Bleeding music

August 16, 2014
 by Paul McGowan

In my post of a few days ago, Steve Hoffman, he mentions on his cheap Henry Mancini CD there’s really good ‘bleed’ that he likes to listen to as a means of evaluating equipment’s ability to resolve small details. Several of you caught that reference and asked me to explain what he meant.

‘Bleed’ refers to ‘tape bleed’ a ghosting you can hear on some cuts of music. A good example is one I’ve used often, the Shelby Lynne title track Just a little lovin’. In the middle of the song, the band stops playing, there’s a pause and Shelby sings alone just for a moment. If you listen closely when she sings:

‘…This old world, wouldn’t be half as bad, It wouldn’t be half as sad, If each and everybody in it had, yeah’

Half a second before the first line quoted in the lyrics, you can hear a ghost of her singing ‘This old world’ just before she actually sings it – if your system is resolving of small details.

Tape bleed happens when the tape has been around for a while and the layers of tape sit close to each other on the reel. Because tape is a magnetic medium, each layer slightly magnetizes the layers above and below when tightly wound on the reel. If they sit long enough on the reel, this bleed happens to every turn of tape. You only hear the bleed when the musicians stop playing for a brief moment.

That’s tape bleed.

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23 comments on “Bleeding music”

  1. Fine description of tape bleed/print through, but I think Mr. Hoffman is actually talking about Microphone bleed, especially with his references to hearing the room. When they used to record everybody all at once in a big studio, and the engineer was less than careful (or purposefully less than careful) about where he placed the microphones, you got “bleed”: the guitar mic picking up some of the drums, say, or the mic placed in front of the background singers getting some of whatever was bouncing off the walls. This can result in a happy accident (or again with intent in the hands of the best engineers). You get the room, you get an aural picture of the recording space. Think classic Blue Note, or Brubeck/Miles via Columbia in the 1950s…great music, but also great recordings with a sense of where the players actually were as they played. Holy holographic!

  2. Right. More commonly known as “print through”, “bleed” usually refers to instruments feeding into each other’s microphones during recording. There is another phenomenon related to print through that occurs on LP records where the outer groove wall is effected by the adjacent modulations of the inner groove wall next door creating a ghost image that predicts the sounds to come. Usually happens when it’s quiet right before the song begins.

  3. I am with j Haynes. In this sorry Paul. But tape bleed is what you state. And in so we are showing both our age and having good systems. What they do in studios, to stop bleed of all kinds I do not know. I hear echo from studio,s often in recordings. Hell it’s sign of good equipment as only the good stuff gives us these little deatils we cherish so much. If the setup and recording g is good enough you can here the echo reflect a second time. Such a cd is Kansas City shout on Pablo rec , count Basie . Even with just voices if setup right you can here his voice echo as he sings .
    Al

  4. Yes, the “bleed” Steve refers to is the microphone’s pickup of adjacent sounds and the acoustic environments. One can hear this effect clearly in all classical recordings and mostly older jazz and pop recordings because of the relative distances of the mics to performers on such recordings. Modern pop and quite a few modern jazz recordings don’t have “bleed” for several reasons: 1) the mics are usually quite close to the performers or instruments, 2) the performers/instruments were isolated from each other at the studio, or 3) individual instruments may have been recorded piecemeal at separate times in overdubs; i.e.: no “live” performance together ever took place for the recording. #3 is how almost all modern pop production takes place and it’s been that way for decades now.

    As described previously, there is analog tape “print-through” where the magnetic signal from one layer of tape is transferred to the next layer. On vinyl, there also can be a pre- and post-echo effect which can sound much the same as analog tape print-through. The groove modulation of one revolution is transferred or impressed upon the next or previous revolution (or two) of the disk. This effect happens when 1) the groove pitch is too tight (the groove spacing is too close) when the lacquer master is cut, or 2) the record press pressure is set too high and the grooves are distorted during the pressing process. During the cutting of the lacquer master, the disk mastering engineer ordinarily will expand the disk cutting pitch for several revolutions at the beginning of each track to minimize pre-echo, especially if the opening notes are loud or percussive. The program material determines the pitch setting. Post-echo at the lacquer cutting stage is prevented again by setting the cutting pitch appropriately. If a loud sound precedes a quiet passage, the cutting pitch is kept coarse by at least one revolution to prevent the loud sound from being impressed upon the following quieter passage. The cutting pitch and groove depth is continuously adjusted throughout the disk side by the disk cutting computer which is fed by the preview signal of the analog tape deck or digital playback source. The preview signal is one revolution (set by the disk rotational speed) ahead of the recorded signal. The cutting engineer can make manual adjustments to the cutting pitch and depth as needed.

    Pre- and post-echo caused by record press pressure is prevented by press operation of an experienced operator who knows to look for such problems.

      1. My favorite example of print through is on the Traffic album John Barleycorn. It must have been on the outside of the reel because the piano solo precedes itself by several seconds.

  5. As I understood it, what you heard was called “pre-echo” and it was said to be the result of “print through” on the tape. I always wondered if this was the result of the tape magnetizing one layer from another or in part or instead due to the cutting stylus deforming the previous outer groove in addition to the one it was cutting. This possibility occurred to me because I never heard a corresponding post echo which should occur with print through of the tape. I didn’t need a very good sound system to hear it, it was audible with a Sonotone 8TA cartridge and later with an Empire 880P cartridge. I think one record you can hear it on is Harry Belafonte at Carnegie Hall. This is one kind of distortion you NEVER get with DDD CDs. The only way to know for sure would be to listen to the tape…or a CD made from the tape in a later re-issue to see if it is present there too. I never cared enough about it to investigate it myself. I agree with the others who say you misinterpreted what Steve Hoffman meant when he said ” Many of the songs have great bleed, you can hear the studio, the chorus, etc. in a real space.” While I may not have learned to focus my attention of correct/incorrect absolute phase if I can even hear it at all, one thing I can hear and can focus on is real space as expressed in sound….and these recordings and sound systems don’t have it. I think anyone with normal hearing can learn to hear it. Just ask Daniel Kish, the blind man who taught himself to see using sound if it isn’t true.

      1. I’m a show me kinda guy. I’m a little dubious about tape “print through.” To magnetize a magnetic tape requires a high frequency bias superimposed that’s from 40 kHz to 150 kHz and at least ten times more powerful than the recording signal. I’m not saying it isn’t possible that tape print through happens but I’d like some documentation of someone having studied the phenomenon just to let me know it’s more than one more unproven theory. http://en.wikipedia.org/wiki/Tape_bias

        1. Here’s a reference to tape print through. It can happen but to what degree does it occur when the vinyl recording is made not long after the tape has been recorded and using 15 or 30 ips high quality tape on a thick acetate or polyester ribbon? http://en.wikipedia.org/wiki/Print-through Notice that print though is also referred to as bleed through. Ya larns sompin’ new everee day.

    1. Not sure if anyone will read this after all these years, but…
      I just heard an example of ‘print-through’ that couldn’t possibly be related to adjacent-groove deformation when printing master disks with a stylus. Heard it on a 1967 recording streaming on Spotify. Unless digitized from a vinyl master (very unlikely), the pre-echo must be the result of tape-wrap print-through. The song is “Celebrated Walkin’ Blue” by Taj Mahal. Print-through pre-echo is evident throughout the first 1:15 of the track.

  6. I hear music as a conversation, and separating the musicians in space or time destroys the interaction. The biggest selling bands in history were the house bands at Motown and Stax Records, and the Wrecking Crew. At Motown everybody crowded into Berry Gordy’s basement, and Phil Ramone’s trademark sound was locating a mic or two in a place in the room where all the sound was bleed. Likewise the Stax crew, AKA “Booker T and the MGs” or the Blues Brothers band recorded together in a converted movie theater making hits for Otis Redding, Wilson Pickett, Sam & Dave, Isaac Hayes et al. The Wrecking Crew were an informal group of studio musicians who traveled around LA making most of the ’60s hits from that town. The “music factory” approach had the whole album captured in a day or two, like recording in the Big Band, Bebop, Cool Jazz and Rock & Roll eras that preceded it. The advent of commercial multi-track tape decks coincided appropriately with psychedelia, which was about fantasies. If you want to get real, you have to play the whole song from beginning to end together in the same room – with room “bleed”.

  7. The print through phenomenon is/was quite common in recording. In spite of the thick backing which was applied to improve contact between the pressure roller and the capstan, it was also there to reduce print through effect. To further reduce the effect, we would allow the reel to “wind off” as if playing to the end and leaving it on the take-up reel. The now new empty reel would become the next reel’s take-up reel and so on. The reason this was/is done, was so the print through would be reduced when the reel was rewound for playback, mixing of the multitrack or any time the 2-track master was used.

    Take this with a grain of salt if you wish, but this is what I was taught in the mid 70s when I started learning professional recording as a gofer/2nd engineer in the studio. Those guys were gods to me then and I took their words as gospel. Auditioning the reel after the rewind secured this technique in my repertoire for future use. I could hear a reduction and that was good enough reason to use it.

  8. This might be a first. The DirectStream is on the cover of both TAS and Stereophile in the same month. What’s next? The cover of The Rolling Stone? 🙂

  9. I’ve occasionally dabbled in multitrack recording of friends’ bands. In a real studio there are more options for instrument placement than at someone’s garage or practice space. I’ve used mic nulls to minimize, but for one group (who shall remain nameless) the guitarist/singer did not want to overdub. Problem was, the instruments were as loud in the vocal mic as he was. In mixing I had to leave the vocal mic up throughout each piece and tailor the instrument sound around the bleed. If I tried muting or lowering the mic track when he didn’t sing, it was painfully obvious. The results weren’t pretty. “Good tone” went out the window…

    1. I’d have used a supercardioid or shotgun mike, had the singer turn around 180 degrees so the mike was pointing away from the instruments, and maybe put the singer behind the instruments. Or you could just have dubbed the singing in separately using sound on sound. Watching people perform at recording sessions with headphones on, it seems to me a lot of recordings are made that way.

      1. I was using a hypercardioid. No chance to move anything around in a 12′ square room full of 3 bands’ equipment. Barely room for me and my small kit to squeeze into the area by the door; had to move my case to go in or out. They also played quite loudly. To be fair, this was band _practice_ I was recording. We all agreed that to do anything serious something would have to change. Then the band broke up…

  10. I was very easily able to hear the “bleed” (regardless of how it got on the recording) with my headphones on all three of my home stereo systems including my iPhone at reasonable listening levels. I was able to hear it on my main two channel setup but at volume levels far far above what I would ever listen to. I generally listen with my volume set to send about 60db at my listening position maximum, what kind of volume levels are you listening to in order to hear this easily in your system, or do you also have to turn it way up to hear the bleed?

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