MicPlot
Open MicPlot
Guides › Spot mics
Orchestral spot mics: where they go, how high, and when to leave them out
Spot mics are the microphones placed close to a section or an instrument to add definition the main array cannot give on its own. Used sparingly and placed with care they are invisible; used badly they turn a hall recording into a multitrack. These are starting positions that work in most halls.
What a spot is for
The main array (a Decca tree or a spaced pair, usually with outriggers) carries the balance and the hall. Spots do three narrower jobs:
- Definition. Woodwind solos, pizzicato, the attack of the timpani — detail that is soft or distant at the tree.
- Balance insurance. A section the conductor keeps under, or a quiet instrument (harp, celesta, guitar) that the hall swallows.
- Image. A little spot level pulls a section to its correct place in the stereo picture when the tree alone leaves it vague.
What a spot is not for is replacing the tree. If the mix is mostly spots with the tree underneath, it will sound like a studio record of an orchestra, and the hall you paid to hire will be missing.
Starting positions and heights
Measure from the front desk of the section, not from the stage edge; the plot converts it. Heights are capsule height above the stage floor. Treat the numbers as a first morning, not a rule.
| Section | Where | Height | Notes |
|---|---|---|---|
| Violins I and II | Over the second or third desk, inside the section's outer edge, pointing down toward the front desks | 2.4–3 m (8–10 ft) | Too close to the first desk and you get one player, not a section. One per section; a pair across the section for a wide group. |
| Violas | Over the second desk, from the audience side | 2.4–3 m (8–10 ft) | Violas are the section most often lost at the tree; this spot earns its keep. |
| Cellos | Over the second desk, slightly to the inside, aimed at the f-holes of the front players | 2.1–2.7 m (7–9 ft) | Lower than the violins: the sound comes from the body, which sits lower. |
| Basses | In front of the section, about 1 m from the front instruments, aimed at the f-holes | 1.2–1.8 m (4–6 ft) | A short stand or a mic on the principal is common. Keep it out of the walkway. |
| Woodwinds | A pair over the gap between the two wind rows, one each side of centre, pointing down | 2.7–3.4 m (9–11 ft) | From the front of the section so flutes and oboes are not blocked by stands. Add a solo spot (flute, oboe) only if the piece needs it. |
| Horns | Behind and above the section, where the bells point (the sound goes backwards) | 2.7–3.4 m (9–11 ft) | A spot in front of the horns hears mostly the reflection off the wall behind them; if that wall is good, use it. |
| Trumpets, trombones | In front of and above the section, well back from the bells | 3–3.7 m (10–12 ft) | Higher and further than feels natural: brass spots close in get bite and spit. Often one spot covers the row. |
| Timpani | Above and slightly in front of the drums, aimed at the heads | 2–2.7 m (6½–9 ft) | Watch the mallet height: a low spot gets hit. |
| Percussion | Over the mallet instruments; snare and bass drum from the front | 2–3 m (6½–10 ft) | Bass drum spot low and a little off-centre of the head; cymbals and triangle usually come through the tree fine. |
| Harp | About 1 m from the soundboard, on the player's right (the bass strings), pointing at the board | 1.2–1.8 m (4–6 ft) | Pedal noise lives low on the instrument; aim above the base. |
| Piano, celesta | Just inside the lid at the curve, or over the hammers for celesta | 1.2–1.5 m (4–5 ft) | For a concerto the piano gets its own pair, not a section spot. |
A typical symphony session carries eight to twelve spots on top of the tree and outriggers: two per string section at most, a wind pair, a brass spot or two, timpani, and a harp or keyboard where the score has one. If the mic plot shows twenty spots, something is being solved on the console that should have been solved with the tree.
Mixing them
- Delay them to the tree. A spot 1 m from its section is 8–12 m closer to the sound than the tree, so its signal arrives 25–35 ms earlier and pulls the section forward. Delay each spot by its distance difference to the tree (about 3 ms per metre, or 1 ms per foot) and the section stays where the tree put it.
- Keep them low. Bring a spot up until you notice the detail, then back it off a little. A good spot is one you only hear when you mute it.
- Pan to the picture. Pan each spot to where that section sits in the tree's image, not hard to a side.
- High-pass the close ones. Stand rumble, pedal noise and floor-borne thumps come up the spots long before the tree.
Putting them on the plot
Every spot needs the same four things on the mic plot: channel number, position measured from the stage edge and centre line, height, and the stand. The stand matters more for spots than for anything else — a 10 ft wind pair needs tall boom stands the hall may not own, and a bass spot on a short stand needs to be where no one walks. Write the stand type on the plot, not only on the input list, so the crew builds the right one at the right spot.
Questions engineers ask
How high should orchestral spot mics be?
Most section spots sit at 2.4–3 m (8–10 ft) above the stage floor, pointing down at the front desks. Brass spots go higher and further back (3–3.7 m); cello, bass, harp and keyboard spots lower (1.2–2.7 m), nearer the body of the instrument.
How far should a spot mic be from the section?
Over the second or third desk for strings, about a metre from basses and harps, and over the gap between the rows for woodwinds. Close enough for definition, far enough to hear a section rather than one player.
Do spot mics need to be delayed?
Usually, yes. A spot is much closer to its section than the main array, so its signal arrives earlier and pulls the section forward in the image. Delaying it by about 3 ms per metre (1 ms per foot) of distance difference to the tree keeps the section in place.
How many spot mics does a symphony orchestra need?
Eight to twelve on top of the tree and outriggers is typical: up to two per string section, a woodwind pair, a brass spot or two, timpani, and harp or keyboard when the score has one.
Place every spot with its height, in 3D
MicPlot puts real orchestral seating on the stage, so a spot lands over the right desks and prints with its distance from the edge, its height and its stand. Free, no signup.
Open MicPlotRelated guides
- Decca tree placement: a practical guide
Starting dimensions, height, outriggers, and what to move when the balance is off.
- Microphone heights for orchestral recording
Height is the adjustment that changes an orchestral pickup the most and gets written down the least. These are working heights for each…
- How to make an orchestral mic plot
What goes on the plot, the order to build it in, and the mistakes that get a rig redone.