Ricardo Pereira
 
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The Analogue Era

The idea of recording sounds and music became a reality at the end of the 19th century. In 1877, Thomas Edison invented the first sound-recording mechanism practical for commercial use. Edison's device consisted of a phonograph that used a wax cylinder, about five to six inches long, and utilized a recording technique called hill-and-dale. In the decade that followed the invention of the phonograph, other recording devices were created such as a flat recording disc of wax-coated cardboard by Alexander Bell, Chichester Bell and Charles Tainter, and the disc phonograph by Emile Berliner (Mumma et al [no date]).

The first recording devices were used mainly for communications, business, stenography, telegraphy and entertainment to some extent. Berliner was the first to use his recording device for entertainment and cultural purposes.
Berliner's machine would become the standard method of commercial disc recording until the introduction of the stereophonic recording in the 1950s (Ibidem).

In 1898, Valdemar Poulsen demonstrated the principle for magnetic recording in his telegraphone. However, it wasn't until the advent of electronic amplification that the musical potential of this technique could be realised. In 1947, the Ampex Corporation, produced the first high quality magnetic recorder for studio use in the USA. The main advantages of tape over the disc phonograph were the relative ease of editing and the substantially lower cost (Ibidem). 

Around this time, some important changes occurred in the area of disc recording with the development of polyester plastics, called polyvinyl chloride (PVC) or "vinyl", which had a smaller grain structure than shellac (of which 78 r.p.m. discs were commonly made). Vinyl discs allowed the recording of a wider range of frequencies and dynamics, and suffered considerably less from surface noise. The new discs gave better fidelity and were less fragile than the previous ones (Ibidem).

The arrival of the vinyl led to the fixing of new standard speeds for recording and playback. In 1948 Columbia introduced the 331/3 r.p.m. “long-playing” disc which allowed up to 25 minutes of music on each side. The 12 inch, 331/3 r.p.m, quickly became standard replacing multiple-disc albums of 78 r.p.m. The 45 r.p.m., 7-inch “single”, replaced the 78 r.p.m. “single” disc (with a similar playing time of two to four minutes). Two variants of the 45 r.p.m. disc would be introduced such as the 7-inch EP (two tracks on each side, running for twice as long as single) and the 12-inch single that had a playing time of 12 minutes per side (Ibidem).

A decrease in the cost of materials, manufacturing, and distribution made these discs more affordable than before. The use of easily edited magnetic tape also improved the efficiency of the record companies’ operations. These factors led to the expansion of the recording industry.

In 1957 the recording industry introduced stereophonic discs. The technique of stereophonic (stereo) recording and playback produces the effect of sound coming from different directions in a three-dimensional space. 
This technique could only be developed after the invention of the two-track magnetic tape. The reason behind it is that in order to create this effect, two channels have to be recorded and played independently. On a microgroove disc the two channels are recorded as independent variations in the left and right walls of a V-shaped groove (Picture on the right). Although some stereo recordings were made in the 1930s, this technique only became relevant with the introduction of the vinyl discs (Mumma et al [no date]; Ghassaei 2012) .

Two-track tape introduced a new recording practice that became know as multitrack recording. This process involves the simultaneous or consecutive synchronized recording of multiple tracks. Each track usually carries a single instrument. At first, recording a song using this technique used to take a lot of time. Once the two-track tape was introduced, two tracks could be recorded in one tape; these two tracks could then be bounced into one track of a second two-track tape; the process could then be repeated until the song was finished. New types of magnetic tape that could support more tracks and new analogue mixing console would then be introduced. Up to 24 tracks could then be recorded on tape, up to two inches wide. Some studios were able to offer 48-track recording by linking two 24-track consoles (Sound City 2013; Mumma et al [no date]). Multitrack recording allowed the artist to record in one of the tracks while listening to some of the tracks previously recorded. 



One of the great advantages that recording on tape brought was the possibility to manipulate audio as a physical entity; this could be done by cutting the tape at the required point and rejoining it to another section of tape, using adhesive tape or sometimes glue. This technique was called splice and in order to avoid any unwanted noise, the cut should be made at an angle so that any click introduced by the cut was spread over a few milliseconds (Mumma et al [no date]). 



