With the rapid advances in technology and the ever increasing scale and quality of games and films its no surprise that capturing audio cannot simply be pointing a microphone at an object, the need for high end resolution such as 24/96 resolution and 7.1 surround sound will become standard in the near future. for this reason its essential that I have a firm understanding of spatial recording and surround sound techniques.
Graded unit Development: SPP 2:
A large part of sound production and my future ambitions in sound design involves recording my own sample library,. for this reason it will be important for me develop a good understanding of micing techniques learned SPT2 and to apply knowledge in a real world setting. Another important part of this module is to have a firm understanding 5.1 surround sound and use this in a practical setting.
There are two examples two recording sessions which i will use as an example of my experience in microphone and stereo techniques.
1. A 3 minute recording of guitar with three stereo micing techniques decca tree, mid side and blumlein. in this example I will give a comparison of the mics weight there advantages and disadvantages.
2. A 3 minute home recording with the Sontronics STC-10 and 3X.
Recording in G/21
through careful consideration myself, david and martin decided to record in g/21. The reason for this being is well sealed booth allow for recording bliss without the worry of background noise. The carpeted surfaces, temporary walls and reasonably high ceiling allow prevents over saturation of reverb. This area is ideal especially considering how sensitive condenser and omni directional mics can become.
Here is the following equipment list during the recording session:
Channel 1: Centre
Channel 2: Left Omni Directional
Channel 3: Right Omni Directional
Channel 1: Cardiod
Channel 2: Bi Directional
Channel 1: Bi Directional
Channel 2: Bi Directional
Edirol 4 channel portable recorder and wave editor.
Rode NT2000 x 2
XLR cables x3
Recorder settings: 4x mono, 44kHz, 24 bit.
an example of a decca tree used in the G/21 Recording booth, omni directional mics are position to 2 metres apart on the side and 1 metre apart in the front.
Despite the fact that the decca is normally used for orchestra or choir performances the decca tree is especially useful in larger environments, this is normally due to the decca tree’s wide stereo image.
After further analysis of the recordings I can conclude that although the decca tree is a great stereo micing technique. The decca tree is able to provide a proper surround experiences and able to capture subtle audio such as the tambourine. The recording of the guitar came in to faint lacking the strong string quality im looking for in an acoustic guitar
This is my personal favourite. The mid side stereo mic is built positioning the bi directional mic( bottom mic) 90 degrees off axis from the sound source and the cardioid mic (top mic) pointing directly at the sound source. I have often preferred the micing technique as it provides more options over the width of the stereo spread and versatile as it allows changes to made post recording.
While listening to the mastered down M/S recording I noticed quite good qualities to the recordings. M/S offered a far stronger and ambient which not surprising considering that M/S allows for further adjustments while editing on Sonar 8.5.
In retrospect M/S was positioned a little bit too much to the centre but as it was able to capture the tambourine in the background proved that the recording was more than adequate.
The recording was not 100% however as there was delay in playing the guitar, however this can easily be fixed in Sonar 8.5.
The Blumlein Pair
both bi directional mice are placed 45 degrees on opposing ( left and right) sides of the sound source
A Blumlien Stereo micing technique:
While recording with the Blumlein pair we noticed the stereo imaging was very similar to what can naturally be heard with human hearing, the guitar recording also came out far sharper than and relatively no ambience in the recording than that of the mid side ( probably due it’s mono compatibility and the coincident placement of the two mics.).
with further comparison I chose both mid side and blumlien to be suitable recording techniques and will later go on to the surround sound stage.
Here is a list of the following used:
Logbook Entry from 4/05/2014
Project Name: William Recording 40514
Use Mid Side Micing Technique in order to produce a 5.1 Stereo Recording.
Alesis I02 Express
2 XLR Cables
Pro Tools 11
AKG Semi Closed Headphones
Sonotronics STC-10 Condenser Microphone
Results from Today:
Recording ran rather smoothly, although the mic stand had a habit of becoming top heavy. This meant I had to hold the mic stand for the majority of the recording.
The Mid Side Technique was placed in four recording location, positions at or behind the bridge of the guitar. Top left, top right, bottom left and bottom right.
Clipping Issues was present but quickly fixed with minor mic placement adjustments and reducing the gain on the audio interface.
As Sonar 8.5 was not present on site The tracks were panned to there appropriate positions with pro tools stereo tracks. i.e. top left mic position panned to the top left.
The stereo mix will now be bounced at the following specs: 44.1 kHz, stereo interleaved, 24 bit and converted to a WAV file format.
Now that both mic techniques it’s now time to go to the 5.1 surround sound for testing and editing with the following:
Cakewalk Sonar V studio console 700
for the mid side I kept to the standard procces of double tracings , then panning the mid mic to the centre and the side mi being split into two equal channels, then pan hard left and hard right.
For Blumlien pair was double tracked panned positioned to focus on the front centre, front left and front right.