A microphone for every application

Ligra DS | How to choose the right microphone according to use

Microphones, together with loudspeakers, are the most widely used professional audio products: think of meeting rooms, boardrooms and conference halls as far as installations are concerned, but also of travelling events (concerts), in studios, in live broadcasting (audio for cinema and television). In fact, the fields of application are vast, and for each of them it is often necessary to use several microphones, of the same or different types, to cope with every possible sound capture requirement.

The microphone in itself is a transducer, i.e. an instrument capable of converting one form of energy (acoustic) into another (electrical signal), but even without being technicians, experience teaches us how these instruments can be very different in construction, even though they perform the same function. Studio condensers rather than conference goosenecks, Lavaliers, headbands, shotguns, handhelds, you name it: each field of application requires a specific microphone, with precise technical characteristics, that is best suited to that particular shooting context.

The latter, from a technical point of view, is like a probe: it must be small enough not to disturb the sound field in which it is placed and at the same time have as linear a frequency response as possible. In this regard, it is good to dispel a myth: it is not true that microphones with a small diaphragm cannot capture bass or withstand high sound pressures: the opposite is often the case!

In this article, we will provide some rough indications to guide the best choice through the many fields of use of microphones.

Smart working and remote working

In smart working, it is essential to have a workstation equipped to interact remotely with colleagues or to hold remote meetings, where audio becomes crucial. Being able to rely on good speech intelligibility means facilitating work, at all levels.

When the audio quality afforded by the cheap microphone capsule inside a PC or webcam is no longer sufficient, we can look at decidedly more professional solutions such as the Clockaudio kit called The Presenter, consisting of a compact supercardioid microphone (i.e. with a very narrow polar pattern) that not only provides the best audio quality for these applications, but also only minimally enters the field framed by the webcam thanks to the goosneck arm on which it is mounted (CA 30-RF).
It is also ideal for use with a mechanical keyboard, as it is possible to direct the pickup pattern away from the noise generated by keypresses.

The capacitive touch switch TS 005 is specially designed for use with Clockaudio walk-through desktop microphones. With no moving parts, low-profile mounting and encapsulated electronics, the TS 005 offers multiple colours for clear and precise visual operation.

Using the same microphone, you can alternatively opt for the table base S 750 and avoid goosneck. Note that a phantom power adapter is required.


Huddle and meeting room

In meeting rooms, the latest trend, although not the cheapest, is to use controlled directivity microphones, i.e. those based on the beamformingbeam-forming'. Based on an array of microphone capsules, this technology makes it possible to discriminate the direction from which sound comes: this is done by amplifying those coming from a certain direction and attenuating the others.
To achieve this, the signals picked up by the individual microphones are summed using sophisticated digital signal processing techniques such as delay insertion, amplification and filtering. The 'beam' is understood here as a polar diagram, which is said to be omnidirectional when it is spherical. However, microphones characterised by this polar pattern are likewise sensitive to unwanted ambient noise that interferes with the useful sound, i.e. the speech of our interlocutor, worsening its intelligibility and often returning a dark, intubated sound.

An example of a controlled directivity microphone for ceiling installation is the Clockaudio TIM-1000designed for use in AV conference rooms and during meetings; it offers a performance that is difficult to match thanks to the automatic tracking of participants within the room, who can then move around without feeling tied to a certain position.

Based on APT technology (Adaptive Proximity Tracking(i.e. adaptive proximity tracking), a noise suppression system and a built-in equaliser, the TIM-1000 captures sound in the most effective manner. A key aspect of this microphone is that it supports Dante and AES 67 for audio over IP (AoIP); when multiple TIM-1000s are installed as individual units, the Dante audio stream from each unit is separate.