One of the most famous analogue mixing consoles is the Neve 8078 and is considered by many experts unique. The characteristic Neve sound has featured in numerous hit records including Neil Young, Fleetwood Mac, Cheap Trick, Fear, Tom Petty and the Heartbreakers, Santana, Rick Springfield, Nirvana, Rage Against the Machine, Queens of the Stone Age, Metallica, Johnny Cash, Kings of Leon. All these artists recorded some of their albums in Sound City Studios located in LA, California (Sound City 2013).

In 1966, Philips introduced the stereophonic compact cassette and the machine on which it could be used. The compact cassette consisted of a sealed case containing a miniature reel-to-reel tape. By 1980 albums were issued in two formats: disc and cassette (Mumma et al [no date]).

The Digital Era

In the mid-1970s the recording industry started to employ digital technology for recording. Digital recording techniques use digital technology in combination with analogue techniques or instead of these. In the early 1980 a new format was introduced, the compact disc. This medium was based entirely on digital recording and playback technology. Discs recorded by analogue methods were unable to reproduce the sound with accuracy at the extremes of the frequency range and the contact between the surface and the stylus created surface noise during playback. Digital recording aimed to solve these problems. By the mid-1980s music had started to be released in compact disc and a few years later the compact disc would end up replacing the 12-inch disc (Ibidem).

The full range of human hearing is between 20Hz and 20kHz therefore, according to the sampling theorem, the minimum sample rate that satisfies these conditions is 40kHz. That is why a digital recorder sampled the sound signal 44,100 times per second (frequency of 44,1 kHz). Nowadays technology already allows recording at higher sample rates. The most common ones in digital audio are 48 kHz, 88.2 kHz, 96kHz and 192kHz (Self, D. 2012; Ellert).

In its first years the compact disc used 16-digit codes for recording and playback. 16-bit technology allowed nearly 66,000 possible timbres. The industry later on introduced 20-bit recording (more than 1 million possible timbres) and 24-bit recording. These recording formats would then have to be translated into 16-bit format for playback (Mumma et al [no date]; anon. [no date]).

One of the advantages of the compact disc and digital formats is that the stored signal never loses its original sound quality and can be copied many times with no audible change. A compact disc allows a standard playing time of 74 minutes but discs with a maximum playing time of 81 minutes can be issued. In 1999 two formats emerged: the DVD, used for digital video, with the capacity to support surround sound; and the Super Audio CD, that utilizes a faster and simplified type of sampling which more closely approximates an analogue sound wave and offer a maximum playing time of 110 minutes (ibidem).

There are different formats in which a song can be saved on our computers. Some of the most common formats are WAV, AIFF and MP3 (compressed format). iTunes and similar platforms that sell music online allow people to purchase music in a digital format, where people no longer have a physical copy of the album. In the last few years, platforms like YouTube and more recently Spotify introduced streaming. Streaming means listening to music or watching video in ‘real time’ instead of downloading a file into the computer and watching it later (WebWise Team 2012). Spotify allows the user to pay a monthly subscription that gives him permission to listen to unlimited music (spotify website).

Digital technology has brought changes not only in terms of the formats but also in terms of mixing consoles. Digital mixing desks were introduced and computers started to replace magnetic tape for recording. At first the computers were slow and the simple process of bouncing a song could take a couple of hours (Sound City 2013). Nowadays this is not a problem any more and software like Pro Tools, Cubase, Logic Pro made things much easier. It is now possible to edit and mix a song much more quickly and small imperfections in songs can be easily fixed. With the introduction of Digital Audio Workstations (DAWs) recording a song is no longer a problem and creating a “home studio” is something accessible to a lot of people.  Editing also became a non-destructive process, as computers should retain a copy of the original recording (Inglis 2011; Anon. [no date]). Pro Tools also made possible quantizing sound with its Elastic Audio tool.

