Released 02 Aug 2022, Last Updated 03 Aug 2022
Si estás pensando en comprar un micrófono, sin duda te has encontrado con micrófonos de condensador junto a micrófonos dinámicos e incluso posiblemente micrófonos de cinta. Por supuesto, puedes usar cualquiera de ellos para grabar audio, pero ¿qué es exactamente un micrófono de condensador y cuándo deberías optar por usar uno en lugar de sus alternativas?
En este artículo, te explicaremos los conceptos básicos de cómo funciona un micrófono de condensador, los diferentes tipos que encontrarás comúnmente, la comparación entre micrófonos de condensador y dinámicos, y en qué aplicaciones de grabación son útiles.
El RØDE NT1-Un micrófono de condensador de gran diafragma destaca en la grabación de voces gracias a su impresionante calidez y claridad.
Simply put, condenser microphones are more sensitive than their dynamic siblings, and due to their design, are better at picking up more detail in a recording, with lower self-noise and better accuracy across a wider frequency spectrum.
With that said, this increased sensitivity comes with some disadvantages in certain recording scenarios. Condensers will generally pick up unwanted background sounds more readily, so aren’t as suited for use in spaces with lots of reflective surfaces or in particularly noisy environments. Also, condenser microphones are typically less rugged than dynamic microphones and may not be suited to applications like live performance, where they may be dropped or knocked around.
With these inherent characteristics, condenser microphones are best used in situations like studio recording (with some exceptions, which will be covered below) where you have a more controlled environment and require the best quality audio possible, but they may not be as appropriate in noisy rooms or loud stages.
Let’s take a closer look at what a condenser microphone is and when’s best to use one.
Like every microphone, condenser mics utilise a sensitive conductive material (known as a diaphragm) that vibrates when sound waves hit it, which in turn induces a current in another element and creates an electrical signal.
In the case of condenser microphones, their capsule contains an extremely thin membrane of conductive material as its diaphragm, which is next to a solid metal plate that is charged with a current. When sound waves hit the sensitive diaphragm, it vibrates back and forth, transferring this current to the metal plate via induction and thus creating an audio signal.
The resulting signal doesn’t have a strong enough current to be output as is, which is why condenser microphones have an on-board preamp to boost it. This preamp – and in some designs, the charged metal plate as well – requires external power to function. In most modern, transistor-based microphones, this is supplied by 48V phantom power sent via the XLR cable used to connect the mic to a mixer or audio interface. Without this external power, condenser microphones cannot operate, so make sure your recording device can supply it and it is switched on when using one.
La interfaz de audio RØDE AI-1 proporciona alimentación fantasma de 48V a través de su entrada XLR para su uso con micrófonos de condensador.
While we’ve covered the basic foundations of how a condenser microphone works, there are a few different approaches to the formula that further define mics in the category.
Large-diaphragm condenser mics such as the RØDE NT1-A utilise a larger membrane in their capsule, as you may have guessed. While there isn’t necessarily an industry standard for what capsule size qualifies for this category, a condenser microphone with a diaphragm of 1 inch (25.4mm) or greater is considered a large diaphragm as a rule of thumb.
One of the biggest technical advantages of this design is that its larger diaphragm can generate a higher signal voltage, which in turn results in the microphone producing less of its own noise (self-noise).
Large-diaphragm condensers typically have a less consistent pickup pattern than small-diaphragm counterparts. While this may not be ideal if you're aiming for a perfectly uncoloured recording, it is what accounts for the ‘lush’ and ‘warm’ character often attributed to these microphones and is what makes them ideal for recording vocals, and in a range of other applications.
Micrófonos de condensador profesionales como el RØDE NT1-A son ideales para grabar desde voces hasta guitarras, piano y baterías.
Small-diaphragm condenser mics like the RØDE NT5 typically produce a flatter and less ‘coloured’ signal than their large-diaphragm counterparts, meaning they give you a very accurate audio image. They typically have an extended low- and high-frequency response, and a consistent pickup pattern that helps capture sounds as ‘naturally’ (or ‘neutrally’) as possible. This may or may not be ideal for you, depending on the recording application – for example, small-diaphragm condensers aren’t typically used to record vocals, but like many recording scenarios, it comes down to a matter of taste.
Just like their large-diaphragm brethren, there is no hard-and-fast rule for what qualifies as ‘small’, but it’s generally accepted that it refers to anything with a diameter of half an inch (12.7mm) or less. This smaller membrane also results in a superior transient response ideal for recording sound sources with a fast attack, like piano, drums and stringed instruments.
While almost all large-diaphragm microphones are side-address (meaning, you aim the sound source perpendicular to the microphone body), small-diaphragm mics can be either side- or end-address.
Tube condenser mics like the RØDE NTK utilise a vacuum tube (also known as a valve) in their preamplifier circuit rather than transistors. This style of microphone was the first to be developed amongst the condensers, but when transistor (also known as ‘solid state’) technology became widely available it largely replaced tubes due to the latter’s ‘imperfections’. These imperfections have since become revered for the character they impart, and tube mics have seen a resurgence over the past few decades.
Among the qualities of a tube microphone is that they tend to add pleasant harmonics to a sound source, as well as subtle saturation and compression. While this character can be desirable, tube mics also tend to come with a higher self-noise level and require a separate power supply to operate – 48V phantom power from your audio interface won’t cut it.
