Also, my impression is that Fostex is partly responsible for the popularity of single, full-range driver speakers…and they happen to make rather nice horn supertweeters to go along with them.
Wideband and woofer, fullrange and sub(woofer technology). Both mean the same thing.
Thanks Dave, I'll accept your refined definitions. For determining the range, a sub can either be a speaker supplement or a room augmentation and in this case it would be the former.
If comparing the TB against a dedicated 27mm tweeter:
94cm² / 5.99g = gives 15.7cm² per gram,
VS
(1.35cm² x PI) / 0.3g = 19cm² per gram, which seems pretty close actually.
Starting off with something like a 27mm tweeter crossed at 2kHz and 0.5mm Xmax:
16x cone area gets you to 500Hz.
5x Xmax: 500 / SQRT(5) = 224Hz.
Assuming something like 350Hz for equal power above and below, I would bump up the 12" SB a bit higher, so it covers 5 octaves: from 20Hz to 640Hz say, and the TB also gets less IMD and power that way. My concern with the SB driver would be its ambitious bass and Xmax performance, which may bring up the inductance a bit.
So it could be a balancing act of keeping the TB nice and clean, without muddying up the SB by making it go too high into the midrange. One thing you could try is a 3rd order filter, consisting of a passive 1st order air-core inductor, together with an active 2nd order filter, and/or passive notch filters to reduce any hot-spots in the woofer's 1kHz+ area.
94cm² / 5.99g = gives 15.7cm² per gram,
VS
(1.35cm² x PI) / 0.3g = 19cm² per gram, which seems pretty close actually.
Starting off with something like a 27mm tweeter crossed at 2kHz and 0.5mm Xmax:
16x cone area gets you to 500Hz.
5x Xmax: 500 / SQRT(5) = 224Hz.
Assuming something like 350Hz for equal power above and below, I would bump up the 12" SB a bit higher, so it covers 5 octaves: from 20Hz to 640Hz say, and the TB also gets less IMD and power that way. My concern with the SB driver would be its ambitious bass and Xmax performance, which may bring up the inductance a bit.
So it could be a balancing act of keeping the TB nice and clean, without muddying up the SB by making it go too high into the midrange. One thing you could try is a 3rd order filter, consisting of a passive 1st order air-core inductor, together with an active 2nd order filter, and/or passive notch filters to reduce any hot-spots in the woofer's 1kHz+ area.