point f="20000" d="-65.91"/>
 
<point f="25000" d="-73.67"/>
 
</curve>
 
</pre>
 
* treble boost
 
  Paste here
 
* treble cut
 
  Paste here
 
* others that should be in the default list
 
  Paste here
 
  
  
 
[[Category:Feature Planning]]
 
[[Category:Feature Planning]]

Latest revision as of 19:36, 3 May 2018

This is a 'proposal' page for a default list of curves. It started as part of a Proposal for Import and Export of Equalization curves. It is now where we are catagorising ideas and firming up proposals.

You should be able to copy-paste the curves in the boxes below into your EQCurves.xml and have them appear next time you open 'Effect->Equalization...'. Alternatively load the proposed default curve, which may have been updated (but does not always follow this page).

Also see Submit your EQ Curves on the Forum for some possible curves for consideration.

Probably 'in'

  • AM Radio

MJS Replacement 'AM Radio' curve. Cutoffs at 50Hz and 4.5kHz, 8th-order roll-off. Limited number of points to make editing easier should a user not like it.

	<curve name="AM Radio">
		<point f="20.000" d="-63.670"/>
		<point f="31.000" d="-33.219"/>
		<point f="50.000" d="-3.010"/>
		<point f="63.000" d="-0.106"/>
		<point f="100.000" d="0.000"/>
		<point f="2500.000" d="0.000"/>
		<point f="4000.000" d="-0.614"/>
		<point f="5000" d="-8.059"/>
		<point f="8000" d="-39.981"/>
		<point f="20000.000" d="-103.651"/>
		<point f="48000.000" d="-164.485"/>
	</curve>
  • Telephone - 300Hz-3.8kHz, 4th Order roll-offs. Done from a spreadsheet.
    <curve name="Telephone">
        <point f="20.000000000000" d="-94.087000000000"/>
        <point f="200.000000000000" d="-14.254000000000"/>
        <point f="250.000000000000" d="-7.243000000000"/>
        <point f="315.000000000000" d="-2.245000000000"/>
        <point f="400.000000000000" d="-0.414000000000"/>
        <point f="500.000000000000" d="0.000000000000"/>
        <point f="2500.000000000000" d="0.000000000000"/>
        <point f="3150.000000000000" d="-0.874000000000"/>
        <point f="4000.000000000000" d="-3.992000000000"/>
        <point f="5000.000000000000" d="-9.993000000000"/>
        <point f="48000.000000000000" d="-88.117000000000"/>
    </curve>
  • Walkie-talkie

An easily-edited starting point for a 'walkie-talkie' sound

    <curve name="Walkie-talkie">
        <point f="100.000000000000" d="-120.000000000000"/>
        <point f="101.000000000000" d="0.000000000000"/>
        <point f="2000.000000000000" d="0.000000000000"/>
        <point f="2001.000000000000" d="-120.000000000000"/>
    </curve>
  • 100Hz Rumble

from Koz https://forum.audacityteam.org/viewtopic.php?f=28&t=33824#p90963). MJS I like this as it has a reference and I can see the use. Why shelve at -40-odd dB though? Why not go all the way down? I suggest removing the first 4 points and replacing with <point f="20.0" d="-80.0"/>. (I've done that in the current proposed default curve but am willing to change it back if there is a good reason for it.)

    <curve name="100Hz Rumble">
        <point f="25.558066373145" d="-40.000000000000"/>
        <point f="31.632604280524" d="-39.353843688965"/>
        <point f="37.316881063924" d="-37.953842163086"/>
        <point f="42.635296659786" d="-36.230766296387"/>
        <point f="49.237316986327" d="-33.107692718506"/>
        <point f="54.196034330446" d="-29.553844451904"/>
        <point f="88.033573501041" d="-6.923076629639"/>
        <point f="95.871851182279" d="-4.523078918457"/>
        <point f="108.957037410504" d="-1.938461303711"/>
        <point f="123.828171198057" d="-0.738462448120"/>
        <point f="149.228077614658" d="-0.092308044434"/>
    </curve>
  • loudness
  Paste here
  • RIAA

Gale: This one is essential. MJS: Agreed, but lets get it right. This is at 1/3rd octave intervals.

