Sounds Real-

You are indeed right about 'just tilting back the front face'. That can be enough to line up the acoustic centers of woofer/mid and tweeter, so that the drivers are possibly in their best positions to combine properly at your ears, no matter what crossover design is used. The high-order crossover circuits then put more and more time delay on the signal the lower and lower down the scale we go. That cannot be fixed.

And then to make the first order crossover work correctly, one must choose the correct drivers to begin with. I hope this clarifies a bit more for you.

Omsed-

You ask "though the difference between the woof and mid remain constant, there is a difference, yes? And that means that the wave launch of a transient will not be the same for the 2 drivers, correct? The are not time aligned, it would seem. Even if the sum of the outputs through the crossover point remains correct, are we not stuck with the constant time differential between the 2 drivers?

Could you tell me what I am missing? "

Yes, I agree. Again, with the right drivers, Zobels, and first-order crossover design, there will always be a time difference created by that constant 90-degree differential, a constant difference 'in degrees only' at every frequency we examine.

90 degrees is one-fourth of any sinewave's period. At a 3kHz crossover point, that wave's period is 1/3000 of a second. One fourth is 1/12000 of a second. This is the time-difference between the mid and tweeter at this frequency. If we choose 1000 Hz instead, the time difference would be three times longer, 1/4000 of a second.

I can only tell you that the math of "two waves of the same tone traveling out of phase with each other by 90 degrees" will measure and sound like one wave having no time delays. Perhaps you must do the math yourself to see this-- I certainly understand that feeling! Again, the key words to look up are "operating in quadrature".

Bombaywalla-

I apologize if I gave the wrong impression. T/S parameters are quite important, as they tell us a great deal about how the driver will perform in any box.

They just do not give the exact box size, which was the hope. The error can be 10 to 20% off of the correct box volume.

A real test box's performance is determined by listening and then measuring its impedance curve and resonant frequency, to find out the Qts and Fs. That tells us how close we came to meeting the T/S ideals with that test box. Then build another...

Best,

Roy

You are indeed right about 'just tilting back the front face'. That can be enough to line up the acoustic centers of woofer/mid and tweeter, so that the drivers are possibly in their best positions to combine properly at your ears, no matter what crossover design is used. The high-order crossover circuits then put more and more time delay on the signal the lower and lower down the scale we go. That cannot be fixed.

And then to make the first order crossover work correctly, one must choose the correct drivers to begin with. I hope this clarifies a bit more for you.

Omsed-

You ask "though the difference between the woof and mid remain constant, there is a difference, yes? And that means that the wave launch of a transient will not be the same for the 2 drivers, correct? The are not time aligned, it would seem. Even if the sum of the outputs through the crossover point remains correct, are we not stuck with the constant time differential between the 2 drivers?

Could you tell me what I am missing? "

Yes, I agree. Again, with the right drivers, Zobels, and first-order crossover design, there will always be a time difference created by that constant 90-degree differential, a constant difference 'in degrees only' at every frequency we examine.

90 degrees is one-fourth of any sinewave's period. At a 3kHz crossover point, that wave's period is 1/3000 of a second. One fourth is 1/12000 of a second. This is the time-difference between the mid and tweeter at this frequency. If we choose 1000 Hz instead, the time difference would be three times longer, 1/4000 of a second.

I can only tell you that the math of "two waves of the same tone traveling out of phase with each other by 90 degrees" will measure and sound like one wave having no time delays. Perhaps you must do the math yourself to see this-- I certainly understand that feeling! Again, the key words to look up are "operating in quadrature".

Bombaywalla-

I apologize if I gave the wrong impression. T/S parameters are quite important, as they tell us a great deal about how the driver will perform in any box.

They just do not give the exact box size, which was the hope. The error can be 10 to 20% off of the correct box volume.

A real test box's performance is determined by listening and then measuring its impedance curve and resonant frequency, to find out the Qts and Fs. That tells us how close we came to meeting the T/S ideals with that test box. Then build another...

Best,

Roy