Microphone Comparison (Electric Guitar)

Different microphones have distinct sound characteristics that can significantly alter amplified sound. Therefore, choosing an appropriate microphone is crucial. As part of a project at Hochschule Düsseldorf, these sound characteristics were systematically compared in relation to electric guitar sounds to determine the effects of different microphone on recorded sound.

Condenser Microphones operate on the electrostatic principle, which allows for the conversion of sound waves into electrical signals. The essential component of this microphone technology is the condenser capsule, which consists of two charged plates: a stationary backplate ("counter electrode") and a movable diaphragm. When sound waves strike the diaphragm, the distance between the plates changes, thereby affecting the capacitance of the capacitor. This change in capacitance generates an electrical signal.

Condenser microphones are characterized by their wide frequency response and are known for their high sensitivity. This feature enables them to capture the finest nuances and details of a sound with exceptional precision. Another advantage of these types of microphones is their typically low self-noise, meaning they can record quiet sounds with remarkable clarity. However, it is important to note that condenser microphones generally require an external power source, which is often provided in the form of a battery or phantom power, to operate the condenser capsule.

Dynamic Microphones are based on the electrodynamic principle. The basic structure consists of a vibrating diaphragm that is connected to a coil. This coil is situated within the magnetic field of a permanent magnet. When sound waves act upon the diaphragm, the coil moves within the magnetic field, generating an electrical signal according to the law of induction. This signal usually needs to be significantly amplified, as dynamic microphones tend to produce relatively low output voltages.

Dynamic microphones are characterized by their ability to handle high sound pressure levels, making them ideal for loud sound sources such as guitar amplifiers. Due to their construction, they are also particularly robust and resistant to background noise and vibrations. Typically, they do not require an external power source, as they generate the output voltage through the movement of the diaphragm itself.

Ribbon Microphones represent a special class of microphone technologies based on the ribbon principle. They are almost always pressure gradient transducers. The basic structure of a ribbon microphone consists of a very thin metal ribbon that is precisely positioned between the poles of a magnetic field. When sound waves strike the ribbon, it moves within the magnetic field, inducing an electrical voltage. This generated voltage is then output as an electrical signal. However, ribbon microphones produce such low voltages that an internal transformer is usually required to step up the signal by a factor of about 30.

Ribbon microphones are characterized by their delicate sound reproduction, which arises from the fact that the ribbon is not mechanically tensioned, is extremely lightweight, and can easily follow the air movements when sound waves hit it. It should be noted, however, that ribbon microphones generally exhibit a more limited frequency response compared to other microphone types, resulting in a "midrange" sound. Due to their mechanically sensitive ribbon diaphragm, ribbon microphones should be protected from strong air blasts, slamming doors, or plosive sounds to avoid damage.

The following microphones were compared as representatives of their respective operating principles:

Using a reamping box, a pre-recorded dry DI signal was played back through a Fender Super Twin amplifier with settings appropriate for the genre. The various microphones were placed in the exact same position one after another to ensure a highly accurate comparison. A short electric guitar sample, belonging to the funk genre, was played through the Fender Super Twin.

The distance of the microphones from the amplifier was 4 cm.

The distance from the center of each microphone to the edge of the speaker cabinet was measured at 15 cm. This ensured that the position of the microphone relative to the speaker cone was consistent for all recordings.

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The following tone settings were made on the Fender amplifier:

To make the differences between the microphones comparable, the individual recordings were analyzed using the plugin "Fabfilter Pro Q3," and the results were presented graphically. The level differences in the frequency spectrum of the recordings with the various microphones can be seen.

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Shure SM57

The Shure SM57 is a well-known dynamic microphone that is often used for recording electric guitars. It stands out due to its boost in the mid/high frequency range (up to 5 kilohertz) and a steep drop for even higher frequencies, resulting in a sound that is very bright but not harsh, making it well-suited for electric guitars and percussion.








Sennheiser E604

According to the manufacturer, this microphone is designed to handle high levels of up to 130 dB. For this reason, low-level signals are represented with less dynamics. It may therefore be better suited for heavily distorted and loud signals. However, it is rarely used in the context of electric guitars. Its preferred application is with percussive instruments, such as toms.







AKG C414 EB

The AKG C414 EB is a classic, well-known large-diaphragm condenser microphone. Thanks to its dual diaphragm technology, the polar pattern can be switched. This allows for the use of the proximity effect, which results in a boost in low frequencies, making it well-suited for jazz recordings, for example.








Sennheiser MKH 800

This microphone is a five-position switchable condenser microphone that also features a multi-stage switchable pad, low-cut filter, and high boost. In this setup, no attenuation, reduction, or boost was applied. The polar pattern was set to cardioid. The frequency response in this setting is virtually linear, allowing for very precise recording of all types of signals. This is helpful when no alteration of the sound is desired in the recording due to the microphone.






Royer R-121

Due to its physical characteristics, the ribbon microphone is tuned to the mid-range, resulting in warmer recordings. Similar to the Shure SM57, it clearly represents mid to high frequencies, while a gentle roll-off in the high end avoids a harsh, aggressive sound. For this reason, it can be interesting for many genres.









Literatur:  Weinzierl, Stefan: "Handbuch der Audiotechnik", 1. Aufl. Springer Berlin, Heidelberg, 2008, ISBN 978-3-540-34300-4