diff --git a/DSP/Assignment_2_report/U1265119_Assignment2_report.tex b/DSP/Assignment_2_report/U1265119_Assignment2_report.tex index 615c50e..ca2ec25 100644 --- a/DSP/Assignment_2_report/U1265119_Assignment2_report.tex +++ b/DSP/Assignment_2_report/U1265119_Assignment2_report.tex @@ -89,13 +89,13 @@ \item D/A \& A/D converters \end{itemize} - In order to understand the specification of the dsPIC in relation to the - standard of DSPs available, it will be compared to three other digital signal - processors: + In order to understand the specification of the + dsPIC~\parencite{mt2004dspic} in relation to the standard of DSPs + available, it will be compared to three other digital signal processors: \begin{itemize} - \item Texas Instruments TMS320F2806 - \item Freescale 56F8025 - \item Analog Devices ADSP-2126 + \item Texas Instruments TMS320F2806~\parencite{ti2016pm} + \item Freescale 56F8025~\parencite{fs2006dsc} + \item Analog Devices ADSP-2126~\parencite{ad2012adsp} \end{itemize} \subsection{General Computing Factors} @@ -217,8 +217,8 @@ of calculations must be performed in a set period of time in order to process audio as quickly as it is provided to the system. If the clock speed is not sufficient, this may result in instructions being missed due - to an interupt before the processor has been able to complete them. This - can create in artefacts in output audio.~\parencite[p.34]{sd2006mfes} + to an interrupt before the processor has been able to complete them. This + can create artefacts in output audio.~\parencite[p.34]{sd2006mfes}\\ It should be noted that this is not an entirely accurate measurement for speed as different manufacturers have different definitions of a @@ -277,7 +277,7 @@ performance. Variations of this have been used in all examples. \section{DSP Specific Factors} - DSP specific factors relate to components specically affecting the system's + DSP specific factors relate to components specifically affecting the system's ability to handle audio signals. These will determine the quality of audio manipulation and affect the computational requirements for the system. This section briefly covers the computational impact of the DSP specific @@ -360,11 +360,10 @@ menu button. Parameter variables can then be increased and decreased for the selected effect using two switches.\\ It was not possible to use the UI in conjunction with any actual audio - effect as proper threading of the menu alongside the DSP process was not - possible. Having the menu run in the same thread as signal processing - forced menu logic to complete at signal rate. When this did not occur this - would create unexpected results and graphical error in the LCD as logic was - not completed fully. As a result, the project presented is a prototype to + effect as the UI would need to be processed after any audio effects. in + practice this caused problems as the program did not always have time to + complete UI logic before the interupt, causing graphical errors and + unexpected results. As a result, the project presented is a prototype to demonstrate possibilities given a capable system. \section{Results} @@ -386,18 +385,35 @@ equally simplistic results in terms of perception. A feedback was not implemented to differentiate this from the reverb design. + \subsection{Chorus} The implementation provided a perceptually similar alternative to the - infeasible modulated delay line design from the previous assignment. + infeasible modulated delay line design from the previous assignment. Each delay can be set to up to a maximum delay time of 250 samples. This allows for manual shifting of phases to taste. Overall this results in a functional alternative at the cost of perceptual quality. + Through the use of a spectrogram, it can be seen in figure + \ref{fig:cho_spec} that the signal is clearly noisy and distorted with + harmonics produced far above the nyquist rate. This is most likely due + to the poor converter performance + \begin{figure}[H] + \caption{Chorus spectrogram displaying distortion} + \makebox[\textwidth]{\includegraphics[width=\textwidth]{Chorus_spectrogram}} + \label{fig:cho_spec} + \end{figure} \subsection{Reverb} A crude slapback reverb was created using an FIR/IIR filter combination. The result was a short reverb tail with decaying repetitions of the dry sample. This would have been vastly improved with the addition of further parallel comb filters or all pass filters. + A clear decaying echo can be see in figure \ref{fig:rev_wav} + + \begin{figure}[H] + \caption{Reverb waveform} + \makebox[\textwidth]{\includegraphics[width=\textwidth]{Click_reverb_waveform}} + \label{fig:rev_wav} + \end{figure} \section{Further Work} Building on skills learnt in this project, results could be improved diff --git a/Experimental_Music_Assignment_2/proposal/EM2_Assign2_Proposal.tex