In this post, we will take a closer look at condenser microphones. For an overview, please refer to the previous document
Link to Condnser and Dynamic microphones document
Contents
Tube (Vacuum Tube) Condenser Microphones
Tube microphones are perceived as high-end microphones. Of course, not all tubes are automatically good, but there are definite advantages that tubes can offer. The characteristics of vacuum tubes can be broadly classified into four categories. Let’s take a closer look.
1.High BIAS Voltage
High BIAS voltage allows for a wider headroom. Bias voltage refers to a constant voltage used to set or adjust the operating state of certain electronic devices or components. Having a high Bias voltage increases the headroom, allowing the audio signal’s maximum amplitude to be handled more substantially. This has the effect of reducing distortion.
Tube microphones do not use 48V phantom power. Due to the operating characteristics of tubes, they require a higher voltage. Therefore, a separate phantom power supply is needed, and this is why the BIAS voltage is also high.
2. Soft Clip
Due to the characteristics of vacuum tubes, soft clipping occurs at moments of high volume. This is different from hard clipping and does not result in a harsh sound.
This soft clipping characteristic helps to smoothly handle sudden changes in the signal or distortion. Therefore, even signals that exceed the officially stated Max SPL (Maximum Sound Pressure Level) can be handled smoothly, effectively providing a wider headroom.
3. Tube Saturation
Tube Saturation Provides a Rich Timbre.
Due to the nature of vacuum tubes, they induce even harmonics, as opposed to odd harmonics. This results in a timbre that is not sharp but rather smooth and rich. Additionally, the peak levels do not decrease, which means there is significantly less distortion.
4. Slow slew rate
The Slow Slew Rate Results in Smooth Transient Expression.
Slew Rate represents the maximum speed at which the output of an operational amplifier or other circuit can change dramatically. In simple terms, it measures how quickly a circuit can respond.
From another perspective, a slow slew rate is smooth, but it can also be interpreted as having less effective transient response.
FET (Field Effect Transistor) Condenser Microphones
1.Low BIAS Voltage
They have relatively low BIAS voltage, as they are powered by 48V phantom power, as mentioned above. Consequently, their headroom is also comparatively narrow.
2. Hard Clipping
Unlike vacuum tubes, peaks at high volumes in FET microphones result in hard clipping, which tends to produce a harsher sound quality.
3. Odd Harmonics
Odd number harmonics occur, and unlike even harmonics, they possess a sharp and rough characteristic.
4. Fast Slew Rate
With a relatively fast Slew rate, the transient response tends to be better compared to vacuum tubes.
Handheld Condenser Microphones
Condenser microphones are known for their high sensitivity, making them challenging to use in live environments. However, apart from studio recording, there are also handheld versions of condenser microphones specifically developed for live performances on stage.
1. Flat Frequency Response
Handheld condenser microphones typically boast a flatter and broader frequency response (especially in the ultra-high frequencies) compared to most dynamic microphones. This means they can capture sound more naturally and with greater detail. Such characteristics are ideal for accurately reproducing the nuances of voices or instruments in live stage performances.
2. Super-Cardioid Pattern
In a stage environment, the performance of a microphone can be affected by ambient noise and sounds from other instruments. For this reason, super-cardioid microphones are often used on stage, and handheld condenser microphones typically possess this pattern.
This means that the microphone primarily responds to sound coming from the direction of the user’s mouth, and blocks out sounds coming from other directions.
3. Lower Input Sensitivity
Handheld condenser microphones generally have a lower input sensitivity compared to other condenser microphones. For example, the Neumann KMS105 has a sensitivity of 4.5mV/Pa. This lower sensitivity reduces the risk of feedback, offering a significant advantage for stage use.
For these reasons, they can be considered suitable for home recording environments that do not have professional booths.