Removing Haeco-CSG processing using free tools

Discussion in 'Audio Hardware' started by Alexlotl, Mar 15, 2019.

  1. Alexlotl

    Alexlotl Forum Resident Thread Starter

    Location:
    York, UK
    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:
    1. Rip (or needledrop?) your album into WAV format. I recommend EAC!

    2. 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.

    3. 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:

      [​IMG]

      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.

    4. 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.

    5. 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!

    6. 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.

    7. Burn yourself a new CD, and enjoy!
     
    Strat-Mangler, Mbe, DavidD and 3 others like this.
  2. Alexlotl

    Alexlotl Forum Resident Thread Starter

    Location:
    York, UK
    OOPSing Tracks in Audacity

    OOPSing (OOPS = Out Of Phase Stereo) is a trick where you invert one channel so its centre-channel components cancel out the centre channel signal from the other channel, which leaves the centre channel almost completely empty. It's pretty easy to do in Audacity.

    I'd recommend trying this on a file that definitely ISN'T CSG first, so you can hear the desired effect and be sure you're doing it properly

    1. Open your WAV file.
    2. Click on the track name to the left of the track visualisation and select "Split stereo track to mono". Make sure you pick mono!

      [​IMG]

      This should give you two separate mono tracks:

      [​IMG]

    3. Select the entirety of only one of the two tracks - I find the easiest way to do this is to click into that track, then use Shift+J and Shift+K to extend your selection to start and end.

    4. From the menu, choose Effect -> Invert. This will invert the polarity of your selected track.

    5. Now hit play (it should play both tracks at once) - you should find the centre channel is almost completely muted, which usually has the effect of killing the vocals.
     
    Strat-Mangler, Mbe, DavidD and 3 others like this.
  3. Lord Hawthorne

    Lord Hawthorne Currently Untitled

    Location:
    Portland, Oregon
    Thank you, the world needs this.
     
    vwestlife likes this.
  4. Former Lee Warmer

    Former Lee Warmer Emotional Rescue

    Location:
    NoBoCoMO
    I wouldn't be mad if someone shared the results with me via DM...
     
  5. goodiesguy

    goodiesguy Forum Resident

    Location:
    New Zealand
    Did this ages ago in Adobe Audition to some tracks by The Association. Finally they sounded normal with the vocals dead center, not the weird OOP sound caused by Haeco-CSG.
     
  6. vwestlife

    vwestlife Forum Resident

    Location:
    New Jersey, USA
    On the "Classics Volume 18" compilation CD of Sergio Mendes & Brasil '66-'86, I discovered that "Fool on the Hill" and "Scarborough Fair" are Haeco-CSG encoded. And as of 2018, the latest official online release of "Fool on the Hill" still has not yet been remastered to remove the Haeco-CSG encoding, so I did it myself using Adobe Audition's Graphic Phase Shifter to apply a +90 degree phase shift to the right channel:

     
    rxcory likes this.
  7. marcb

    marcb Senior Member

    Location:
    DC area
    Thank you. I’ve been wanting to do this to my needledrop of the original Neil Young s/t mix for some time now. I’ll need to try it this weekend.
     
  8. Dillydipper

    Dillydipper Sultan Of Snark

    Location:
    Central PA
    Revelatory! As if I'd just tasted my first Snickers bar without rotten peanuts in it! :eek:
     
    vwestlife likes this.
  9. Andreas

    Andreas Senior Member

    Location:
    Frankfurt, Germany
    Thank you, that works like a charm for the Wheels Of Fire tracks (using the DCC Gold CD as the source).

    Could we make a list of albums and tracks where CSG was applied and which setting is needed to remove it? Does anybody know if Burt Bacharach - Butch Cassidy And The Sundance Kid (A&M 393 159-2 CD) has it and if the same "right channel -90 degrees" setting removes it? On first listen, it didn't sound right.
     
    Alexlotl and Natvecal. like this.
  10. Natvecal.

    Natvecal. JUST A LOW- FI GUY WHO LOVES A GREAT MASTERING

    Location:
    Oceanside,CA.
    yes to this on here.A list & how to correct :agree:
     
  11. Veech

    Veech Space In Sounds

    Location:
    Los Angeles, CA
    This is excellent info. I highly recommend investing the time as the results are remarkable especially on the DCC version.
     