b/Experimental_Music_Assignment_2/proposal/EM2_Assign2_Proposal.tex new file mode 100644 index 0000000..eb7c890 --- /dev/null +++ b/Experimental_Music_Assignment_2/proposal/EM2_Assign2_Proposal.tex @@ -0,0 +1,180 @@ +\documentclass{scrartcl} +\usepackage{enumitem} +\usepackage[british]{babel} +\usepackage[style=apa, backend=biber]{biblatex} +\DeclareLanguageMapping{british}{british-apa} +\usepackage{mathptmx} +\addtokomafont{disposition}{\rmfamily} + +\addbibresource{~/PerryPerrySource/LaTeX/ExperimentalMusic_Bibliography.bib} +\DeclareCiteCommand{\citeyearpar} + {} + {\mkbibparens{\bibhyperref{\printdate}}} + {\multicitedelim} + {} + +\begin{document} + \title{Experimental Music\\Formative Assignment 2\\Essay Proposal\\} + \author{Sam Perry\\U1265119} + \subtitle{The role of electronics, feedback and amplification in + experimental music composition.\\} + \date{} + \maketitle + + \section{Essay Objectives} + This essay will explore the ways in which prominent composers utilise + electronic devices and systems to compose music; focusing primarily on + feedback and amplification as techniques for creating and manipulating + sounds in both the analog and digital domain. This will provide a detailed + overview of these widely used processing techniques, and will explore the + reasons behind their popularity amongst experimental composers. The + advantages and disadvantages of using these techniques will be explored in + detail with regards to established concepts, and the aesthetics of such + effects. + + \section{Subject Rationale} + Electronics have played a key role in the development of experimental music + in the past fifty years and have had a dramatic effect on the ways in which + experimental music is realised. The ability to control amplitude and cause + feedback has influenced a number of compositions, which will be explored in + this essay.\\ + Examples of compositions include: + + \begin{enumerate} + \item \textbf{Acoustic Feedback} + \begin{itemize} + \item Steve Reich's Pendulum Music~\parencite[p.31]{reich2002wom} + \item Robert Ashley's The Wolfman~\citeyearpar{ashley2003w} + \end{itemize} + + \item \textbf{Electronic Feedback} + \begin{itemize} + \item David Tutor's Untitled ~\citeyearpar{tudor1996twfle}, + Toneburst ~\citeyearpar{tudor2004lem}, and + Pulsers ~\citeyearpar{tudor1996twfle} + \item Gordon Mumma's Hornpipe~\citeyearpar{mumma2002lem} + \end{itemize} + + \item \textbf{Amplification} + \begin{itemize} + \item John Cage's Cartridge Music~\citeyearpar{cage2013cm} + \item Stockhausen's + Mikrophonie~\citeyearpar{stockhausen1995mmt} + \end{itemize} + \end{enumerate} + + \section{Areas of Interest} + The areas that will be explored in detail in this essay include: + + \begin{enumerate} + \item \textbf{Types of amplification and feedback}\\ + This will discuss the different variations of the techniques based + on the development of technology and the implications of these + variations. + + \begin{enumerate}[label*=\arabic*.] + \item \textbf{Analog feedback}\\ + Referring to the use of a microphone and loudspeaker to + generate an amplified feedback loop of sounds in the cross-over + field between the two.~\parencite[p.185]{holmes2012eaem} + + \item \textbf{Tape feedback}\\ + Referring to the technique of recording input to a tape and + looping over a playhead to produce repetitions in the output + signal. Used by Robert Ashley in "The + Wolfman".~\parencite[p.186]{holmes2012eaem} + + \item \textbf{Electronic feedback}\\ + An alternative to tape feedback which works entirely + electronically, where a signal is ``generated within an + electronic instrument whose design enables the recirculation of + a signal within a closed circuit''. + ~\parencite[p.187]{holmes2012eaem} This technique features heavily + in David Tudor's works. + ~\parencite{tudor1996twfle, tudor2004lem} + + + \item \textbf{Feedback manipulation}\\ + The delay in time between a direct signal and a feedback signal + allows for the manipulation of repetitions. This gives scope + for a wide range of possible manipulations to the overall + output and is explored in pieces such as Gordon Mumma's + ``Hornpipe''. ~\parencite[p.390]{holmes2012eaem} + + \item \textbf{Digital feedback}\\ + With the growing use of computers for musical processing, + feedback is possible in the digital domain, as it is in the + analog domain. This allows DSP techniques to be applied to + feedback loops leading to significant advancements in effects + such as artificial reverb, giving even further scope to the + possibilities for composers. + + \item \textbf{Artificial Amplification}\\ + Amplification is an important part of any feedback system as it + allows for control over both initial input and the feedback + loop. It also allows for ``small + sounds''~\parencite[p.6]{cage2011silence} to perceived at much + higher volumes than they naturally occur. This is explored in + John Cage's ``Cartridge Music'' and Robert Ashley's ``The + Wolfman''. + + \end{enumerate} + \item \textbf{Reasons for interest in these techniques} + \begin{enumerate}[label*=\arabic*.] + \item \textbf{Indeterminacy}\\ + Due to the ``exponentially complex patterns of information flow + in feedback networks''~\parencite[p.11]{weisert2010ioi}, + feedback adds an element of indeterminacy to composition. The + build up of audio on each repetition causes varying and often + unpredictable effects in the output + sound.