Hi picowall,
Yes noted but don't think a power resistor serve the same function. What Im curious is why the introduction of the inductor increases the sound level & also makes it clearer.
Assuming that the tweeter is a 8 ohm unit, this would mean that the henrie value of the coil is pretty high to begin with. I would imagine that the wires for each terminal is wound in opposite direction to each other, perhaps the cancellation of emf etc when signal is applied is what provides the louder & cleaner sound. Just my speculation.
Many thanks
Yes noted but don't think a power resistor serve the same function. What Im curious is why the introduction of the inductor increases the sound level & also makes it clearer.
Assuming that the tweeter is a 8 ohm unit, this would mean that the henrie value of the coil is pretty high to begin with. I would imagine that the wires for each terminal is wound in opposite direction to each other, perhaps the cancellation of emf etc when signal is applied is what provides the louder & cleaner sound. Just my speculation.
Many thanks
Wait...at the beginning of the video there is something labeled as "tweeter" but I haven't seen such a thing. A coil stuffed behind the "tweeter", never seen it.
That's completely nuts! Now you take your cheap speaker and put that coil, well, you make the connections, put the music in behind and see that it moves...clever.
Sumotan, stop watching videos
That's completely nuts! Now you take your cheap speaker and put that coil, well, you make the connections, put the music in behind and see that it moves...clever.
Sumotan, stop watching videos
Wait...at the beginning of the video there is something labeled as "tweeter" but I haven't seen such a thing. A coil stuffed behind the "tweeter", never seen it.
That's completely nuts! Now you take your cheap speaker and put that coil, well, you make the connections, put the music in behind and see that it moves...clever.
Sumotan, stop watching videos
The coil is just the tweeter voice coil that drives the tweeter cone.
All they did was pinch that coil to make a filter for the other speaker.
However, just putting a coil there would have minimal effect as there is no capacitor or resistor in front to potentially divide the signal.
Seems to me (and LT Spice) that a series inductor on its own works as a simple high frequency attenuator:
Attachments
But the inductor in the video was put in parallel with the speaker not in series.
I didn't quite get what he was doing in the video. It is a 4 lead inductor and to be honest I can't really imagine the signal flow with it hooked up that way. Is it really connected in parallel, or is it two separate windings connected in series (meaning one winding in series with + and one winding in series with -) ?
I do agree that a simple inductor run in parallel would do nothing.
Yes maybe, it's hard to see.
It could be a common-mode choke, a split series differential or a single coil across the speaker. One drops the highs, one drops the lows (in an unsafe and unpredictable way), and one does nothing.
This is not a simple inductor, it is step-up autotransformer ("booster") salvaged from a cheap piezo tweeter. It delivers more voltage to the speaker, but introduces serial resistivity - thus increasing Qts. Step-up transformer wire is extremely thin, not allowing much of power through it.
Bottom line: crap gimmick.
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Motorola didn't use this trick, but some loudspeaker manufacturers did incorporate externally their own step-up autotransformer in the "crossover". Today, there are plenty no-name Chinese manufacturers of this kind of "boosted" piezo tweeters. It works OK for tweeters, but usually the piezo disc is unsupported, or it is glued on the wrong places/points - making horrible tweeter. Many models are advertised as a "dome" tweeter, which is deceiving - the dome is glued to a piezo disc, with step-up autotransformer behind it. This one (from Walmart) is typical:
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