Digital technology revolutionized the recording industry and introduced new ways of recording. An artist no longer needs to be a good musician and be ready to go into a recording session in order to record a song. One of the advantages of Analogue Recording is the need for a band to be tight and ready to record a song. Analogue methods made a musician interact and play with other creative minds, developing their music and skills. Then they would go in the studio and there was something magical when a band was getting recorded and managed to play the whole song for the first time. The feel captured in these situations by tape is something extraordinary. Analogue mixing desks have their own sound because of their components and the way they are built, and there is no doubt that a mixing desk can be responsible for the sound in an album (Sound City 2013).

One of the disadvantages of tape is the price. Because the demand has gone down, the prices have gone up. Maintaining an analogue console can be quite expensive. What a lot of people that love the analogue sound might do is record some elements, like drums, and then transfer it to digital (Liljeblad [no date]).

A lot of people, engineers and musicians still love the imperfections associated with analogue signal processing and the bleeding generated by some analogue components (Cooper 2004). These factors associated with the human feel, passion and skill are some of the reasons why we still find early recordings from the 50s, 60s and 70s so exciting and inspiring.

 
References

-    Anon. [No date]. [Online]. Available from:
     http://www.bbc.co.uk/learningzone/clips/recording-sound-analogue-vs-digital/5977.html
     [Accessed 3 May 2013].

-    Cooper, P. 2004. Is analogue mixing superior to digital summing?. [Online]. Available from:
     http://www.soundonsound.com/sos/jun04/articles/qa0604-5.htm
     [Accessed 3 May 2013]

-    Elert, G. [No date]. [Online]. Available from:

     http://hypertextbook.com/facts/2003/ChrisDAmbrose.shtml
     [Accessed 3 May 2013].


-    Ghassaei, A. 2012. 3D Printed Record. [Online]. Available from:
     http://www.instructables.com/id/3D-Printed-Record/
     [Accessed 5 May 2013].


-    Ghassaei, A. 2012. Step 1: How does a record work?. [Online]. Available from:
     http://www.instructables.com/id/3D-Printed-Record/
     [Accessed 5 May 2013].

-    Mumma, G., et al. [No date]. Recording. In: Kernfeld, B, ed. The New Grove Dictionary of Jazz. 2nd ed. 

     Oxford Music Online. Oxford University Press. [Accessed 29 April 2013].

-     Inglis, S. 2011. Audio Editing in DAWs. [Online]. Availble from:
      http://www.soundonsound.com/sos/feb11/articles/editing-1.htm
      [Accessed 3 May 2013].

-     Liljeblad, U. [No date]. Digital vs. Analogue – Recording. [Online]. Available from:
      http://www.mix-engineer.com/audio-philosophy/digital-vs-analog-recording/
      [Accessed 26 April 2013].

-     Self, D. 2012. Audio Engineering Explained. Taylor & Francis US.

-     Sound City. 2013. Music Documentary. Directed by Dave Grohl. Roswell Films.

-     WebWise Team. 2012. What is streaming?. [Online] Available from:
      http://www.bbc.co.uk/webwise/guides/about-streaming
      [Accessed 3 May 2013].



 
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Miking up a drum kit can be one of the most time consuming and frustrating instruments to record. There are several ways to record drums, from using only one microphone to using one or more microphones in each drum component. 

If we want to record the drums with only one microphone we should use a large diaphragm condenser microphone set to cardioid polar pattern. This kind of microphone gives us clarity and the high frequency response required to record the cymbals and hi-hat. The mic should be placed over the kick drum pointing at the snare drum. Although the microphone is set to the cardioid pattern and is focusing on the snare drum, there is enough spill from the rest of the kit that enables the microphone to pick all the other drum components. If the condenser mic has a -10dB attenuation  switch, it should be switched on in order to avoid distortion in the sound. 
http://www.youtube.com/watch?v=iS_YZpn818A

Although miking up the whole kit with only one mic is a much quicker process, it is worth spending some time miking up the whole kit as this will produce the best results. The choice of microphone and its position will define the sound of each component. In order to capture a natural drum kit sound, we can use a high quality condenser mic positioned overhead, in front of or behind the kit. The mics used for this purpose include the Neumann U87and KM84, the AKG C414B and C451. Usually the overheads capture enough cymbal sound therefore it won’t be necessary to mic the cymbals individually. 
 