~\parencite[p.100]{nyman1999em} This will be compared to + other techniques for introducing indeterminacy (such as John + Cage's use of the I Ching). + + \item \textbf{Rhythmic/Temporal implications of feedback}\\ + Feedback allows for the repetition of a sound source over an + extended period of time. This has implications rhythmically that + can be controlled by the composer. The level of signal feedback + will determine the decay and repetition of a signal and can + create infinite loops of a single source sound. The + implications of this will be discussed with reference to + compositions such as Alvin Lucier's ``I am sitting in a + room''.~\parencite[p.57-59, 64-68]{weisert2010ioi} + + + \item \textbf{Dynamic implications of artificial amplitude + adjustment}\\ + Both directly and as part of a feedback system, artificial + amplification will change the perceived level of the input + sound. This allows composers to artificially boost or attenuate + sound in compositions and, in conjunction with a feedback loop, + control feedback decay. This will be discussed with reference + to many of the compositions discussed above (this is used to + varying degrees across practically all previously discussed + compositions.) + + + \end{enumerate} + \item \textbf{Forms of control} + \begin{enumerate}[label*=\arabic*.] + \item \textbf{Process and systems}\\ + Due to it's unpredictable nature, feedback can be difficult to + control and can produce unexpected results. Composers have used + a variety of methods to structure and control feedback as part + of their compositions.~\parencite{weisert2010ioi} These + processes will be explored to understand the different methods + for structuring compositions when composing using feedback. + \end{enumerate} + \end{enumerate} + + \section{Potential Issues} + The area of feedback in experimental music has a greater depth than + initially anticipated (as does amplification). This essay may focus more + heavily on feedback than amplification although both will be discussed as + they are intrinsically linked. This may need more thought when planning the + essay.\\ + Further refinement of areas may also be needed to focus on the most + important aspects of the subject. This will become clear through writing + the first draft. + \printbibliography +\end{document} diff --git a/Experimental_Music_Assignment_2/proposal/Notes_for_essay.txt b/Experimental_Music_Assignment_2/proposal/Notes_for_essay.txt new file mode 100644 index 0000000..632865d --- /dev/null +++ b/Experimental_Music_Assignment_2/proposal/Notes_for_essay.txt @@ -0,0 +1,18 @@ +Notes for Essay: + +Systems: + +- Use of electronics for the creation of "systems": + + why this is interesting for composers? + The use of "sonification" in computer music allows for the bypassing of + symbolic musical notation, instead opting to drive musical events + through use of other data types (such as arbritrary weather information + for example) + This allows composers to distance there own discourse from the creation + of music, relinquishing control to the data to greater degrees than is + easily acheiveable through acoustic music.~\cite[p.129]{mclaughlin2011dsma} + +- Not bound by the limitations of human performance or the timbres of +traditional instruments~\cite[p.351]{holmes2012eaem} + diff --git a/Hud_masters_proposal/Sam_Perry-Research_masters_proposal.tex b/Hud_masters_proposal/Sam_Perry-Research_masters_proposal.tex index a02d337..c075233 100644 --- a/Hud_masters_proposal/Sam_Perry-Research_masters_proposal.tex +++ b/Hud_masters_proposal/Sam_Perry-Research_masters_proposal.tex @@ -8,6 +8,29 @@ \restylefloat{table} \usepackage{perpage} \MakePerPage{footnote} +\usepackage{graphicx} +% Create hyperlinks in bibliography +\usepackage{hyperref} + +\newsavebox{\abstractbox} + +\usepackage{etoolbox} +\makeatletter +\expandafter\patchcmd\csname\string\maketitle\endcsname + {\vskip\z@\@plus3fill} + {\vskip\z@\@plus2fill\box\abstractbox\vskip\z@\@plus1fill} + {}{} +\makeatother + +\DeclareCiteCommand{\citeyearpar} + {} + {\mkbibparens{\bibhyperref{\printdate}}} + {\multicitedelim} + {} +\usepackage[T1]{fontenc} +\usepackage[utf8]{inputenc} +\usepackage{blindtext} +\setkomafont{disposition}{\normalfont\bfseries} \addbibresource{~/PerryPerrySource/LaTeX/Hud_masters.bib}