Next is small planar, foster supertweeter. Great extension to 40kHz with uniform of axis. Used it a lot, as part of three speaker systems now. Its only supertweeter, i cross it very high, 10kHz.
As expected for planar, flat impedance, 8 ohm, with just tiny bumps between 2-5 kHz.
As expected for planar, flat impedance, 8 ohm, with just tiny bumps between 2-5 kHz.
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My original question about those two tiny dome tweeters remain unanswered. Why is one showing nice Fs resonance, other does not.
I did not ask why its is rising afterwards, i know that. I asked why is impedance rising in planar, since it has no standard voice coil. Its aluminium foil etched on mylar membrane. It should be flat. But the rise is tiny, and i believe hivi shows it too, so no issue.
Was about to post impedances of small bookshelfs, but there seems to be no interest in dats.
I did not ask why its is rising afterwards, i know that. I asked why is impedance rising in planar, since it has no standard voice coil. Its aluminium foil etched on mylar membrane. It should be flat. But the rise is tiny, and i believe hivi shows it too, so no issue.
Was about to post impedances of small bookshelfs, but there seems to be no interest in dats.
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Possibly the tweeter with no discernible Fs peak has a generous amount of ferrofluid damping, that can flatten an impedance peak. I've never seen one quite that flat, however. There is a tiny rise around 4K Hz.
The planar drivers still have some inductance, most every conductor does. This may be causing an impedance rise at the high end.
The planar drivers still have some inductance, most every conductor does. This may be causing an impedance rise at the high end.
Why is one showing nice Fs resonance, other does not.
sx there FerroFluid? Althou even with those you usually see a t least a tiny bump.
dave
I would not expect it in such a cheap tweeter.
I have some 60¢ tweeters with FerroFluid.
dave
Adason, I am pretty sure the planar tweeters still have inductance, larger for the larger HiVi. True ribbons have vanishingly small inductance without a transformer, but the multi-turn planar have considerably more due to the longer coil and presence of the steel grid holding the magnets. why the little dome has no peak is a mystery. Maybe the ferrofluid is partially dried out so it is extremely damped?
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