UNLABELED VS ACCIDENTAL
SURROUND AND QUADRAPHONICS

HOW TO TELL THE DIFFERENCE

When a recording produces surround effects with matrix decoders, then either the recording is recorded with a quadraphonic or surround matrix, or something else has produced the effect (Note that nothing can produce any effect with a discrete system). Is there really quadraphonic or surround information there, is the decoder reacting to some other recording technique, or is the effect there by accident?

There are five possibilities (plus the possibility that the reason is not known to the public). Of the five, the quadraphonic or surround effect is Intentional (I) in three cases, an Unintentional side effect of a technique (U) in one case, and an Accidental combination of equipment use, location, and/or aiming (A) in the remaining case:

THE REASONS

The recording is made in matrix surround sound, but the label is disguised for only those who know (I)

  1. The record company placed a symbol indicating a quadraphonic recording on the cover and/or the label.
  2. The record catalog number is encoded to tell the type of recording (e.g. M, S, or Q for mono, stereo, or quadraphonic).

    RCA used a similar catalog coding system (M, AM, DM, D) to tell whether its 78 RPM record albums were made in the manual sequence (M), the slide-automatic sequence (AM), the drop-automatic sequence (DM), or were unsequenced (D) for different kinds of record changers (See record sequences).

The recording is made in matrix surround sound, but is deliberately not labeled as surround (I)

  1. The record company decided not to label it to keep from losing ordinary stereo sales. Often record stores put recordings labeled as being in surround sound in a special "quadraphonic" bin, instead of with the other recordings by that artist. The record company does not want that to happen.
  2. The artist recorded in a surround or quadraphonic system other than the system the record company has contracts for. Since the encoding can't be removed from the recordings, the only solution is to not label the recording.
  3. The artist recorded in a surround or quadraphonic system his own record company used, but a company that makes and distributes the artist's recordings in other countries has contracts for a different surround or quadraphonic system. Since the encoding can't be removed from the recordings, the only solution is to not label them.

It is NOT a good idea to not label a CD-4 or UD-4 record because they cause trouble with radio stations.

The record company doesn't know the recording is made in surround sound (I)

  1. The artist recorded in a surround or quadraphonic system other than the one allowed by the record company. Since the encoding can't be removed from mixed down recordings, the artist did not tell the record company.
  2. The record company does not want quadraphonic recordings, but the recording engineer put surround or quadraphonic effects into a recording anyway. He didn't tell anyone, so the recording is not labeled.
  3. The recording engineer put surround or quadraphonic effects into a recording, but didn't tell anyone. Therefore, the recording is not labeled.
  4. The recording is taken directly from a movie's film soundtrack, so it is recorded in Dolby Surround, but the record company does not know this.

A process intended for some other purpose creates a surround or quadraphonic effect (U)

  1. Attempts to pan instruments outside the normal stereo pair (wide stereo) cause those instruments to appear in the back speakers of RM, SQ, and Dolby Surround.
  2. Attempts to pan reverb outside the normal stereo pair cause the reverb to appear in the back speakers of RM, SQ, and Dolby Surround.
  3. The trick to make an instrument appear in both stereo speakers without centering it between them causes it to appear between the back speakers of RM, SQ, and Dolby Surround.
  4. The use of the Blumlein or Stereo-180 miking system puts sounds approaching from the sides into the back of RM, SQ, or Dolby Surround decoding.
  5. The Haeco CSG (Compatible Stereo Generator - also known as the Holzer system, and as a process used by Jerry Moss of A&M Records) was a system to reduce the size of the center soloist in mono playback. It was used on records produced by the A&M, Warner Brothers, Atlantic, Atco, and Reprise labels from 1968 to around 1971, although some bands continued using it afterwards. It reproduces correctly through a BMX or UD-4 decoder, and throws the center soloist to the left back in SQ playback. "CSG Process" appears on some record jackets or labels.
  6. Devices intended to simulate a stereo effect from a mono recording can create surround effects.

The recording techniques used accidentally produce a surround effect (A)

  1. Mic placement is such that one mic picks up another instrument with a time delay.
  2. A binaural pair of mics picks up some instruments with phase relationships that locate sounds in the back of the surround sound space.
  3. Reflections from the sides and back of a concert hall strike the microphones with random phase relationships.
  4. Sound approaching the back side of a supercardioid or hypercardioid mic is picked up out of phase, compared to other sounds picked up by the mic.
  5. Sounds approaching a Blumlein M-S microphone array from the side are sent to the back of an RM or SQ system.
  6. If the effect is caused by a time delay between mics picking up the same source, the perceived direction of the instrument will vary with which note is played.
  7. The sawtooth, sine, and square wave outputs of a synthesizer have phase differences between them. This can create surround effects when a different output is sent to a different mixer channel.

EXAMPLES

A Recording Company Deliberately Disguised any Quadraphonic Labeling (I):

A Recording Company Deliberately does not Label Recordings (I):

A Recording Company does not Know the Recording is Surround (I):

Recording Techniques Intended for Other Purposes Creates a Surround Effect (U):

Recording Techniques Accidentally Create a Surround Effect (A):

Recordings with Unknown Reasons for Surround Effects


HOW TO TELL BY LISTENING

What to look and listen for when determining whether the quadraphonic or surround effect is Intentional (I), an Unintentional side effect of a technique (U), or an Accidental combination of equipment location and aiming (A):

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