Listening my Altec 21S, even for movies, I do detect that it has some kind of lower MF problem, somewhere within 500-2000Hz. Here is the dilemma, what to do with it in 2–way speaker? Pretty much nothing… Since I use the original Altec 19 crossover my crossover has MF adjustment but Altec adjustment is within next octave and sonically as I move Altec own EQ then it very horribly reflects sound. I prefer to keep the MF Altec 19 adjustment at zero.
Here is two options that I can see if I willing to deal with it: 1) to drop the MF crossover point from the Altec’s 1250Hz to let say 500Hz, thankfully the 180Hz multi-sell would allow to do so 2) introduction another channel between tweeter and woofer. Both of the ways would do and I “might” try it.
What I wonder if another channels goes what driver it might be. It is not that I am in search mode for driver. I would like to spend no efforts on it and at this point my interest is purely theoretical. For sure my JBL 2490 would be a great candidate for it:
I have a pair of them, new sitting in the boxes. The problem is that when I got them I was thinking to use them with my 18-sell 180Hz horn. Now the multi-sell is busy with Vitavox S2 and I have no plans to change MF. So, to engage the JBL 2490 it would need another lower MF horn with 3” entry. I do not have such a horn. If somebody knows any ready to go 3”-entry horn of any profile with 150Hz-180Hz exit then I might try it. I would not custom design and order such a horn as I would like to have the Altec 91 project to go easy and cheap.
To drop the MF crossover point would not be a big deal and I need to try it another day…. Still, the huge amount of empty space above multi-sell with Vitavox S2 drives me nuts… and called to be filled…
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche