{"id":203,"date":"2023-07-09T16:27:18","date_gmt":"2023-07-09T16:27:18","guid":{"rendered":"http:\/\/alessandrofois.com\/la-ripresa-stereo-della-voce\/"},"modified":"2025-06-29T22:58:35","modified_gmt":"2025-06-29T22:58:35","slug":"the-stereo-recording-of-the-voice-2","status":"publish","type":"post","link":"https:\/\/alessandrofois.com\/en\/la-ripresa-stereo-della-voce\/","title":{"rendered":"Stereo recording of the voice"},"content":{"rendered":"
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Stereo recording of the voice<\/h2>\n

You will rarely feel the need to record a lead vocal in stereo.<\/p>\n

In fact, when necessary, a \u201cstereophonization\u201d of the monophonic vocal source is often generated by means of processors such as delays, modulators, the harmonizer, or even by recording the vocal performance on 3 parallel tracks positioned on the left, center (the main one) and right.<\/p>\n

However, when recording very sparse arrangements we may feel the need to make an ambient recording, which may be inadvisable in very small recording rooms and\/or with imperfect acoustic treatment due to the greater incidence of poor quality ambient sound that would penetrate the recording audio program.<\/p>\n

For stereo recording of the voice we can distinguish between:<\/b><\/p>\n

1 \u2013 Stereo recording of the voice with L\/R technique<\/b><\/h2>\n

It involves recording the voice by positioning two microphones in stereo, choosing between the following techniques:<\/p>\n

Variable XY technique<\/b><\/h3>\n

\"\"<\/b><\/h3>\n

It involves placing two identical microphones one on top of the other in front of the singer's mouth, so as to obtain a perfect coincidence of the capsules, which must touch each other (without touching) in correspondence with the source axis coming from the singer's mouth.<\/p>\n

The microphones must be oriented, one to the right and the other to the left, so as to form an identical but opposite angle with the aforementioned axis, having a standard measurement of approximately 45\u00b0 for each microphone (which means that the angle between them will be 90\u00b0); alternatively, this angle may be reduced from 90\u00b0 to a minimum of 60\u00b0 or expanded to a maximum of 120\u00b0.<\/p>\n

Narrowing the angle will result in a narrowing of the stereo field and a decrease in the incidence of environmental reflections, while widening the angle will achieve exactly the opposite; the environmental incidence will be lower in acoustically large rooms and\u00a0 <\/span>well treated \u2013 the coherence of the stereo phase is almost absolute.<\/p>\n

ORTF Technique<\/b><\/h3>\n

\"\"It is obtained with two identical microphones with the capsules approximately 17 cm apart and oriented so as to form an angle of 110\u00b0.<\/p>\n

The axis between the two capsules, obviously, must be perfectly aligned with the axis protruding from the singer's mouth.<\/p>\n

This recording will produce a very natural but very ambient sound, so its use is generally limited to sufficiently large recording rooms with properly treated acoustics; the coherence of the stereo phase is good.<\/p>\n

Spacing technique<\/b><\/h3>\n

It is obtained with two identical microphones positioned, one to the right and the other to the left of the singer, so that, with a 45\u00b0 inclination, they direct the capsules towards the singer's mouth, at a distance of approximately 20 cm from it.<\/p>\n

This recording technique produces a wider stereo dimension, maintaining acceptable stereo phase coherence and a more moderate ambience compared to the ORTF technique.<\/p>\n

It is also possible to place a sound-absorbing screen between the capsules of two microphones, perpendicular to the axis of voice emission.<\/p>\n

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The advantage of these various techniques is that they produce a very natural and pleasant sound, which can be appreciated in acoustically well-set up recording rooms.<\/i><\/b><\/p>\n

The disadvantage is that they don't produce a decidedly dry sound, which is often a necessary requirement for many applications, especially in the pop field.<\/i><\/b><\/p>\n

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Mono recording of the source + stereo ambient field<\/b><\/h3>\n

This mode, which uses 3 recording channels instead of two as in the previous examples, is most commonly used as it is considered more useful and versatile in most applications.<\/p>\n

It involves recording the voice in mono as usual, and simultaneously making a take\u00a0 <\/span>stereo of the ambient field which can then be adjusted as desired during the mix.<\/p>\n

The positioning of the 2 microphones to be used for the ambient field can be left to the creativity of the sound engineer, thus obtaining personalized effects. vocal ambient field<\/b>.<\/p>\n

However, there are two main suggestions, which can be used alternatively as desired:<\/b><\/p>\n

