Home Recording Series Vol 4 – Microphone Placement Basics
Following on from our home recording issue on microphones, we will now be exploring the basics of microphone placement. Both the microphone you select and where it is place have an impact on the overall tone and quality of your recording. The following article is intended to help a beginner achieve good results quickly. This being said, microphone placement is extremely subjective and depends greatly on the end result you are looking for. However, the better or more appropriate your microphone placement, the easier it will be to mix.
The most logical way to begin considering your microphone placement is to look at the source you’re recording. Here are some common examples to get you started:
Vocal Microphone Technique
Condenser microphones are the most common choice for studio vocals. There wide frequency response, smooth sound, and natural tone allow the subtle nuances of the human voice to be captured. To avoid unwanted mouth and breath noises, place the microphone 20 – 30cm from the vocalist. The distance will also help avoid overloading the capsule, which causes distortion and reduced clarity.
If you’re finding the sibilance on your recordings too harsh (that’s the “S” sounds), you might consider positioning your microphone slightly above the singers mouth. By not singing directly in-front of the capsule, the high frequencies will gently roll off, and hopefully reduce harsh sibilant “S” sounds.
Pop filters – P, T, D, and B sounds produce a gust of air and can distort the capsule. Consider using a pop filter to reduce these sounds. They also help vocalists keep their distance from a microphone more consistent.
Acoustic Guitar Microphone Technique
For an instrument with lots of high frequency detail, such as the acoustic guitar, a condenser microphone is usually the best choice. Typically, a small diaphragm condenser works well due to it’s natural sound, however good results can also be achieved with a large diaphragm condenser. Placing the microphone directly infront of the sound hole will create a bass heavy boomy sound, and will often pickup unwanted hand movements. A better, more balanced result can be achieved using a single microphone positioned somewhere between the soundhole and the neck. You should also leave an adequate distance to avoid accentuating unwanted fret noise and hand movement – somewhere between 1 and 2 feet should do it.
A single microphone works well when placing acoustic guitars in a busy mix of instruments. However, in sparse acoustic compositions, you can achieve more interesting results with a stereo pair of small diaphragm condenser microphones. One aimed at the body and the other at the neck (12th fret), will produce a well balanced and open sound. For more low end, you might also consider a large diaphragm condenser at the body paired with a small diaphragm condenser on the neck.
Electric Guitars/Bass Microphone Technique
When recording an electric guitar/bass cabinet, you must first establish where the speakers are located. Many cabinets will contain more than one speaker cone, but in general – moving the mic towards the edge of a speaker cone will result in a duller sound, while moving the mic closer to the centre will produce a brighter tone. The centre contains the most bite or presence and will help cut through a dense mix.
Using a unidirectional microphone introduces the proximity effect – explained in Vol3. Anyhow, in-short – placing the microphone very close will increase low frequencies, while placing the microphone further away will reduce bass and increase room ambience.
Dynamic microphones are often preferred for electric guitar applications, due to their handling of high sound pressure levels. If you prefer the brighter characteristics of a condenser microphone, you might want to consider using a -10db pad – if the microphone has one.
Piano Microphone Technique
Recording a piano can be challenging and there are numerous techniques and approaches, but for the purpose of this blog, we will be covering the basics. Typically, a stereo pair of small diaphragm condenser microphones are the best choice. The lid should be open to achieve the best results and it’s worth experimenting with omni-directional microphones for a more natural sound. As general good practice, try placing the microphones approximately 30 – 60 cm above the strings – one aimed at the low strings and the other at the high strings. The closer the microphones, the more accentuated the attack and hammer noise will be. This technique provides a great starting point, but it’s important to experiment and move the microphones subtlety to find the “sweet spot”. Moving the mic’s just a few centimeters can change the sound dramatically.
Drum Microphone Technique
Drum kits are one of the most complicated instruments to record and although there are many approaches, some basic and common techniques should be understood. It is best to consider each part of the kit as a different instrument – each with their own frequency range and tonal characteristic, but it’s also import to consider isolating or separating each piece as must as possible.
Bass Drum: Typically, the microphone is placed inside the bass drum using a boom arm and placed a few inches away from the beater head. The closer you get to the beater head, the more attack you will pickup and experimenting with this distance to find a “sweet spot” will result in the perfect low end/attack balance.
Specialised kick drum microphones such as the beta52 are recommended for a bass drum, as they have good low frequency response with a boosted attack.
Snare: To capture the attack and rattle of a snare, it is best to mic it from the top and bottom. Each mic should be placed at the edge of the drum, approximately 2 – 7 cm away, and angled toward the centre. Using a unidirectional microphone will reduce spill from other drums, however, be careful not to pickup the hi-hat when using a super-cardioid microphone.
Toms: Use a similar approach to the snare drum. Dynamic or condenser microphones can be used for toms and snares – a condenser will usually deliver more attack.
Overhead: Using a stereo pair of condenser microphones will capture the stereo image and also capture the cymbals at a consistent level. Typically, each microphone is pointed at the cymbals – i.e, one over the ride, and the other over the crash. However, it is worth considering the 3 to 1 rule for the best phase coherence:
The Three To One Rule - The 3 to 1 Rule is a multiple microphone placement rule that helps prevents the pickup of one microphone from interfering with another. The rule is: Two microphones, intended to pick up two sound sources must be placed apart at least three times the distance that either microphone is from it’s intended sound source.
Drums in more detail
Recording drums is a detailed operation, and much too in-depth for this particular blog. You can find more detail on mastering drums from stage to studio at Shure’s Drum Mastery website.
In this blog, we have covered some of the basics to get you started, with such a short guide it is impossible to cover every instrument in great detail. Nevertheless, it is important to experiment. Each instrument and recording environment is different. Invest some time in trying different mic positions next time you record, and as a general rule of thumb – if it sounds good, it is good.
Join us for volume 5, where we look at the recording environment. Subscribe to our RSS feed to be alerted. In the meantime, for more information on home recording products by Shure visit the home recording microphone page.