| i_should_coco wrote:|
|I guess these would work nicely from 300Hz to ??? Can the S2 really go that low? I've heard differeing opinions....|
How low the S2 really go? It is a little bit complicated. First of all there is an objective S2 ability to go low and second there is a reasonable limit were it makes sense to use it.
Objectively it is very simple to test the S2 ability to go low. Take an S2, with clean gap and well aligned diaphragm. Take a generator and feed the S2 with valve at I would say 1.5V. Slowly move across the frequencies form 1000Hz down. At ~450Hz you begin to detect minor inflections of resonances. You will be able to deal with them by using different methods but you will win a couple dozen of Hz, no more. At 350Hz the S2 still will do sound but it will be with quite lot of buzzing in it. Surely, the crossover and the lower voltage would help in the real world not to mention that this buzzing is NOT really disgusting sounding, quite in contrary (if you made those experiments then you will know what I mean). However, here is where the reasonability limit kicks in (the new plastic suspension behaves for the buzzing perspective better at sub 500Hz level but less interesting Sonically below 500Hz)
If you use S2 at 350Hz then the horn should be no less than with 150Hz -160Hz flare, if not then you get honk. 150Hz is a big ass horn, really big. Still, you need two more, relatively large horns atop (for MF, as the 150Hz horn do not do uppers MF range well) and for bottom (as the amplitude of your S2 will die at ~350Hz-400Hz and no LF direct radiator will be able to do so high, performing good enough to be mated with the horn). So, you might have difficulties to position this assembly, unless you have really large room. However, if you do have a large room, than you need to drive your drivers (including the S2 at 350Hz) with more voltage, increasing the buzzing distortion on the S2 driver. Add to this the fact that S2 is alnico driver that has tendency to be demagnetized from excessive voltages or excessive LF. Add also to the fact that S2’s sound at 300Hz, even disregarding the buzzing, not really as good as it sound at 700Hz. The driver enters at sub 500hz in the “suffocation mode” and I really do not feel it worth to be used in there.
I think 450Hz with second order in 180hz horn is a reasonable minimum save zone (with tractrix curve, I do not know how it will equate to the Le Cleach’s profile). You might get little more from Vitavox S2 but in order to evaluate how good it might be the Sound from the bottom of S2 should be viewed in context of what the upper knee of the lower frequency channel is capable off. It is MUCH easier to get excellent Sound at 300-400Hz form a larger horn and with a driver then to squeeze the last drops of Hertzs out of the dieing S2 driver.
Romy the Cat
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"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche