No, it's not. At best it would be about even, and at worst it would be significantly lower.
In regard to the Purify audio PTT driver shape and the surround. Notice the shape of the high end Technics R1 loudspeaker bass driver surround and those drivers are 6.5 inch- is this a coincidence or the same designer? https://stereotest.nitschkeverlag.de/images/product/000792.jpg
In the meantime, here some data on the SB19ST
Sparrow-19ST (SB Acoustics SB13PFC25-08 with SB19ST-C000-4) – AmpsLab
A good noting. It seems the Fostex FE168EZ has a similar technology too -
Fostex FE168EZ 6.5" Full Range Sigma Series
SEAS 27TDC/ 27TFF has lower harmonic distortion, but SBA typically has better off-axis response.
SEAS 27TDC (H1149) | HiFiCompass
sure, it may look bad on the plot, but is it even audible if you cross it at 3khz to the mid driver?
the vifa ne19vts looks good other then a h3 spike at 7khz, 1% dist at 98db, will this make the driver sound crap and unusable? Vifa NE19VTS-04 | HiFiCompass
the vifa ne19vts looks good other then a h3 spike at 7khz, 1% dist at 98db, will this make the driver sound crap and unusable? Vifa NE19VTS-04 | HiFiCompass
That spike will be at 21 kHz. Not audible. Does look like a good tweeter.
The problem with crossing at 3 kHz is that you’ll have a large null off-axis at the crossover frequency due to the relatively high center-to-center spacing. With a lower crossover frequency the null gets smaller.
The measurements of the Tectonic TEBM46C20N-4B fullrange speaker have been added:
Tectonic TEBM46C20N-4B | HiFiCompass
Tectonic TEBM46C20N-4B | HiFiCompass