	<curve name="RIAA">
		<point f="20.000" d="19.274"/>
		<point f="25.000" d="18.954"/>
		<point f="31.000" d="18.516"/>
		<point f="40.000" d="17.792"/>
		<point f="50.000" d="16.946"/>
		<point f="63.000" d="15.852"/>
		<point f="80.000" d="14.506"/>
		<point f="100.000" d="13.088"/>
		<point f="125.000" d="11.563"/>
		<point f="160.000" d="9.809"/>
		<point f="200.000" d="8.219"/>
		<point f="250.000" d="6.677"/>
		<point f="315.000" d="5.179"/>
		<point f="400.000" d="3.784"/>
		<point f="500.000" d="2.648"/>
		<point f="630.000" d="1.642"/>
		<point f="800.000" d="0.751"/>
		<point f="1000.000" d="0.000"/>
		<point f="1250.000" d="-0.744"/>
		<point f="1600.000" d="-1.643"/>
		<point f="2000.000" d="-2.589"/>
		<point f="2500.000" d="-3.700"/>
		<point f="3150.000" d="-5.038"/>
		<point f="4000.000" d="-6.605"/>
		<point f="5000.000" d="-8.210"/>
		<point f="6300.000" d="-9.980"/>
		<point f="8000.000" d="-11.894"/>
		<point f="10000.000" d="-13.734"/>
		<point f="12500.000" d="-15.609"/>
		<point f="16000.000" d="-17.708"/>
		<point f="20000.000" d="-19.620"/>
		<point f="25000.000" d="-21.542"/>
		<point f="48000.000" d="-27.187"/>
	</curve>

'Generic' boost/cut curves

MJS: Just give users an idea of what these might look like. We don't have agreed definitions of 'boost' or 'cut' or 'treble' of 'bass' so give easily-modified (few points) prototypes?
BW: The bass and treble boost are good - as you say, generic and easily modified. I think the cut versions should be the inverse of the boosts.
MJS: I did it like this to indicate that big cuts are 'safer' than big boosts, clipping-wise. Not a big lesson but just to give users an indication of what they might like to sensibly do.
BW: I think of these as the equivalent of the "tone" controls on a stereo. The effect of the cut curves as presented could just as easily be achieved with the Low Pass and High Pass Filter effects, with less fiddling.
MJS: True the LPF and HPF are probably better done with the nyquist effects, and I'm guessing that these are IIR filters that more accuratly match 'real' filters in amps. EQ allows a much greater degree of control though, and users should use it if they need that. An education issue that should somehow be addressed.

  • Bass Boost
    <curve name="Bass Boost">
        <point f="100.000000000000" d="9.000000000000"/>
        <point f="500.000000000000" d="0.000000000000"/>
    </curve>
  • Bass Cut
	<curve name="Bass Cut">
		<point f="150.000000000000" d="-50.000000000000"/>
		<point f="300.000000000000" d="0.000000000000"/>
	</curve>
  • Treble Boost
	<curve name="Treble Boost">
		<point f="4000.000000000000" d="0.000000000000"/>
		<point f="5000.000000000000" d="9.000000000000"/>
	</curve>
  • Treble Cut
	<curve name="Treble Cut">
		<point f="6000.000000000000" d="0.000000000000"/>
		<point f="10000.000000000000" d="-110.000000000000"/>
	</curve>

Proposals, undiscussed here

  • others that should be in the default list
   Paste here
  • rumble filter

MJS: Do we need this in addition to '100Hz Rumble'?

