If you’ve ever watched an NBA basketball broadcast or seen a theatre play, you’ve likely heard (in some part of the audio mix) a floor microphone. These mics, when used correctly, add quite a bit to an audio mix without being overly noticeable (if noticeable at all) by the audience.
What is a floor microphone? A floor microphone is a boundary mic (PZM) that is positioned on the floor near an intended sound source. These mics are easily concealable and generally pick up sound in a hemispherical pattern. They are commonly used in sports broadcasts and in theatre productions.
In this article, we’ll talk about floor microphones in greater detail, discussing their applications and providing some floor microphone examples.
What Is A Floor Microphone?
A floor microphone, by definition, is any microphone that is positioned on the floor.
Generally speaking, floor microphones are boundary mics (also known as pressure zone microphones or PZMs).
What is a boundary microphone or PZM? A boundary mic is designed so that its capsule to be as flush as possible with a surface. Placing a boundary mic on a surface allows it to theoretically capture direct sound waves without any reflection from the surface. This yields a cohesive capture of sound.
For my recommended boundary/floor microphones, please check out my article Best Boundary Microphones.
Boundary microphones often have omnidirectional capsule, which effectively gives them a hemispherical polar pattern (picking up the sound in the available acoustic space). However, some boundary mics have more directional capsules which yields a more ellipsoid polar pattern.
Floor mics are often easily concealable and capable of picking up the entirety of the acoustic space around them.
Note that, although the term “floor mic” almost always refers to a boundary microphone positioned on the floor, it could also refer to any microphone that is positioned near or on the floor.
Floor Microphone Applications
Though floor mics can be used in many situations, the most common applications of floor mics are the following:
- Sports broadcasting (notably sports played on courts).
- Stage microphones in theatre near floor lights.
- Studio room microphones.
Floor Mic Application 1: Sports Broadcasting
Floor microphones can be used to great effect when positioned courtside in a sports broadcast. This makes them noticeably effective in basketball and tennis.
In basketball, the boundary mics set of the courtside floor are inconspicuous and act to pick up the shoe noise and ball dribbling on the floor.
In tennis, floor mics will help to add a bit more presence to the players’ footwork and to the ball as it bounces on the court.
Floor Mic Application 2: Stage Microphone
Floor microphones can be put to good use on stage, particularly in theatres.
Some actors have “small voices” that would benefit from amplification and sound reinforcement. Having a floor mic on stage (so long as the actor is near it when they speak) can provide this reinforcement.
In bigger theatre productions, the actors typically each wear a wireless lavalier microphone. However, in smaller budget productions (and even in the large ones) floor microphones can provide that extra bit of amplification.
As with any microphone in a live sound reinforcement situation, we must be cautious not to apply so much gain that the floor mic causes feedback!
If the boundary stage mic picks up too much stage rumble and footsteps, or does not provide enough gain-before-feedback, try hiding a small directional microphone in the same location and point it toward the actors’ speaking position.
Floor Mic Application 3: Studio Room Recording
Though boundary microphones are most often attached to the walls of a studio’s live room, placing them on the floor will yield similar results.
Floor microphones will help to pick up the sound of the studio room. A boundary mic on the floor will also typically pick up more low-end than if positioned on the wall due to the extra vibrations of the instruments on the floor (guitar amps, kick drums, etc.).
When using floor mics in a studio recording, it’s important that the musicians do not step too heavily (or at all) as their footsteps will certainly be picked up by the floor mics.
Floor Microphone Examples
Let’s take a look at some boundary mics that make for great floor mics:
- AKG C 547 BL
- Crown PZM 30D
- Audix ADX60
AKG C 547 BL
The AKG C 547 BL is a boundary layer condenser microphone with a hypercardioid capsule (rather than the typically omnidirectional capsule). The combination of AKG’s patented Phase Coherent Cardioid technology and the flush hypercardioid capsule of the C 547 BL provides the high directionality and natural sound of this top-of-the-line boundary mic.
The AKG C 547 BL work work very well as a stage floor mic since it is more sensitive in a single direction. This directionality (if positioned toward the actors and away from the loudspeakers) will greatly improve the gain-before-feedback of the mic and, therefore, the quality of the sound reinforcement.
Crown PZM 30D
The Crown PZM 30D is an industry standard boundary mic that works excellently as a floor mic.
Its sleek design makes it easily concealable and its omnidirectional capsule provides a beautiful hemispherical polar pattern. It frequency response is nearly flat and so the mic sounds very natural.
The Audix ADX60 is another hemispherical boundary microphone that works incredibly well as a floor mic.
This microphone is robust and easily hidden, making it a great candidate as a floor mic.
What is a PCC microphone? PCC is an AKG patent that stands from Phase Coherent Cardioid. Microphones with PCC technology are basically boundary mics with cardioid capsules. The capsule is designed to be flush to a surface so to avoid capturing any surface reflections. This yields a clean, phase-coherent signal (hence PCC).
What is an omnidirectional microphone? A microphone with an omnidirectional polar pattern is theoretically equally sensitive to sounds from every direction. The lack of directionality means that omni mics sound very natural; exhibit no proximity effect; and have poor gain-before-feedback.
For a detailed read on omnidirectional microphones, check out my article What Is An Omnidirectional Microphone? (Polar Pattern + Mic Examples).