First order crossovers, 6 db per octave, are the only one's which 'supposedly' offer the least phase shift, that is energy storage, and shift from one driver to the next.
The issue at hand is the enormous amount of work that each driver, since it rolls in and rolls out at 6 db per octave, has to operate over too wide of a frequency bandwidth,causing notable limitations in dynamics , or distortions which are unacceptably high.
When I worked for THIEL Jim Thiel would attempt to compensate (in part) by using special pole piece which allowed for linear treatment of the magnetic field over the coil in the driver throughout its proposed excursion, since that excursion was by necessity very long throw. This is like saying the sky is blue, because the ocean is too. It is a self defeating, and repeating argument, and certainly a condrum for designers who chose to use this cross over design.
Some designers, feel that first order crossovers place too many negatives in the picture for a natural and relaxed sound; not to mention that the lobing effects of the drivers at various distances (you do the math) causes frequency anomolies, such as suck outs and the inverse, causing room reflexions which look nothing like the output at the speaker. That may sound benign, but imagine, every echo and room reflexion sounding different than the signal at 8 feet, or at your listening position, this causes for a confused signal to the listener. So, some question, "what if a combination of slopes could create a sound"... that, at the listener and throughout the room, are close to identical as the actual measured output of the speaker; i.e. no lobing issues, and no tweeter having to operate like this, in this scenario. Using a 3K crossover point as many do, (too high in my opinion) but in that instance, the driver is down 6db at 1500Hz, then 12db @750Hz, 18db @375. (It's after midnight don't check the math with a calculator PLEASE) So significant midrange information is coming from a (generally 1" dome). That, IMHO is too much to ask of a driver of that size and excursion potential. Plus, again the issue of the lobing, caused by sharing of common frequencies, with the mid range, which in turn is also, asked to put out vast quantities of bass, making enormous excursions. A recipe for disaster for the wrong driver.
This first order design is one of those engineering arguments which looks great on paper, but in practice faces significant challenges, and the creation of drivers which operate in a manner not generally available to them by dent of their very design, and the known limits of drivers, given the laws of physics.
Other solutions, other than phase coherence gained through first order networks, IMHO is the answer. But time and space don't allow for all to be said here.
The issue at hand is the enormous amount of work that each driver, since it rolls in and rolls out at 6 db per octave, has to operate over too wide of a frequency bandwidth,causing notable limitations in dynamics , or distortions which are unacceptably high.
When I worked for THIEL Jim Thiel would attempt to compensate (in part) by using special pole piece which allowed for linear treatment of the magnetic field over the coil in the driver throughout its proposed excursion, since that excursion was by necessity very long throw. This is like saying the sky is blue, because the ocean is too. It is a self defeating, and repeating argument, and certainly a condrum for designers who chose to use this cross over design.
Some designers, feel that first order crossovers place too many negatives in the picture for a natural and relaxed sound; not to mention that the lobing effects of the drivers at various distances (you do the math) causes frequency anomolies, such as suck outs and the inverse, causing room reflexions which look nothing like the output at the speaker. That may sound benign, but imagine, every echo and room reflexion sounding different than the signal at 8 feet, or at your listening position, this causes for a confused signal to the listener. So, some question, "what if a combination of slopes could create a sound"... that, at the listener and throughout the room, are close to identical as the actual measured output of the speaker; i.e. no lobing issues, and no tweeter having to operate like this, in this scenario. Using a 3K crossover point as many do, (too high in my opinion) but in that instance, the driver is down 6db at 1500Hz, then 12db @750Hz, 18db @375. (It's after midnight don't check the math with a calculator PLEASE) So significant midrange information is coming from a (generally 1" dome). That, IMHO is too much to ask of a driver of that size and excursion potential. Plus, again the issue of the lobing, caused by sharing of common frequencies, with the mid range, which in turn is also, asked to put out vast quantities of bass, making enormous excursions. A recipe for disaster for the wrong driver.
This first order design is one of those engineering arguments which looks great on paper, but in practice faces significant challenges, and the creation of drivers which operate in a manner not generally available to them by dent of their very design, and the known limits of drivers, given the laws of physics.
Other solutions, other than phase coherence gained through first order networks, IMHO is the answer. But time and space don't allow for all to be said here.