Redrafted Aim and Objectives

After researching into a few different 5.1 microphone techniques and finding out about Upmixing i have refined the concept of my project.

Aim:

To create a test to assess the qualities and preference between upmixing techniques and 5.1 microphone techniques. The test will be created specifically for the techniques applications in recording live events and performances. 

Objectives:

• Research 5.1 microphone techniques and Upmixing techniques and their applications in recording live music. 

• Record and mix live events and performances using 5.1 microphone techniques and upmixing techniques.

• Compile and then analyse the results of a listening of both 5.1 and upmixing techniques.

Research into Upmixing

Upmixing is a technique used to convert mono or stereo into 5.1 surround sound. This is an interesting technique to consider in relation to my project as it could mean the possibility of not having to record the event in 5.1 but rather in stereo and then convert it to surround sound. However the upmixing does not create a "true" 5.1 image but gives it a larger sense of space by adding information to the rear speakers of the 5.1 array.

• It would be interesting to consider testing a 5.1 recording with a stereo version that has been upmixed. The results would show wether people can tell the difference between the two techniques and which one is preferred by the listener. This would indicate wether it is worth going to the expense of recording an event in 5.1 or upmix a stereo recording. 

"There are lots of ways of expanding stereo material to 5.1, but most techniques are based on those developed for converting mono to stereo. The most common approach seems to be to allocate the original stereo channels to the left and right channels of the 5.1 array, and then derive centre and surround channels. The derivation of centre and surround channels may remain unchanged throughout the track (the usual technique for classical music), or may change — perhaps to emphasise specific sections, such as the choruses in popular music. Of course, by retaining the original left and right channels, the end-user can easily get back to the original stereo if they don't like the upmixed surround version.
Techniques vary widely, but the centre channel is typically a mono sum of left and right, possibly with a little equalisation and maybe a touch of extra delay. The surrounds are usually derived from left minus right (and vice versa), again with some delay and EQ, and possibly some extra reverb. Much hushed talk surrounds the production of upmixed 5.1 mixes from stereo, but as you can see, it's not really rocket science, merely a way of arranging material from a completed two-channel stereo mix such that it plays back over all six channels of a 5.1 playback system. There are also several products on the market now — such as TC Electronic's System 6000 — which incorporate dedicated algorithms specifically to convert stereo material to 5.1. The results depend on the source material, but often the upmixed version is very credible and pleasant to listen to."

You Are Surrounded, Surround Sound Explained- Part 5, Hugh Robjohns, December 200, Sound on Sound Magazine

Research into Microphone Techniques

I have been reading an Audio Engineering Society Convention Paper which discusses 8 different surround microphone techniques used for live orchestral recordings. The paper discusses the results that were gathered from a subjective listening test where the subject could freely listen to each microphone technique which were assigned separate sliders, enabling the subject to rate the techniques simultaneously.

Audio Engineering Society Convent Paper 7233, 
Correspondence Relationship between Physical Factors and Psychological Impressions of Microphone Arrays for Orchestra Recording,
Toru Kamekawa, Atsushi Marui, and Hideo Irimajiri 
October 2007

I will be using this paper to find out what microphone techniques i should use in my project as they are being applied in a similar situation of a live performance. The 8 microphone techniques discussed and tested in this paper are:

1. Fukada Tree (Fukada) 

2. INA5 (INA)

3. Double MS (DMS) 

4. Omni+8 (OM8)
5. Decca Tree + Omni Square (DT+OSQ) 

6. Decca Tree + Hamasaki Square (DT+HSQ) 

7. Five Cardioids + Hamasaki Square (5C+HSQ) 

8. Three Omnis + IRT Cross (3O+IRT)

The subjects in the listening test (13 students and 9 recording experts) were to evaluate each microphone technique by seven different attributes:

1. Spaciousness: The width of frontal image. 

2. Envelopment: The enveloped feeling surrounded lateral and backward

3. Depth: The apparent spatial distance of the sound source from the listener.

4. Localization: The apparent location of the sound source.

5. Powerfulness: Strong or heavy impression. Opposite meaning is week or feeble.

6. Softness: Mild or silky impression. Opposite meaning is hard or harsh. 

7. Preference

The averages of the test results showed that the Decca Tree plus Omni Square (DT+OSQ) technique rated the highest on all attributes. The results also showed the Double Mid-Side (DMS) technique rated the lowest on all attributes. 

From the results in this listening test it is clear to see that the DT+OSQ was the highest rated and should be applied in my project. However this test was on recording a live performance from an orchestra with no audience, which means the space was available to them to place microphones wherever they needed to be in the room without having to compromise placement because of an audience. Unfortunately i will not be able to employ DT+OSQ technique because space will be a factor during the recording in my project and to use this technique i would have to place microphones above or in the audience, that will not be an option because of health and safety factors and i am also limited by the equipment available to me. 

Because microphone placement could be compromised by the audience and room layout of the venue during the recording process of my project i have decided to use small spaced surround arrays instead of large spaced arrays which need a large area for placement. 

