Hello everyone, especially John Mulcahy, Angelo Farina and Antonin Novák.
I wanted to say my thanks for the inspiration of my bachelor’s thesis in electrical engineering, which goes by the title "Evaluation of the “Exponential-Sine-Sweep” measurement for visualizing nonlinear systems in Matlab".
I had the simultaneous luck and misfortune to have to choose my own topic for my thesis. So I laid eyes upon one of the most burdensome topics in electrical engineering - nonlinear characteristics of dynamical systems. My supervising professor was instantly put off with remarks of never hearing about nonlinear convolution methods. Though he was certainly interested in exploring the topic nonlinearities of systems further, in order to expand his own lectures in digital signal processing. He had to curb my enthusiasm a little bit, as I was wildly imagining being able to incorporate nonlinear dynamic models as guitar amp sims on DSP-Chips. Oh boy, I was in over my head. Nevertheless my professor and I came to the consensus, that I could write a Matlab program or a series of scripts, which he then could include in his masters-degree program.
In the midst of all these discussions stood my childlike wonder how one could not only measure a linear impulse response, but on top of that, how you could get a distortion graph simultaneously. I mean, linear frequency response? Easy! Do a pulse, a step or even a sweep and transform the response to the frequency domain. It sounds complicated and it kind of is, when you haven't had lectures on system control in engineering school. The gist of it is that you do not need the lectures to understand the basic concept - we hear everything in terms of frequencies! Back to Room Eq Wizzard - I was really dumbfounded on how it could be possible to measure higher harmonic order frequency responses with just one sweep. On the surface it is an easy concept, if you can imagine that every sinewave excitation of a nonlinear system inevitably produces harmonic content – one sinewave in, many overlapping sinewaves out. But how do you implement that? How do you modulate the frequency? How do you extract harmonic content, if the excitation frequency constantly modulates? I eventually found my way to John Mulcahys sources. I hope I am not wrong if I pose that the exponentially swept sine method is the heart of Room Eq Wizzard. I want to say thank you to John for making this really useful and complicated piece of software (REW) accessible. Having written something similar (kind of) in Matlab makes you appreciate how well thought out REW is. I also want to say thank you to Angelo Farina and Antonin Novák for making their research publicly available.
For anyone interested, I am not yet ready to post my thesis online or make it available for everyone. As of now, I am self-conscious about the shortcomings of my thesis. It is a little misguided due to the negligence of my supervisor. It is a really complicated topic and I do not think I was able to do it justice, not to my own satisfaction.
Thank You John
Thank You Angelo
Thank You Antonin
And thanks to everybody who preceeded this research
Here is an interesting measurement of the Darkglass Alpha-Omega Ultra V1 distortion unit:
I wanted to say my thanks for the inspiration of my bachelor’s thesis in electrical engineering, which goes by the title "Evaluation of the “Exponential-Sine-Sweep” measurement for visualizing nonlinear systems in Matlab".
I had the simultaneous luck and misfortune to have to choose my own topic for my thesis. So I laid eyes upon one of the most burdensome topics in electrical engineering - nonlinear characteristics of dynamical systems. My supervising professor was instantly put off with remarks of never hearing about nonlinear convolution methods. Though he was certainly interested in exploring the topic nonlinearities of systems further, in order to expand his own lectures in digital signal processing. He had to curb my enthusiasm a little bit, as I was wildly imagining being able to incorporate nonlinear dynamic models as guitar amp sims on DSP-Chips. Oh boy, I was in over my head. Nevertheless my professor and I came to the consensus, that I could write a Matlab program or a series of scripts, which he then could include in his masters-degree program.
In the midst of all these discussions stood my childlike wonder how one could not only measure a linear impulse response, but on top of that, how you could get a distortion graph simultaneously. I mean, linear frequency response? Easy! Do a pulse, a step or even a sweep and transform the response to the frequency domain. It sounds complicated and it kind of is, when you haven't had lectures on system control in engineering school. The gist of it is that you do not need the lectures to understand the basic concept - we hear everything in terms of frequencies! Back to Room Eq Wizzard - I was really dumbfounded on how it could be possible to measure higher harmonic order frequency responses with just one sweep. On the surface it is an easy concept, if you can imagine that every sinewave excitation of a nonlinear system inevitably produces harmonic content – one sinewave in, many overlapping sinewaves out. But how do you implement that? How do you modulate the frequency? How do you extract harmonic content, if the excitation frequency constantly modulates? I eventually found my way to John Mulcahys sources. I hope I am not wrong if I pose that the exponentially swept sine method is the heart of Room Eq Wizzard. I want to say thank you to John for making this really useful and complicated piece of software (REW) accessible. Having written something similar (kind of) in Matlab makes you appreciate how well thought out REW is. I also want to say thank you to Angelo Farina and Antonin Novák for making their research publicly available.
For anyone interested, I am not yet ready to post my thesis online or make it available for everyone. As of now, I am self-conscious about the shortcomings of my thesis. It is a little misguided due to the negligence of my supervisor. It is a really complicated topic and I do not think I was able to do it justice, not to my own satisfaction.
Thank You John
Thank You Angelo
Thank You Antonin
And thanks to everybody who preceeded this research
Here is an interesting measurement of the Darkglass Alpha-Omega Ultra V1 distortion unit:
