Re-measured my conical horn today with speakerworkshop.... and guess what, it now reckons response only goes to 1.1/1.2KHz or so :@ It did say 1.6KHz just yesterday. I dont know whats happening there but I tried a million times and it just doesn't wanna do 1.6KHz any more. Perhaps it was a resonance or noise or some other sort of crap that isn't coming up anymore, although I did smooth and filter out quite a lot of that junk... so I still am not sure whats happening there.Perhaps its time to try a new driver. Just analyising the Alpha 6 I was using again, its Fs is 120Hz, BL is 8Tm and Qts is 0.54. I think that the Qts is rather high for use in a horn.... perhaps this is limiting its HF response.
Using driver mass rolloff equation =2*Fs/Qes gives a mass rolloff on the Alpha 6 of 393Hz.
After searching around a lot, I saw an offering by Eighteen Sound which looks like a good candidate for my horn, model 6ND410. Its a 6" driver with a BL of 11.6Tm, and low Qts of just 0.24, and Fs is 120Hz. Driver mass rolloff equation gives mass rolloff of 888Hz! Very high compared to all other drivers I have looked at such as P.Audio ones and a couple of JBLs.
Hornresp predicts that the Alpha 6 and the 6ND410 both have about the same HF response in my horn. But the Alpha 6 in reality doesn't.... perhaps, the higher BL and lower Qts of the 6ND410 will make it better for the HF response that I (apparantly, grrrr at SW!) am missing with the Alpha? Below is the spec sheet for the 6ND410.
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Of course JBL LE5 would be nice... but very rare.
Anyhow if anyone has comments on the 6ND410 etc, I would appreciate it. I would like to know weather or not its worth buying and testing out in my horn or not. I know 18-Sound does not make cheap quality stuff, however I want comments on the suitability of this driver in a horn etc, weather or not I would see an advantage over the Alpha 6...
Thanks for any advice guys!
Adrian