To record the bass drum we want a robust microphone that will have a great low frequency response. The AKG D112 is a large diaphragm dynamic microphone and is specially designed to record the kick drum. If the front head of the kick drum has been removed or if it has a large enough hole in it, the mic should be placed inside close to the beater head about halfway between the centre and the edge. In addition to this microphone we can use another dynamic microphone further away from the beater head. Trying different positions of the mics is always a good idea in order to get the best sound.

Although the snare drum can be recorded with a condenser microphone like an AKG C451, the most common approach is using a dynamic mic like the Sure SM57. When using an SM57 we get a fatter and bigger sound than when we use a condenser. It is also much easier to control the signal as dynamic mics are less sensitive. It is a good idea to use two mics on the snare: one on the top; and one below to capture the sound created by the rattle. The mic on the top should be placed near the edge because a fuller range of overtones is present in this area. This approach also minimizes the changes of it getting it. The microphone positioned below the snare should be placed about 20 cm away from the rattle halfway between the edge and the rattle. When using a mic below the snare, its polarity should be switched to the opposite polarity of the one on the top.

Usually there is enough hi-hat sound captured by the overheads but we can mic it up individually for better clarity and control. To record the hi-hat we can use a small diaphragm condenser mic, placing it about 10-15cm over the outside edge of the hi-hat. The mic should be perpendicular to the the hi-hat pointing down. In order to avoid the sound created by the snare the mic should be placed on the side that is furthest away from the snare. 
  
In order to mic up the tom-toms we can use a similar approach to the one used on the snare drum with dynamic mics positioned over the rim pointing to the centre of the head. The rear of the mic should be angled up to reject the sound produced by the cymbals (note that the cymbals radiate sound in a figure of eight pattern above and below the metal plate). In terms of microphones we can use a dynamic microphone like the Sennheiser E604.  

Here is a video that shows some of the approaches mentioned above for miking up a drum kit
http://www.youtube.com/watch?v=TD1_SwHEs4A&feature=related
For more information click on the following links:
http://www.soundonsound.com/sos/feb03/articles/drummiking.asp
http://www.soundonsound.com/sos/jul99/articles/recordingdrums.htm
http://www.soundonsound.com/sos/aug10/articles/drum-tuning.htm

 
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Recording an acoustic guitar is a complex task and there are a lot of different factors that we should have in mind before recording. First of all we must choose an acoustic guitar that suits the song as two different guitars can have very distinctive sounds. As mentioned in a precious blog, it is important to use new strings when recording guitars and tune the guitar before each take.

If the acoustic guitar has a pickup that is always one advantage as it could add some colour to the sound. If the guitar doesn’t have one it is good idea to use a piezzo pickup and place it in different parts of the guitar to try to get the best sound. Miking up an acoustic guitar always produces better results. Although we can use an SM 57 to record an acoustic guitar that is not the best approach. Condenser mics are much
more sensitive and pick up much more high frequency detail. 
 
Purists will usually pick a small-diaphragm condenser microphone for its greater high frequency accuracy. In terms of polar pattern, the cardioid pattern tends to suit smaller rooms better whereas omni-pattern mics would be better in larger rooms with natural reverb and better acoustic characteristics. 

The position of the microphone is crucial when recording. In live situations for example, it is normal to see the mics placed very close to the sound hole of the acoustic guitar because the main concerns are level, separation and the avoidance of feedback. When we are recording acoustic guitar we need to have a totally different approach. It is true that when we play the acoustic guitar most of the sound energy comes directly out of the sound hole. However, the sound we hear is coloured by the body resonances of the guitar. Therefore, if the mic is used too close to the guitar, the direct sound produced by that part of the guitar will be more dominant. This is an important concept to have in mind when recording with more that one mic.
    
If we are using only one microphone, the most common approach is to set up a mic around 40cm from the guitar, aiming it at the point where the guitar’s neck joins the body. This will usually produce a well-integrated and balanced sound as the levels of direct and reflected sound will be about right and the sound coming from the sound hole won’t be too strong as the mic is not pointing directly at it. 

