I'm on a Cream kick at the moment, and decided it was time to hear Wheels of Fire as nature intended, and remove the CSG processing. I've seen some instructions for this on the forums before, but I didn't find a non-commercial/Audacity-based solution, so I did a trawl of the wider web to come up with the following, which I thought I'd share. Lots of credit to @lukpac for his good posts on this previously. First up - if you don't know what Haeco-CSG is, read this. tl;dr version - it's a old method for creating stereo mixes that would fold nicely to mono without overloading the centre channel, by rotating the phase of one channel. The downside is that the centre channel sounds muffled, and the stereo soundstage ranges from confusing to painful when listening on headphones. The worst part is that it was often baked in the master tapes, rather than only being applied when producing cutting masters, so it's still present on modern CD masterings. It affects a handful of albums, including the aforementioned Wheels of Fire. The good news is that it's fairly easy to get rid of using modern digital audio processing tools, even free ones! These instructions are for Windows; I'm not sure if it's possible to use VST plugins on Mac/Linux. Required ingredients: One CSG-processed album (I'm using the old anonymously mastered WG Polydor Fatboy of Wheels of Fire) Audacity, the freeware audio editor. The freeware BetaBugs PhaseBug VST plugin, available here. A pair of headphones Preparation: Install Audacity Install the BetaBugs plugin, then go to "C:\Program Files (x86)\VSTPlugIns" and copy PhaseBug.dll to C:\Program Files (x86)\Audacity\Plug-Ins (Re)start Audacity, go to Effect -> Add Remove Plugins and check that PhaseBug.dll is enabled. If not, enable it. Steps: Rip (or needledrop?) your album into WAV format. I recommend EAC! Identify which tracks have CSG applied - at least in the case of Wheels of Fire, it's not the entire album*. It's easy to confirm by OOPSing each track (if you've never OOPSed, see the post below which explains how to do it in Audacity). After OOPSing, the centre channel content (usually vocals) should be almost inaudible. If you can still hear them quite clearly, the track probably has CSG. * To save you some time, on WoF there's no CSG on the Live disc, but the studio disc has it on 6/9 tracks - everything apart from Sitting on Top of the World, As You Said and Pressed Rat & Warthog. If your version has Anyone For Tennis (e.g the DCC), I believe that also has CSG. Open a fresh copy of your file (with no OOPSing applied) in Audacity, then (with nothing selected) go to Effects -> Phase Bug and select PhaseBug.dll. After a pause, this should bring up the Phase Bug control: This lets you rotate the phase of each channel by dragging the red/yellow blobs - you can do this while the track plays. In this example, I'm rotating the right channel by -90 degrees to undo the CSG processing. In theory, CSG worked by rotating the right channel up to +120 degrees. However, apparently almost all recordings (including my example, Wheels of Fire) use the +90 degree "default" setting, which is what we're reversing here with our -90 degree rotation. If you're working with another recording, you may need to try different rotation values. There's always the possibility your mastering has the channels reversed, too. Make sure "Enable" is ticked, and hit the play button to play your track - you should hear an immediate improvement in the positioning and clarity of the centre channel, at least if you're using headphones. Once you think you've got the settings right, hit Apply to bake it into the track. You should see the waveform of the right channel change quite a bit. Save your new fixed file, then test it out by OOPSing it again - if you got it right, the centre channel should now be almost inaudible. Ditch your OOPSed version once your done - make sure you don't save it over your fixed version! Rinse, repeat until you've done all the affected tracks on the album. I'd recommend saving a "Right Channel -90" preset in PhaseBug (use the little burger menu) to speed this up. Burn yourself a new CD, and enjoy!