  12. vwestlife

    vwestlife Forum Resident

    Location:
    New Jersey, USA
    I just remastered The Association's "Greatest Hits!" CD (original release) and it was a mess. Some tracks had no Haeco-CSG encoding, some had it with a +90° phase shift, and some had it with a -90° phase shift. I don't know if the CD was patched together from different copies of the master tapes, or if when they first did the Haeco-CSG encoding back in 1968 they just used whatever setting they thought sounded the best (or should I say, the least bad) for each track. Maybe a combination of both.
     
  13. Alexlotl

    Alexlotl Forum Resident Thread Starter

    Location:
    York, UK
    How does it sound now?

    Was it consistent for all tracks from a given album? The CSG was usually baked into the master tapes for an album/single, so I'd imagine a Greatest Hits compilation might have a mixture of +90 CSG/-90 CSG and no CSG sources. Also, based on WOF I'm guessing they didn't apply it at all for tracks where the centre channel naturally wasn't overloaded by playing in mono.

    Glad to see people getting some value from this thread. Still enjoying my fixed WoF!
     
  14. Natvecal.

    Natvecal. JUST A LOW- FI GUY WHO LOVES A GREAT MASTERING

    Location:
    Oceanside,CA.
    Could you list the tracks and the appropriate corrections done or not needed?
     
  15. vwestlife

    vwestlife Forum Resident

    Location:
    New Jersey, USA
    On the songs with center channel vocals and instruments it really improved their clarity and definition, especially when listening to headphones. It gets rid of that gauzy "half-out-of-phase" sound. (In fact, I once threw away a Petula Clark LP because I thought it had been mispressed out-of-phase. Only later did I discover that it was just a particularly bad-sounding example of Haeco-CSG encoding.)

    But on the tracks where everything is panned hard left and hard right and there really is no "center channel" to speak of, the difference is pretty much inaudible.
     
  16. McLover

    McLover Forum Resident

    Location:
    East TN
    The mixdown masters of these tracks likely were Haeco/CSG encoded. So, either DAW workarounds, or the label remixing these without the Haeco/CSG processing the only options. Your method is very effective.

    Off-Topic but related aside. However Haeco/CSG was not a total solution to the need for mono options for 45 RPM singles, or for LP, because these records still needed to be played on Stereo friendly equipment. Quite a good number of AM and FM mono Radio Stations often were still using older equipment which was not ready to play Stereo records safely (some of which was over 20 years old then). I have engineered at several such facilities (which had to do new tonearms, turntables, and cartridges to handle even high energy, loudly cut mono R&B, Rock, and Pop discs without mistracking, or rapid record wear from too heavy tracking forces, where 6 grams was the lightest said arm would track at).

    One station I part time engineered at was built in 1960, it's builder and owner installed Shure M3D cartridges with N7/21D styli wired for mono on the tonearms. Tracked around 2.5 grams. He did this so he could play Stereo and mono discs equally well. He was ahead of his time. He later upgraded to M 44-7 cartridges when he upgraded turntables and tonearms, when he built his FM, and simulcast part of the time. He was also an audiophile for many years at home.
     
    Curiosity and stereoptic like this.
  17. Andreas

    Andreas Senior Member

    Location:
    Frankfurt, Germany
    I have applied a phase adjustment of -90 degrees to the left channel for Raindrops Keep Falling On My Head and South American Getaway on the Butch Cassidy And The Sundance Kid CD, and it sound much more natural then before. Can anyone do a quality review for me? :)

    PS: A phase adjustment of -90 degrees to the left channel sounds the same to as a phase adjustment of +90 degrees to the right channel.
     
  18. Chauncey

    Chauncey Forum Resident

    Location:
    Cleveland, OH
    Do you recommend any other changes after successfully applying the PhaseBug effect to my DCC of WoF? Should I reduce the levels (White Room is at -1.4db after the phase adjustment). Any EQ? Thank you in advance for your advice. I have no idea what I'm doing!
     

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