If we are using more than one mic, we should keep the condenser microphone at the position mentioned before and place other mics around. If we place a microphone over the musician’s shoulder, this will produce a sound similar to the sound we hear when we play the guitar. We can also place a microphone pointing to the neck of the guitar but the best thing is exploring and placing the mic in different places until we find the best sound.

For more information about recording electric guitar please read the following articles:
http://www.soundonsound.com/sos/aug01/articles/recacgtr0801.asp
http://www.soundonsound.com/sos/apr10/articles/acguitar.htm
http://www.soundonsound.com/sos/apr10/articles/acguitaudio.htm (examples of different recordings)


 
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Recording vocals is a very complex process as a good vocal sound can make the difference between an average and a great song. The most used microphones for vocal recording are condenser microphones. However, dynamic microphones are commonly used when recording vocals for trash metal or other genres that include screaming. If you are recording live with a band and you don’t have access to an isolated room for vocal recording, it is a good idea to record vocals with a dynamic microphone and overdub the vocals later on using a condenser mic.

Considering that you are ready to record vocals, there are a few factors you should think of. The position of the microphone is one of them. It is important to place the mic away from the walls. You should also try to avoid placing the microphone in the centre of the room as the sound waves are usually in phase at this location, which tends to exaggerate the room resonances. In order to reduce popping it is a good idea to use a pop shield between the singer and microphone. It should be placed around 10 cm from the microphone.

Most large-diaphragm microphones have its own shockmount suspension, which can be extremely effective in reducing unwanted noise. This kind of suspension is used to isolate the microphone from the stand reducing the amount of noise cause by mechanical vibrations. 

In terms of polar pattern, most sound engineers use the cardioid polar pattern as it is more sensitive to sounds  coming from the front than from the back. When recording, it is a good idea to use an analogue compressor. This helps evening the signal levels and could avoid some distortion in some loud parts of the song. You should avoid using an EQ during the recording process. Usually the EQ is added during the mixing process.

For more information about recording vocals check the following links:
http://www.youtube.com/watch?v=pnwj3xkhErE (basic techniques)
http://www.youtube.com/watch?v=OMv30qxamN0 (polar paterns)
http://www.soundonsound.com/sos/jun01/articles/vocalsfaq.asp
http://www.soundonsound.com/sos/oct98/articles/20tips.html


 
Recording bass guitar is slightly different from recording electric guitar. Although we can record electric guitars using a DI and use some plugins to change the sound of the guitar, such practice is more common when recording bass. A well-played and well-recorded bass is vital to the sound and feel of a track; therefore it is vital to choose the right sound and best recording technique.

The first thing that we need to do is decide how to record the bass. We can mike up the amp, record it through a DI or combine these two techniques. When recording it through a DI, we are recording the natural sound that the bass is producing. Therefore, we will need to use some plugins to get the sound we want, as well as a compressor, limiter and an EQ. If we want to mike up the amp we are playing through, we can use a dynamic microphone, a condenser microphone or both. If we are using a dynamic microphone it is a good idea to use an SM57 or an AKG D112, usually used to record the bass drum. As explained in the previous blog, Recording Electric Guitar, the position of the microphone influences the sound we get. Therefore, if we want to enhance the low frequencies a good idea is to place the microphone close to centre of speaker.  If we want to give some colour to the sound of the bass we can use a condenser microphone. This will add some brightness to our sound. When using this type of mic, it is important to have the -10dB switched on so that the sound doesn’t distort.

It is common to split the signal miking up the amp we are using, at the same time that we are recording it through a DI. Some amps have a DI that we can use. If that is not the case, we can use an external one.
It is a good idea to use an analogue compressor if we are recording music that includes slapping, such as funk. This will even the signal and avoid big differences in the level of the sound.

