I have written software for calculating the effects of equalization filters on loudspeaker responses. It uses the Asymptote graphics software to plot and to calculate filter responses.
Asymptote Software
Here is an example using my LX521.4 speakers. First I measured the speaker response with REW (1/6 Octave averaging) and exported the measured response curves. Then I plotted the curves with my software and added additional equalization. In addition to the two (L and R response curves) files from REW the input to the program was a file that defined the plot -
xmin=20
xmax=20000
ymin=0
ymax=100
y2min=-200
y2max=200
title=LX521.4 Magnesium Cone Base Equalization
filename=LX521.4_Mg_Base_Equalization
draw_phase=0
remove_jumps=0
xlab=$f\textrm{ Hz}$
ylab=$\left | H \right | \textrm{ dB}$
y2lab=$\phi\textrm{ deg}$
pltR=R Jun 27.dat,freq,amp,phase
pltL=L Jun 27.dat,freq,amp,phase
and a file that defined the added equalization (filters) -
*Filter freq gain Q
equal1=pk 7000 6 2
equal2=pk 150 4 1
The output is -
Then I add the tweaks to the miniDSP Flex 8 dsp/crossover I use for the LX521.4. Measured the output with REW again (1/6 Octave averaging) and plotted the results with my program.
I wondered if anyone would find this of interest. So far the filters available are peaking, low and high shelf, low and high Butterworth and Linkwitz Riley. Asymptote is included with the MiKTeX and TeX Live installations.
LaTeX
Asymptote Software
Here is an example using my LX521.4 speakers. First I measured the speaker response with REW (1/6 Octave averaging) and exported the measured response curves. Then I plotted the curves with my software and added additional equalization. In addition to the two (L and R response curves) files from REW the input to the program was a file that defined the plot -
xmin=20
xmax=20000
ymin=0
ymax=100
y2min=-200
y2max=200
title=LX521.4 Magnesium Cone Base Equalization
filename=LX521.4_Mg_Base_Equalization
draw_phase=0
remove_jumps=0
xlab=$f\textrm{ Hz}$
ylab=$\left | H \right | \textrm{ dB}$
y2lab=$\phi\textrm{ deg}$
pltR=R Jun 27.dat,freq,amp,phase
pltL=L Jun 27.dat,freq,amp,phase
and a file that defined the added equalization (filters) -
*Filter freq gain Q
equal1=pk 7000 6 2
equal2=pk 150 4 1
The output is -
Then I add the tweaks to the miniDSP Flex 8 dsp/crossover I use for the LX521.4. Measured the output with REW again (1/6 Octave averaging) and plotted the results with my program.
I wondered if anyone would find this of interest. So far the filters available are peaking, low and high shelf, low and high Butterworth and Linkwitz Riley. Asymptote is included with the MiKTeX and TeX Live installations.
LaTeX
