Just...posting my experience for all to see; maybe helps (you) - or someone - avoid making the same mistake. It's sure tempting to revisit the idea with the bits GM posited.
Pretty sure its flare factor [T or S] is exponential, so would have to measure its throat [St], effective mouth [Sm] since at some point it usually becomes conical, effective axial length to find its effective flare frequency [Hz].
curvilinear horn profile mathematics - Google Search
All in all, a good question for Bjørn Kolbrek or similar.
GM
It really is, I've got two NIB Altec 421-8H M.I. drivers w/3" VC, though with only a 1/3 mm or so of Xmax, but ~98 dB/m in a big box..........unfortunately there's no efficient 3" wide range tweeters without a huge horn.
GM
It really is, I've got two NIB Altec 421-8H M.I. drivers w/3" VC, though with only a 1/3 mm or so of Xmax, but ~98 dB/m in a big box..........unfortunately there's no efficient 3" wide range tweeters without a huge horn.
GM
The Isophon HM10/18 would easily match that sensitivity. They also did a slightly smaller supertweeter.
Shoog
Well, of those i heared:
Philips 9710M is very good in the oldskool sound. Not so much extention high or low, but it does sound extremely good. I got some that i still need to put to use (planning an OB with it). For a modern response they need a woofer and tweeter altough.
TB W8-1808 is rather good in the right enclosure, but the colouration may not be for everyone. A much cheaper but almost as good sounding, but less efficient driver is the W8-2145. The W8-1772 that some here like does not do it at all for me.
Visaton B200 is one of the better OB full range drivers that I heared, but it needs a helper woofer and is not really fit for something else than OB.
But in general, i like smaller drivers 4"-6" seems to be the sweetspot for me. They can do the highs right and still give some bass (and some more than some bass). Some bigger also can work, but it need wizzer cones wich not many can do right. The Fane 12-250TC is good at it and a steal for the price they go. Smaller always need a helper woofer but with it it can be great.
Philips 9710M is very good in the oldskool sound. Not so much extention high or low, but it does sound extremely good. I got some that i still need to put to use (planning an OB with it). For a modern response they need a woofer and tweeter altough.
TB W8-1808 is rather good in the right enclosure, but the colouration may not be for everyone. A much cheaper but almost as good sounding, but less efficient driver is the W8-2145. The W8-1772 that some here like does not do it at all for me.
Visaton B200 is one of the better OB full range drivers that I heared, but it needs a helper woofer and is not really fit for something else than OB.
But in general, i like smaller drivers 4"-6" seems to be the sweetspot for me. They can do the highs right and still give some bass (and some more than some bass). Some bigger also can work, but it need wizzer cones wich not many can do right. The Fane 12-250TC is good at it and a steal for the price they go. Smaller always need a helper woofer but with it it can be great.
Well, the only other way to make the sound good is using an extreme big sealed one, like 1000L, wich is the size of an wardrobe or an American fridge. Then you have an F6 of 30hz and a flat response. But the waf factor of that is very small i think...