To find out more about recording bass click on the following links:
http://www.youtube.com/watch?v=8CEDwn9JTiE
http://www.soundonsound.com/sos/mar99/articles/recordingbass.htm


 
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Nowadays there are many different ways to record electric guitars. There are three different aspects we need to think of when recording electric guitars: the instrument itself, the amplifier and the loudspeaker system used. These components will all contribute to the sound of our electric guitar. When miking techniques are taken into consideration there are other variables that will contribute to the sound of our recording. 
 
Although there is a number of effective DI techniques to record electric guitars, the traditional method is to mic up a really good amplifier. As far as the mic is concerned the amplifier is the instrument and therefore the position of the mic is really important. A lot of
sound comes from the speakers but there is also sound emitted from the back and sides of the amp. Both capacitor and dynamic microphones can be used to record electric guitar. Dynamic microphones produce a solid sound, while capacitor microphones produce a brighter, more open sound when used in the same way.  

When it comes to positioning the mic, the most common approach is to place the microphone very close to the speaker grille, pointing directly at the centre of the speaker. The closer it is to the centre the toppier the sound is. If we move the mic to one side it sounds less trebly and more bassy. Miking the back of the amp usually produces a warmer and less bright sound than miking from the front. The effect that the position of the microphone has in the sound is more noticeable when using a dynamic microphone. In order to get a better sound, an ambience microphone is often used. The type of microphone used to capture the ambience in the room is usually a condenser microphone which should be placed several feet from the cabinet. This will add a natural sense of space to the sound. 
 
 Some engineers combine these techniques by positioning two mics close to the amp (one on-axis and one off-asix) and a distant mic. Using different microphones close to the amp, a capacitor and a dynamic will give us a greater choice of tonality. When mixing, we can use delay on the ambience in order to increase its effective distance from the amp. Each millisecond of delay is equivalent to 12 inches of distance. 

To read more about recording electric guitar read the following article.
http://www.soundonsound.com/sos/Dec02/articles/recordingguitars.asp
 It is also worth reading the following article as there are a lot of important tips that we should consider when we are recording electric guitar.
http://www.soundonsound.com/sos/aug98/articles/20tips.html
In the following video we can listen to how the sound of the electric guitar changes with the position of the
microphones.
http://www.youtube.com/watch?v=9k5BqSXUR6E


 
All microphones convert sound energy into electrical energy, however there are different ways of doing it, such as piezo-electric effects, electromagnetism or electrostatics. In music recording or live performance, the majority of mics are either capacitor/condenser (electrostatic) or dynamic (electromagnetic) models. In both models, there is a sensitive diaphragm that is moved by the energy in a sound wave. However, the principle behind each model is different.

In the dynamic microphones, there is a diaphragm that is attached to a very small coil of wire suspended in the field of a permanent magnet. A sound then causes the diaphragm to vibrate, which makes the magnet move, inducting an electrical signal. The whole assembly works as a very small generator that produces a very small electrical signal. As the output is too small, it has then to be amplified using a mic preamp.

Dynamic microphones are the most used in live performance, and in the studio these mics are also usually used to record instruments such as drums, electric guitar and bass. These mics have the advantage of being relatively inexpensive, robust and they don’t need a power supply to make them operate.  One disadvantage of these mics is its poor high frequency response.

A condenser microphone works slightly differently from a dynamic.  There is a pair of plates, one fixed and the other in the form of a moving diaphragm. When the diaphragm vibrates the space between the plates changes and the capacitance varies. When a fixed electrical charge is applied to the capacitor and the capacitance changes, an electrical sign is produced. That is why all condenser microphones need a 48V phantom power source in order to operate. This operating system makes capacitor microphones much more sensitive, efficient and capable of capturing high frequency detail much more accurately.

Capacitor microphones are usually more expensive than dynamic microphones and are usually used for acoustic instruments, vocals and cymbals. They are also used to record electric guitars combined with dynamic microphones, or to record the ambience in a room.

Microphones have different polarities such as cardioid (only pick the sound from one side), omni (picks the sound from all around the microphone) and figure of 8 (picks the sound from two opposite sides of the microphone). To know more about types of microphones please read the article Choosing a Microphone: Types & Uses, published on Sound on Sound's website, by Paul White.
http://www.soundonsound.com/sos/1995_articles/jun95/microphones.html