By applying the same technique as being used to produce the other measurement curves......
I do understand why you want to use so many drivers, you want them to operate at a very smal band so they perform at an optimum. But do you realise how many other "problems" you get back with such a setup?
See it like this:
a fullrange driver is chosen by many people for their coherent sound and imaging.
Other people trade this for a broader frequencyresponse and less distortion they get with a multi-way system.
Your system is actually a multi-way system but then overdone, it makes no sense to me, sorry.
See it like this:
a fullrange driver is chosen by many people for their coherent sound and imaging.
Other people trade this for a broader frequencyresponse and less distortion they get with a multi-way system.
Your system is actually a multi-way system but then overdone, it makes no sense to me, sorry.
12 drivers makes perfect sense IMO, but not 12 way speakers.
4 woofers, 2 midwoofers, 2 low midranges, 2 upper midranges, tweeter and ambience tweeter.
I`d have accepted nothing less than such a ruler flat response from a design of this gauge.
Unless the dent in the lower part of the curve (need a better circle) pretty nice even polar response too: all the same curve for 15 Hz, 300 Hz, 800 Hz, 2 kHz, 5 kHz, 9 kHz and 15 kHz, just as expected for a 12-way with drivers randomly placed all over the baffle
And the fact that the "universal" polar curve for one speaker is an exact mirror for the other, including every little glitch, is only proof of the perfection of matching between the two systems. Only a cynic would suggest that someone had drawn a polar curve and flipped it for the opposite speaker!
David S.
Well one would expect that when he is showing only one speaker in the two pictures.
I was assuming he had achieved equal perfection in the mirror image matching of his cabinet veneers!
Are we really supposed to believe that not only is the speaker flat to within a dB down to below 30 but there are absolutely no room effects to add any of the usual room signature to the curve?
I've read his design theory. He has designed textbook crossovers from some simple 4th order network formulas. He picked components based on the calculated values to an extreme precision. The formulas take no regard for the drivers as loads. No simulation was done to see how multiple octave bandpasses might add. Driver delay due to depth is not considered. Polar responses are "ideal" for all frequencies, in spite of the random driver layout.
Driver levels were equalized by measuring each section in issolation at the center of the bandpass. The added padder resistence was not considered in the network simulations (it would change Q). The high pass and low pass proximity with octave wide filters was not considered (the nearby corners would interact). In fact the equations are for independent lowpass and highpass sections but then he switches to an interleaved bandpass topology, it isn't clear if he changes the math after that.
And now we are seeeing near perfect response and polar curves?
Come on Cal, clearly this is a charade!
David S
And then I came across this while looking for measurement software;
"This essentially perfect behavior of the first order filter pair once led me to use them for a 13-way crossover I designed for a consulting client in the recording industry. Yes, I said 13-way!"
-John L. Murphy on the True Audio site; Multiway crossover design
Anyone want to simulate and/or speculate on that?
"This essentially perfect behavior of the first order filter pair once led me to use them for a 13-way crossover I designed for a consulting client in the recording industry. Yes, I said 13-way!"
-John L. Murphy on the True Audio site; Multiway crossover design
Anyone want to simulate and/or speculate on that?
Well, with your background in math and electronics
, it must be obvious to you that parallel 8th order bandbass filters (4th order highpass + 4th order lowpass) add 360 degrees of phase rotation in the summed acoustic response for each filter. Use any software you want, the result is the same. Oh, and the pro version of LspCAD costs 1000 USD.First order filters only really make sense (to me) if you use lots of drivers to limit the bandwidth of each driver. Conversely, lots of drivers only really make sense if you use first order filters to limit the system's phase rotation.
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