Clockaudio TIM-1000-CM, in-ceiling version

A less sophisticated alternative is to use one or more hanging microphones such as the Clockaudio C303W-RF.
It is a suspended, three-element electret condenser microphone designed for all-round pick-up in places such as meeting and conference rooms, courtrooms and other venues. It provides excellent speech intelligibility and also exists in a motorised retractable version. The RJ45 socket on the CCRM 4000 allows quick and easy connection of audio to the mixer or DSP. A 9-48 volt phantom power supply is required. The C303-D and C303W-D versions are those with a Dante interface.

Those on a tighter budget can opt for desktop microphones such as FONE540which also includes a speaker (i.e. a speakerphone) manufactured by AVer, which is USB and daisy-chained to enhance the audio-conferencing experience in personal workspaces, meeting rooms and medium to large conference rooms.

AVer FONE540: includes two omni-directional microphones for 360° pickup

An alternative solution involves the use of table-top, flush-mounted or top-mounted microphones of the boundary, i.e. pressure-zone type, with a hemispherical or enlarged cardioid polar pattern.

If the environment permits, a retractable microphone such as the Clockaudio CRM200SN-RF can capture up to six people arranged on a table, while if there are more participants, e.g. 18, 2 x CS3S-RF and 3 x CS2S-RFalways of the same brand.

At conferences, the speaker often needs to be able to move freely without being tied to a fixed position or have both hands free. In this case, the use of headbands, in jargon called headworns, or lavalier microphones, which can be clipped on to a jacket or shirt, is widespread.
The headbands are small and lightweight, equipped with a microphone capsule that is in most cases omni-directional (although many manufacturers have cardioid models). In the vast majority of cases, they connect to a radio bodypack, which the speaker clips onto his or her belt.

Clockaudio CMH2000, with omni condenser capsule
Clockaudio CW 7001T, bodypack

Conference and boardrooms

When we speak of conference and boardrooms, we are referring to rooms, large in size, equipped with a range of audio and video equipment necessary for holding the event, meeting or presentation: microphones, audio diffusion systems, video projectors, screens, translation systems, etc. Rooms of this type are usually equipped with a large table with well-defined multimedia stations for each participant and, in times of pandemics, physically separated from the adjacent ones. The table microphone is typically a gooseneck, optimised for speech pick-up.
Flexible and robust, it must be able to be positioned close to the participant's mouth to avoid raising the sensitivity of the mixer channel too much and to avoid possible feedback problems with the loudspeaker system. These microphones have a cardioid polar pattern, so in the open field they do not receive a signal from the back (180°).

Gooseneck microphones can be installed on microphone bases that also act as stands and add additional functionality (such as on/off), or they can be recessed directly into the table for an even more attractive installation design.

Examples are the Clockaudio series Haloavailable in rigid or semi-rigid versions, with a flexible part swivelling towards the speaker's mouth and equipped with a programmable circular LED near the capsule to indicate, for example, status.

Places of worship

In places of worship, one generally places (at least) a microphone above the altar, a gooseneck microphone on one or more lecterns, and a series of microphones for the choir, which must meet different requirements.

Whenever possible, the boundary microphone solution can be used for the altar, possibly a half-cardioid type:

Clockaudio C 008E-RF , available black or grey

This solution is actually not so common, as people normally prefer to use goosenecks that can, due to their geometry, get closer to the celebrant's mouth, especially if he speaks at low volume, and therefore require less gain on the mixer channel. Or hypercardioid microphones:

Clockaudio C 34EW/SR-RF, goosneck 48 cm
Clockaudio C 801EW-RF, hypercardioid, 26 cm

It should be noted that these microphones are available in white, as well as black, which is very popular and appreciated in church circles. There is a very interesting alternative that can be adopted when the architecture of the building allows it: the use of microphones to be hung from the ceiling by their own cable. such as the Clockaudio C 3S-RF-CP with cardioid capsule:

With these hanging microphones, the use of unsightly poles at the sides of the altar or in other positions where the speaker's presence is required is avoided. The C 3S-RF-CP is also available in a motorised roll-up version (CCRM 4000-RF).