Shotgun microphones are a type of condenser mic distinguished by their long, tubular design. The purpose of a shotgun microphone is generally to record audio from a distance while maintaining focus and clarity.
In terms of differences in design from other types of condensers, the capsule is housed towards the back of the body in a shotgun microphone, with what is known as an 'interference tube' in front of it. This tube has evenly spaced perforations along its length (usually in the form of slits or, in the case of RØDE mics like the NTG5 and VideoMic NTG, circular openings). Sound waves enter through the front of the microphone, as well as from the side ('off-axis') via these perforations. This disrupts (or 'interferes' with) how the sound waves reach the capsule, resulting in these ‘off-axis’ sounds being filtered out through a process known as phase cancellation.
What does this actually mean in practical terms? Shotgun mics are very 'directional' microphones, meaning the audio they produce is very focused on what it is pointed at with excellent rejection of unwanted sounds from the side and rear. This makes them ideal for filmmaking applications when mounted on top of a camera or on a boompole, or studio applications where you need to isolate a sound source, such as foley work.
Los micrófonos de cañón como el RØDE NTG5 son otro tipo de micrófono de condensador, típicamente utilizados en aplicaciones de filmación y grabación en exteriores.
This makes them ideal if you’re after a simple, all-in-one solution for recording audio into your computer as there is no need for any extra equipment, such as an audio interface or mixer, and you generally just need a single cable to get up and recording. Most USB mics even feature a headphone output for directly monitoring your recording or for playback from your device.
USB condenser microphones like the NT-USB Mini offer a simple solution for recording professional audio straight to a computer, tablet or smartphone.
Most microphones can be put to work in a wide range of situations, but some will flourish where others flounder due to their inherent traits. Let’s take a look at some of the key advantages when comparing condenser microphones to dynamic mics more generally.
As we’ve touched on, condenser microphones utilise a super-thin membrane as their diaphragm, which has a lower mass and is more responsive to sound pressure. As a result, they produce a more accurate representation of the sound source with lower self-noise, a wider frequency response, and better transient response (meaning fast-attack sounds like percussive hits and string plucks will be picked up more accurately).
Because condenser microphones feature an internal preamplifier circuit, they have a stronger output than their dynamic counterparts, meaning they require less gain from an audio interface or mixer to achieve a good recording level.
Another benefit of their design is that condenser microphones are more forgiving than dynamic alternatives when it comes to the proximity between the mic and your sound source. A condenser microphone will be able to pick up the sound more consistently and from further away than a dynamic mic, in turn resulting in a more balanced recording.
Most commonly, condenser microphones are used in the studio where their superior frequency and transient response, as well as their lower self-noise, are great for capturing clean, high-fidelity recordings that are true to the sound source.
While their increased sensitivity makes them more susceptible to picking up unwanted background noise, this is less likely to occur in a soundproofed studio. Similarly, the relative fragility of their design (at least, when compared to dynamic mics) isn’t as much of an issue in a controlled studio environment, nor is the possibility of unexpectedly loud sounds that could result in distortion in a recording.
Con su excelente respuesta transitoria y de frecuencia, el NT1-A es perfecto para grabar guitarra acústica.
Si bien no existen reglas estrictas sobre qué instrumentos o fuentes de sonido debes grabar con un micrófono de condensador, tienden a sobresalir en situaciones donde deseas capturar cada detalle de la fuente con precisión. Son extremadamente versátiles y típicamente lo que llamarías un micrófono "todoterreno", ya que pueden usarse en una amplia variedad de aplicaciones de grabación, desde voces y palabra hablada hasta guitarra acústica y eléctrica, baterías, piano y más.
Aunque los micrófonos de condensador son útiles en una amplia gama de situaciones, hay algunos casos comunes donde los micrófonos dinámicos son una mejor opción. Si tu entorno de grabación carece de aislamiento acústico o si hay muchos sonidos competidores presentes (por ejemplo, en un escenario de actuación en vivo), la mayor sensibilidad de los micrófonos de condensador significa que pueden captar estos sonidos no deseados. En estos escenarios, un dinámico puede ser más adecuado.
Si planeas manipular el micrófono o moverte durante la grabación, un dinámico a menudo será mejor, ya que son menos propensos a captar ruido de manipulación, aunque en algunos casos esto se compensa con montaje de choque, como con los micrófonos de cañón.
Los micrófonos de condensador también suelen ser más frágiles que los dinámicos, por lo que no son ideales en situaciones de grabación donde es probable que experimenten mucho movimiento o manejo brusco (aunque hay algunas excepciones, como los micrófonos de cañón y condensadores diseñados específicamente para actuaciones en vivo, como el RØDE M2).
El RØDE M2 es un micrófono de condensador profesional y resistente, diseñado específicamente para actuaciones en vivo.
If the sound source you’re recording has the possibility of getting unexpectedly loud, then condenser microphones may not be ideal as they can distort at high volumes due to their sensitive nature and also may overload the input of your recording device due to their higher output level.
If you’re looking for a great condenser microphone, either large- or small-diaphragm, the RØDE range offers loads of excellent options for any recording application, including studio mics, on-camera mics, shotgun mics, live performance mics, USB mics and more.