failure to import equalization curve

Audacity 2.4.2
Microsoft Windows 10 Pro version 2004, build 19041.388

I’ve recorded a talk (audio only) in two parts. My voice sounds a little different in the two tracks, and I’d like to adjust the equalization of the second track to match the first.

I made a spectrum from old.m4a as follows:
Analyze → Plot Spectrum → Export (to old.txt)
Then I opened new.m4a, selected it, and did this:
Effect → Filter Curve EQ → Manage → Import (old.txt)

That generated this error: “old.txt: is not a valid presets file”

old.txt contained the following:

Frequency (Hz) Level (dB)
43.066406 -44.822819
86.132813 -30.400173
129.199219 -26.231615

21920.800781 -146.267380
21963.867188 -145.316299
22006.933594 -146.994080

The whole file was 512 lines, including the header. I know you recently changed from XML to TXT files, but I’m only using TXT.

I’d appreciate any suggestions on how to match the spectra of the two tracks. Thank you.

The problem is that “Plot Spectrum” does not export in a format that the Equalization effects support.

There is a plug-in somewhere that can convert from the “Plot Spectrum” format to the old (XML) Equalization format.
… It’s here:

Then there is a plug-in that is shipped with Audacity 2.4.2 called “eq-xml-to-txt-converter” that can convert the old XML format to the new TXT format. Use the Plug-in Manager to enable it.

Thanks for leading me through that whole process. I did get it to complete,
but in the end it didn’t make my voice in the new track sound the same as my
voice in the old track. The filter curve that was generated was at 0 dB from
20 to ~330 Hz, which was the first point shown. So I guess it didn’t do any
adjustment below 330 Hz, which includes the lower range of my voice. Above
330 Hz, the filter curve dropped, to -10 dB at 1 kHz to -24 dB at 3 kHz to
offscale (below -30 dB) above 4 kHz. The processed sound was really muddy,
with almost no high frequencies. I did better with the Graphic Equalizer
(trial and error) but still didn’t get a great match.

A side issue is that the spectrum from the older clip I like drops off a
cliff above 7 kHz (-54 dB there, -90 dB at 8 kHz). The newer clip I want to
adjust drops off more gradually and still shows somw power even at 20 kHz
(-88 dB). The clips from a few days ago are different in that way from any I
make now, even though I used the same mic in all cases. It seems that I
don’t have good control of some variable. I don’t think intensities that low
probably effect the timbre much anyway. Obviously I’m a real novice at sound
engineering. I teach auditory physiology and do know the basics of sound.

In any case, thanks again for your prompt help. I only started with Audacity
this month and have had a lot of success with it. The manuals are really
easy to search and use.

I’d guess that is because the older clip, at some point during it’s life, had a sample rate of 16 kHz. The sample rate limits the available frequency range to half the sample rate. Thus for a 16 kHz audio file, the maximum sample rate that can be represented is limited to “below 8 kHz”.
To represent the full audio range (up to 20 kHz), the sample rate needs to be over 40 kHz (the closest standard sample rate is 44.1 kHz).

I just recorded at a 16 kHz sampling rate, and the spectrum frequency axis
ended at 8 kHz. For the mystery recordings, up to 20 kHz was plotted, even
though there was ~no power above about 8 kHz. I had thought all the
recordings were done with 41.1 kHz. I’ll just have to move on with this, but
I’ll try to keep a closer eye on the settings and the spectra as I continue.
Thanks again.