    \n
  1. Place two identical studio microphones in the Blumlein position, both with a figure-8 polar pattern, overlapping them on the vertical axis as in the XY technique above (see figure at right); the angle between the two microphones on the horizontal axis must be exactly 90\u00b0; position these microphones behind the singer at the back of the room, approximately one-third of the way down;<\/li>\n
  2. Place two identical studio microphones in a cardioid position behind the singer at the back of the room, approximately 1\/3 of the way down, so that they are 1\/3 and 2\/3 of the way down the room, pointing them towards the ceiling.<\/li>\n<\/ol>\n

    When mixing, this stereo pair of microphones could be useful to give a touch of naturalness to the vocals in the mix, a very interesting solution especially for small acoustic groups, provided that the recording room \u201csounds good\u201d.<\/p>\n

    2 \u2013 Stereo recording of the voice using M\/S technique<\/b><\/h2>\n

    \"\"For this mode you need 2 microphones, not necessarily identical, of which:<\/b><\/p>\n

      \n
    1. n.1 cardioid positioned frontally towards the voice, which will be dedicated to the recording\u00a0 <\/span>main (as if it were a normal standard mono recording)<\/li>\n
    2. n.1 with a figure 8 polar pattern, oriented perpendicularly to the first microphone (with a 90\u00b0 angle), so as to record the right and left sides of the room (see figure)<\/span><\/li>\n<\/ol>\n

      Microphone no. 2 will not pick up the direct voice but only the reflected one thanks to the double counterphase recording which (virtually) cancels the sound coming from a 90\u00b0 angle on both sides.<\/p>\n

      This microphone, on the other hand, will perfectly capture the reflections induced by the voice on the environment.<\/p>\n

      At the end of the registration we will have:<\/b><\/p>\n

        \n
      1. an M (middle) channel with the direct sound of the source, in mono, recorded by microphone no. 1<\/li>\n
      2. an S (side) channel with the reflected sound of the source, in mono, taken by microphone no. 2<\/li>\n<\/ol>\n

        At this point, we'll need to duplicate the S track and phase-invert it (only the duplicated one), assigning the original entirely to the left channel via the panpot, and the duplicated one entirely to the right channel. The M track, on the other hand, should remain centered.<\/p>\n

        At this point we will have built a sort of stereophony<\/b> which will also allow us to independently adjust the direct sound and the reflected sound converted to stereo.<\/p>\n

        Phase coherence is total since, in case of listening in mono, the L and R channels, being identical but inverted in phase, would cancel each other out, leaving only the M track containing the direct sound.<\/p>\n

        Creative variation of the MS technique<\/b><\/h2>\n

        Instead of the single microphone no. 2 with a figure of 8, no. 2 identical microphones with a cardioid polar pattern should be used, with the capsules overlapping until they almost touch each other, pointed in opposite directions, perpendicular to microphone no. 1 (always 90\u00b0).<\/p>\n

        A highly effective sound-absorbing acoustic screen must be placed between the singer and these microphones, capable of preventing the direct sound from being picked up by the two lateral microphones.<\/p>\n

        The central microphone capsule no. 1 should appear above the screen, pointing towards the singer's mouth.<\/p>\n

        At this point, the 3 tracks will be "pan-fried" as before:<\/b><\/p>\n

          \n
        • the central microphone (M) in the center<\/li>\n
        • the other 2 microphones, one completely to the right and the other completely to the left<\/li>\n<\/ul>\n

          Now you will have obtained something similar to before, that is, a direct central channel and 2 side channels containing essentially the reflected sound, mixable independently.<\/p>\n

          However, there are some differences that will correspond to some advantages and just as many disadvantages:<\/b><\/p>\n

            \n
          • the side channels will also contain a small part of the direct sound, in addition to the reflected sound, with the risk of shifting part of the direct sound if the S channel is kept at a very high volume<\/li>\n
          • The stereo sensation offered by the S channel is more natural than the pure M\/S system<\/li>\n
          • you can decide to use the S microphones by leaving them in phase or by inverting the polarity of one of them: you will obtain slightly different results between which you can choose (generally it will be better to leave them in phase)<\/li>\n
          • the phase correlation will be decreased but the center channel will not suffer substantially, which will allow you to still perceive some ambient reflected sound even when listening in mono<\/li>\n<\/ul>\n
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            For more information on Audio Recording, Editing and Digital Tuning<\/h2>\n
            \n

            Audio Recording, Editing and Digital Tuning Manual<\/a><\/p><\/blockquote>\n