Resonance Circuits and Resonance Systems

[Low-Q]

The problem with the 100% acoustical efficiency is if you have an identical speaker/subwoofer, as a microphone, 1 meter apart from the active speaker, it cannot pick up the same energy as you put into the active speaker.
The air between have too much loss to activate the "receiver speaker" in a way that it can deliver 1W from its moving voicecoil.


The efficiency is measured at 1 meter. What happens if you move the mic 0.5 meter closer? Is the efficiency 400% because it sounds 6dB louder there? No, you can't. Even if you glue the membranes together on both active and passive speaker, you cannot get more energy out of the other voicecoil as you put in to the active one.


That's why you cannot compare acoustical efficiency the same way as you do with a motor.


Vidar

[Magluvin]

The problem with the 100% acoustical efficiency is if you have an identical speaker/subwoofer, as a microphone, 1 meter apart from the active speaker, it cannot pick up the same energy as you put into the active speaker.
The air between have too much loss to activate the "receiver speaker" in a way that it can deliver 1W from its moving voicecoil.


The efficiency is measured at 1 meter. What happens if you move the mic 0.5 meter closer? Is the efficiency 400% because it sounds 6dB louder there? No, you can't. Even if you glue the membranes together on both active and passive speaker, you cannot get more energy out of the other voicecoil as you put in to the active one.


That's why you cannot compare acoustical efficiency the same way as you do with a motor.


Vidar

I keep hearing you say it...

If the speaker is 105db@1w 1 meter it is considered 20%efficiency. 

Now if we measured it a .5 meter it would read 6db more, 111db, but still an eff of 20%. 

.25 meter would read 6db more for 117db, but the eff is still the same.

The distance is relative to the reading not eff. It just so happens that they measure it at 1 meter, of which if the speaker were 112db @1w at 1 meter, the Pin would equal Pae, which would be 100%eff Pin = Pout.  Now if we have 8 of the pioneer 12s @105db sense, total of 1 w in, we would be at 114db @1w at 1 meter. 158%eff Pin vs Pout(Pae). Now we go 16 12s. Puts us at 117db @1w at 1 meter and gives us 316.22%eff.. 

I dont see why you dont see it.  It took me weeks to get them to understand that resistance is not the cause of the 50% loss connecting a full charge cap to an empty then calculate the total energy. Maybe it will take a while to hammer it in here also.....

Mags

[Magluvin]

Also Im not talking about transferring power from one speaker to another to try for OU. Never said so. But if I did I would go isoloaded first. Speakers face to face mounted with very little air space between to squeeze. Just enough of a spacer so the rubber surrounds dont have a chance to rub. Then to do a better yet, make a ring that would physically bind the cones together eliminating air compression all together then put it in a vacuum. lol. next step would be to take advantage of resonance in the system. What ever the resonant freq of the 2 bound speakers rings at(about an octave down from 1 speaker alone, then redo the test. Then get some box resonance in the mix.

The idea of isoloading, clamshelling speakers, is the combo will work in half the volume box as well as 1 speaker in 2 times the vol. With the exception of needing twice the power, but the box is smaller if need be.  And there is a certain quality that an isoloaded enclosure has that seems to out do a single sub in the larger box.

In the tests above, I would go first no box at all. just the speakers.  But Im not and havnt suggested doing so, you did. Im just pointing out the gains and how can we get that with circuits and or motors.  You repeatedly say we cant. Thats not going to stop me. Nope.

Mags

[Belfior]

hmm please educate me.

I got a slayer exciter pushing 5V into my primary and secondary shows 200V. This is nice because the secondary feeds back to the circuit and I can play around it and it still keeps resonance.

Now my third coil gets about 5V in at the moment and that I feed into a FBR -> cap -> LED -> back to FBR. Cap shows 3.6V and this should light up my 3V LED just fine. LED has just a slight dim light on it.
LED gets a bit brighter if touch the cap's metal case.

What is the circuit missing? Does my body add more capacitance to the circuit or am I the "ground" in this?

[citfta]

Hi Mags,

I can verify some of your idea with a device I built.  Out of curiosity I built an air cored motor/generator.  I knew the output would probably be low because of not having any cores.  I just wanted to see how far I could push it and what I would get.  I originally built it with only two coils.  They were trifilar with two windings being the drive windings and one winding being the output winding.  With only those two coils and a rotor made of alternating polarity magnets my efficiency was only 17%.  When I added two more coils my efficiency went up to 23%.  I have not had time to work on it any more but I suspect as I add more coils the efficiency will continue to go up.

Take care,
Carroll