I'd start with a high-pass filter. It looks like about a 7Hz* "wave", so a 20Hz high-pass filter should knock it down without affecting the sound. It's a rather large signal, so you need to use a steep filter, and you may need to use a higher cutoff frequency, or run the low-pass process more than once, to "kill it".
If there are higher-frequency audible side-effects of the warp, filtering-out the low frequency won't clear-up those noises, and there may be no way to clean-up the recording. If all else fails, buy the CD!
You can try noise reduction, but noise reduction usually works best on low-level
background noise... This is high-level foreground noise, and I suspect that noise reduction will adversely affect the sound.
* In case you don't know, frequency (Hz) is the inverse of the period (the time for one complete wave). I see approximately 2-cycles over about 0.3 seconds... 1/0.15 = 6.67Hz. (You may want to zoom-in and make a more-accurate measurement.)
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My "standard comments" about recording LPs.
DougDbug wrote:There are lots of hints & tips about recording/digitizing LPs on
this page.
I will almost always do the following:
I always
check for clipping. I run
Maximize to check the peak level, and if it's 0dB I assume it's clipped and I re-record. (Clipping is distorted flat-topped "waves", caused by trying to go above the digital maximum of 0dB.)
I use
Wave Repair ($30 USD) to
remove "ticks", "clicks", and "pops". It does an amazing job by replacing the defect with the just-preceding or just-following few milliseconds of sound (or a couple of other methods). WARNING - This can be very time consuming. Wave Repair seems to work best when used manually. It usually takes a day (or a weekend) for me to fix-up a recording.
I
try some
noise reduction and/or
noisegate. Sometimes there can be artifacts (side effects), so I don't always apply these "filters".
If it's an old "dull sounding" recording, I'll add some high-end boost (with the
Equalizer).
After I'm done with any other processing, I always
Maximize (normalize) or use GoldWave's
MaxMatch. This sets the level so that the peaks are exactly 0dB, giving the best signal-to-noise ratio at playback time. It's generally best to normalize the whole album as a single WAV file to retain the
relative level between the tracks... Some songs are
supposed to be louder or softer than others.
Whenever I burn a CD, I always
make an extra archive/back-up copy. If I'm doing lots of processing, I make an un-processed archive CD too.
The remastered version, done by the Ig himself, is clip city...the waveforms of the remastered tracks, especially compared to those of the originals, are featureless rectangles, no peaks or valleys whatsoever. Squashed by overcompression, gain jacked through the roof, so much detail lost...it really is the difference between sounding "raw" & sounding "like crap".