The small spaced arrays that were tested in discussed in the AES Paper included the INA5, Double Mid-side and IRT Cross. The DMS technique scored very low on all attributes as well as the INA5, however the INA5 did score relatively high on Localisation. The IRT Cross technique scored relatively high on all attributes and from what i gathered from the listening test results it was the 3rd "best" after the DT+OSQ and DT+HSQ techniques in terms of it being even across all 7 characteristics. Thus i will definitely be applying the IRT Cross in my project, however i will research further into all three small spaced arrays i found in this AES Convention Paper. 

Further Research:

• Practical based research- Do some practice recordings with the INA5, DMS and IRT Cross techniques
• Research more into small spaced arrays and other 5.1 production techniques

Research Into the Psychology of "presence"

This entry will discuss a piece of literature i found using the University of Abertay's online library called "Summon":

Media psychology  "is not yet there"- Introducing theories on the media entertainment to the presence debate by Christof Klimmt, Presence. Vol. 12 No. 4, August 2003, pg. 346-359

The concept for this project is about recreating the affect of being present at a music event; in doing this i will need to think about a person's state of involvement with receptive media.

"Based on conceptualizations from the psychology of literature (cf. Groeben & Vorderer, 1988), the sociology of culture (cf. Bourdieu, 1987), and from communication research (cf. McQuail, 1985; Liebes & Katz, 1986), Vorderer (1992) differen- tiates two levels of involvement and, accordingly, two modes of reception: a distant, analytical way of witnessing the events presented by the medium (low involve- ment) and, in contrast, a fascinated, emotionally and cognitively engaged way of enjoying the presentation (high involvement)... Analytical reception requires expertise and substantial knowledge about the media content and particularly about the media form." Christof Klimmt, Aug 2003, pg. 347-348

Klimmt talks about two modes of reception, a distant and analytical way of witnessing the medium which requires knowledge about the media content/form and a fascitnated and engaged way of witnessing the medium. In reference to my project concept i will be producing a listening test of the various microphone techniques i will be using, as a way of determining which is best at recreating the event in its entirety. The test subjects will have to come from a variety of backgrounds, some with knowledge of sound reproduction and some without to produce a more accurate representation of the general public as some will have knowledge of this media form and some will not. 

"Both the state of presence and the experience of involvement include the perceptual focus on mediated information and the avoidance of stimuli that do not belong to the media offering, such as unrelated own cognitions or external cues that undermine the nonmediation experience. Ideally, involvement and presence describe states in which all perceptions, thoughts, and emotions are directed towards the media environment. For this reason, involvement could be conceptualized as one dimension of presence (cf. Witmer & Singer, 1998; Biocca, Burgoon, Harms, & Stoner, 2001) or presence could be modeled as a special case of involvement." Christof Klimmt, Aug 2003, pg. 348

In reference to my project concept and recreating the state of presence, during the listening test i will have to ensure that no other stimuli or external cues are present in the testing space to allow "perceptual focus on the mediated information". From this extract of Klimmt's article we can see that perception and involvement are strongly linked, thus to recreate a state of presence we have to ensure that the subjects involvement directed to the mediated information and no where else. 

To summarise what i gathered from Klimmt's article in reference to my project concept, i need to minimise the amount of unrelated stimuli in the testing room to ensure the subjects involvement with the mediated information is the highest it can be. Also i need to ensure that my test subjects come from a variety of backgrounds some with sound production knowledge and some without.

Draft Project Objectives

• Research surround microphone techniques which have the appropriate attributes for the use in recording live music to find out what techniques to employ in my project.

• Produce a test of these microphone techniques where the subject is assessing them in terms of presence.

• Analyse the results of the test to form a conclusion about each microphone technique's use in recording live events.

First Concepts for Research Project

My first concept for the project came to me while researching how the music industry has changed over the past years due to technological advancements that allow the public access artists work for free or at very low prices. This has resulted in a huge rise in the live music industry as the public are now more inclined to go see and experience their favourite artists performing live when their music is so easily accessible. Simon Frith 2010 (Analysing live music in the UK: findings one year into a three-year research project)

The concept I derived from the information i found out about how the music industry has changed was to be able to recreate a live event so that it could be experienced again and again. This project will be based around using a variety of 5.1 Surround Sound production techniques to record live music events and find out which best recreates the event in terms of presence/feeling of being at the original event. 

Further Research:

• What 5.1 recording techniques should i implement in the project?

• How do i rate evaluate each recording technique? Questionnaire? If so who participates in the questionnaire and how do the participants measure the level of presence?

Introduction

During the development of this honours project i will be using this blog as a way of logging the development of my ideas and the research i carry out. Throughout the project i will be analysing texts and carrying out practical based research, i will describe and evaluate all these activities.

The honours project is an opportunity to explore and research a specialist subject area within your field. This blog will describe what intrigues me about Audio and Music and how i develop my interests into an academic research based project.