   Paste here

Proposed and under discussion

  • 60 Hz notch - Gale: We are going to distribute notch.ny with Audacity which can cut a much deeper notch, so we probably don't need this. Additional parameters have been proposed for this (curve length="8192" category="default" draw="yes" log="yes") but filter length can't be set this way yet.
	<curve name="60Hz notch">
		<point f="49.4" d="0"/>
		<point f="60" d="-120"/>
		<point f="71.3" d="0"/>
	</curve>

Probably out

  • acoustic - Gale: generic acoustic 78 rpm curve. In reality there are hundreds of 78 rpm curves.
  • MJS: Who says 'acoustic' is a 'generic acoustic 78 rpm curve'? I've never seen that before. I always wondered what it was! It looks very crude and not very useful to me.
    • Gale: Good job you queried it. I'm sure from comments I've seen before that it was "intended" as some kind of "very early" curve, but on reflection the huge cut in the lowest frequencies makes little sense. In any case from now casting around in articles on the web e.g. http://www.shellac.org/wams/wequal.html it's clear that acoustic 78 rpms were not recorded with any EQ; the idea only started in the electrical era. So I also think this curve isn't useful.
	<curve name="acoustic">
		<point f="50" d="-20"/>
		<point f="63" d="5"/>
		<point f="70" d="4.400000095367"/>
		<point f="100" d="3.299999952316"/>
		<point f="125" d="2.5"/>
		<point f="200" d="1.700000047684"/>
		<point f="250" d="0"/>
		<point f="2000" d="0"/>
		<point f="3000" d="-1.5"/>
		<point f="4000" d="-2.5"/>
		<point f="5000" d="-3.299999952316"/>
		<point f="6000" d="-4"/>
		<point f="7000" d="-4.5"/>
		<point f="8000" d="-5"/>
		<point f="9000" d="-10"/>
		<point f="10000" d="-15"/>
		<point f="15000" d="-20"/>
	</curve>
  • Inverse RIAA Gale: This is a convenience included in 1.3.12 release, but not mandatory as you can use the button to invert the RIAA curve.
  • MJS: This is outdated by the improved RIAA curve below. I suggest that it is not included in the default EQCurves for the reason given just above.
    • Gale: Agreed it's marginal, though no doubt some would like it/may not figure you can invert the RIAA curve. I don't mind updating it against the new RIAA curve if others think we want it. If not, it can go.
	<curve name="Inverse RIAA">
		<point f="30.000000000000" d="-18.600000381470"/>
		<point f="31.000000000000" d="-18.500000000000"/>
		<point f="50.000000000000" d="-16.899999618530"/>
		<point f="63.000000000000" d="-15.899999618530"/>
		<point f="70.000000000000" d="-15.300000190735"/>
		<point f="100.000000000000" d="-13.100000381470"/>
		<point f="125.000000000000" d="-11.600000381470"/>
		<point f="200.000000000000" d="-8.199999809265"/>
		<point f="250.000000000000" d="-6.699999809265"/>
		<point f="300.000000000000" d="-5.500000000000"/>
		<point f="400.000000000000" d="-3.799999952316"/>
		<point f="500.000000000000" d="-2.599999904633"/>
		<point f="600.000000000000" d="-1.799999952316"/>
		<point f="700.000000000000" d="-1.200000047684"/>
		<point f="800.000000000000" d="-0.800000011921"/>
		<point f="900.000000000000" d="-0.300000011921"/>
		<point f="1000.000000000000" d="0.000000000000"/>
		<point f="2000.000000000000" d="2.599999904633"/>
		<point f="3000.000000000000" d="4.699999809265"/>
		<point f="4000.000000000000" d="6.599999904633"/>
		<point f="5000.000000000000" d="8.199999809265"/>
		<point f="6000.000000000000" d="9.600000381470"/>
		<point f="7000.000000000000" d="10.800000190735"/>
		<point f="8000.000000000000" d="11.899999618530"/>
		<point f="9000.000000000000" d="12.899999618530"/>
		<point f="10000.000000000000" d="13.699999809265"/>
		<point f="15000.000000000000" d="17.200000762939"/>
		<point f="16000.000000000000" d="17.700000762939"/>
	</curve>