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Acoustic measurements of the audio system.


This section contains a plethora of acoustic measurements made with an IBM T20 laptop with a crystal DVD chipset soundcard, A lapel microphone with panisonic mic element, using various software programs:
ETF v 5
ETF v 4
SpeakerWorks v9
Cooledit 2000
Spectrogram
Microcap v6
The measurements are a snapshot in time, of an evolving system. The measurements were recorded in the listening room, with the microphone at the listening location, unless otherwise noted.
The bare bones text will be updated at the end of the next month.


(click image to see larger version) The frequency response, Speakerworks program



(click image to see larger version) The frequency response, white noise, FFT via CoolEdit2000



(click image to see larger version) The Impulse response.



(click image to see larger version) The waterfall response.



(click image to see larger version) The impulse response, broad time scale.



(click image to see larger version) The impulse response zoom time scale.



(click image to see larger version) The low frequency response, windows with increasing time delay, another form of waterfall.



(click image to see larger version) The mid frequency response, windows with increasing time delay, another form of waterfall.



(click image to see larger version) The high frequency response, windows with increasing time delay, another form of waterfall.



(click image to see larger version) The low frequency waterfall plot



(click image to see larger version) The mid frequency waterfall plot



(click image to see larger version) The high frequency waterfall plot



(click image to see larger version) The room decay curves



(click image to see larger version) The room decay curves



(click image to see larger version) The RT60 decay curve



(click image to see larger version) The 1/3 octave response



(click image to see larger version) The psuedo anechoic response



(click image to see larger version) The phase response



(click image to see larger version) The phase response low frequency zoom



(click image to see larger version) white noise excitation, system frequency analysis



(click image to see larger version) white noise excitation, system frequency analysis, zoom db scale



(click image to see larger version) white noise excitation, system frequency analysis



(click image to see larger version) Spectral view of impulse response



(click image to see larger version) Energy - Time - Frequency plot



(click image to see larger version) Energy - Time - Frequency plot



(click image to see larger version) Waterfall frequency response, Heyser transform



(click image to see larger version) Waterfall frequency response, Heyser transform



(click image to see larger version) Waterfall frequency response, Heyser transform



(click image to see larger version) Waterfall frequency response, Heyser transform



(click image to see larger version) The pseudo anechoic frequency response, Heyser transform



(click image to see larger version) The low frequency response , Heyser transform



(click image to see larger version) Harmonic distortion, low frequency



(click image to see larger version) Harmonic distortion, mid frequency



(click image to see larger version) Low frequency harmonic distortion as a function of amplitude, both channels



(click image to see larger version) Mid frequency harmonic distortion as a function of amplitude, both channels



(click image to see larger version) Frequency response comparison, one woofer vs. two woofers driven.



(click image to see larger version) Waterfall frequency response comparison, one woofer vs. two woofers driven.



(click image to see larger version) Frequency response comparison, Altec vs. commercial sub.



(click image to see larger version) Distortion comparison, Altec vs. commercial sub.



(click image to see larger version) Ultra low frequency distortion graph, altec transmission lines



(click image to see larger version) Distortion graph



(click image to see larger version) Distortion graph



(click image to see larger version) The schematic diagram of my preamp - active filter - bass boost circuit



(click image to see larger version) The modeled frequency response of the preamp - active filter - bass boost circuit



(click image to see larger version) The schematic diagram and modeled frequency response of 1st order 6db/oct high level speaker crossovers midrange to tweeter, including summed response.



(click image to see larger version) The schematic diagram and modeled phase response of 1st order 6db/oct high level speaker crossovers midrange to tweeter, including summed phase response. Note zero phase distortion through xover region



(click image to see larger version) The schematic diagram and modeled frequency response of my second order xovers, that mimic 1st order crossover phase performance but have 2nd order speaker protection. including summed response. Note NEAR zero phase distortion through xover region



(click image to see larger version) The schematic diagram and modeled phase response of my second order xovers, that mimic 1st order crossover phase performance but have 2nd order speaker protection. including summed response.



(click image to see larger version) Comparison, 1st and 2nd order xovers



(click image to see larger version) Comparison, 1st and 2nd order xovers



(click image to see larger version) Speaker cabinet modelling



(click image to see larger version) Listening room modal analysis



(click image to see larger version) Predicted vs. measured room modes



(click image to see larger version) Predicted vs. measured room modes



(click image to see larger version) Compairson of transmission line frequency response, with and without bass boost.



(click image to see larger version) The low frequency phase performance



(click image to see larger version) modeled response of JBL 10" drivers in vented box



(click image to see larger version) The Altec transmission line speakers without bass boost



(click image to see larger version) The Altec transmission line speakers in room with bass boost



(click image to see larger version) The Bullock simulated response for the altec 4m transmission lines



(click image to see larger version) details of the tractrix tweeter horn shape



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