Chances are this has been discussed before on forums. (But searching for it isn't that easy.)
I wonder to what extent is it possible to design a crossover (or a whole speaker actually) just based on FR data on the datasheets of the drivers, and it would be interesting to spell out the issues with this idea.
Probably the most obvious issue with this idea is that datasheets often contain only on-axis FR data.
So the best that could be done for the off-axis of the speaker is to design (guess) the crossover with some assumptions in mind about the off-axis FR of the drivers, based on the drivers' radiating area, measurements of drivers that are considered similar, etc. Although I guess that gets more difficult for waveguided tweeters, and probably next impossible for horn/CD combinations?
But suppose part of this is just to have some fun with the crossover design program, or to get something preliminary going, like quick and dirty style. Or in the first case, maybe we don't even have the drivers, just want to have some fun designing a crossover for some interesting drivers on paper, but again to what extent does this make sense?
Another issue is that the FR on datasheet has been measured on a test baffle. Certainly this test baffle won't have the same dimensions as our speaker's front baffle. But if the dimensions of the test baffle are known we could create a simulated baffle response for such a baffle and subtract it from the digitized datasheet FR and sum that with our speaker's simulated baffle response. This could be done in VituixCAD. Also splicing it with a simulated box low-end response. I guess this could work for woofers, maybe?
For waveguided tweeters it seems more complicated as we don't have simple radiating area value to work with to create our virtual baffle response. Or is there a rule of thumb that would provide an approx. equivalent radiating area in some cases? I guess similarly in case of a (big, Tannoy-style) coaxial driver, the cone is a (big) waveguide for the tweeter, at higher frequencies the off-axis FR will be all inherent in the design of the driver, but below a certain frequency (depending on cone/waveguide size) what would be the equivalent radiation area if one wanted to create a simulated baffle response?
I wonder to what extent is it possible to design a crossover (or a whole speaker actually) just based on FR data on the datasheets of the drivers, and it would be interesting to spell out the issues with this idea.
Probably the most obvious issue with this idea is that datasheets often contain only on-axis FR data.
So the best that could be done for the off-axis of the speaker is to design (guess) the crossover with some assumptions in mind about the off-axis FR of the drivers, based on the drivers' radiating area, measurements of drivers that are considered similar, etc. Although I guess that gets more difficult for waveguided tweeters, and probably next impossible for horn/CD combinations?
But suppose part of this is just to have some fun with the crossover design program, or to get something preliminary going, like quick and dirty style. Or in the first case, maybe we don't even have the drivers, just want to have some fun designing a crossover for some interesting drivers on paper, but again to what extent does this make sense?
Another issue is that the FR on datasheet has been measured on a test baffle. Certainly this test baffle won't have the same dimensions as our speaker's front baffle. But if the dimensions of the test baffle are known we could create a simulated baffle response for such a baffle and subtract it from the digitized datasheet FR and sum that with our speaker's simulated baffle response. This could be done in VituixCAD. Also splicing it with a simulated box low-end response. I guess this could work for woofers, maybe?
For waveguided tweeters it seems more complicated as we don't have simple radiating area value to work with to create our virtual baffle response. Or is there a rule of thumb that would provide an approx. equivalent radiating area in some cases? I guess similarly in case of a (big, Tannoy-style) coaxial driver, the cone is a (big) waveguide for the tweeter, at higher frequencies the off-axis FR will be all inherent in the design of the driver, but below a certain frequency (depending on cone/waveguide size) what would be the equivalent radiation area if one wanted to create a simulated baffle response?