Exploring Resonance And Efficiency Of Speakers And Subwoofers

[Magluvin]

Or might we experience the same loss using a 100%eff 'speaker' as a what you say, microphone just because it may be a great driver but not configured to be a great generator? I dont know yet. Ive never had a device that is 100%eff yet. Will have to be tested. And there may be ways to build a box specific for the microphone speaker that helps it become a more eff generator.  Again lots to do and lots to think about.


Mags

Now lets consider the 100% eff 112db@1w sensitivity speaker. Is it perfect? Is it as far as we can go in sensitivity? In this world I say not. Can that 112db @1w speaker be modified to be greater than 112db@1w?  Maybe.  Maybe the reason they give us this Sensitivity specification 'instead' of the actual efficiency is to hide the possible fact that speakers can possibly be made to exhibit more than 100% efficiency.    Otherwise why is it not that easy to find actual efficiency ratings of speakers and they only give us the sensitivity in db@1w specification instead?    Maybe they are hiding something right under our noses.

Mags

[Magluvin]

If we were to make a custom speaker that has a sensitivity rating of 114db@1w and put it on ebay 'and' we identify it as being 158%efficient, would we have a problem there???

I think the db@1w spec is a diversion from the efficiency truth. I think.

Mags

[SkyWatcher123]

Hi magluvin, thanks for sharing the valuable information.
Maybe i already mentioned it in another thread, though i observed this gain in a pulse motor i built.
It was an air coil motor, with permanent neo magnet rotors on both sides of the coils.
I had 8 coils i think.
Well, i measured the shaft torque with my hand and checked amperage input and kept a similar loaded rpm also.
So i progressively added coils in series, while increasing the voltage input and keeping the same watts input as the one coil.
By the time i was at 8 in series, the shaft torque at a similar loaded rpm and same watts input, it was too painful to hold the shaft very long, where as, with just the one coil, the shaft torque was feeble.
So yes, at least in the motor setup i built, it does seem to give greater shaft power gains.
peace love light
Edit: Just thought of a cheaper way to test the ganged motor idea.
What about using those motors that come with the kiddies plastic electric ride on cars.
8 of those and kids will be pulling wheelies or geared for more speed on same input in a grown ups go kart.

[Magluvin]

Hi magluvin, thanks for sharing the valuable information.
Maybe i already mentioned it in another thread, though i observed this gain in a pulse motor i built.
It was an air coil motor, with permanent neo magnet rotors on both sides of the coils.
I had 8 coils i think.
Well, i measured the shaft torque with my hand and checked amperage input and kept a similar loaded rpm also.
So i progressively added coils in series, while increasing the voltage input and keeping the same watts input as the one coil.
By the time i was at 8 in series, the shaft torque at a similar loaded rpm and same watts input, it was too painful to hold the shaft very long, where as, with just the one coil, the shaft torque was feeble.
So yes, at least in the motor setup i built, it does seem to give greater shaft power gains.
peace love light
Edit: Just thought of a cheaper way to test the ganged motor idea.
What about using those motors that come with the kiddies plastic electric ride on cars.
8 of those and kids will be pulling wheelies or geared for more speed on same input in a grown ups go kart.

Hey Sky

Thanks for the info on your findings.  There may be other things that help with efficiency gains of this sort. Like if we have a pulse motor, we tend to have the magnets on the rotor and the coils stationary. If we could do it the other way around and have the coils on the rotor and the magnets stationary, then the motor may not have a lot of its own weight/mass taking up motive power by having to use energy to get all that going.

For example the coreless motor. The armature is basically the windings encased in or on light weight plastic. No core on the armature reduces the mass weight of the armature a lot resulting in a very efficient motor.

http://www.robotpark.com/Coreless-Motors

So I see the speaker as a similar type of motor and thus very high efficiency can be had there.

So your info is at least 1 confirmation of my theory that more drivers, whether it be more speakers or more coils on a pulse motor can give us an increased efficiency. Thanks very much for revealing your positive results and helping this thread get underway. Feel free to join in anytime and show your findings as they relate to all this.

Like I said earlier, just a simple doubling from 1 to 2 drivers may not show a lot of increase. But I believe 1 to 4 would show a significant jump to substantiate my claim.

It would be very easy for someone to try 1 to 2 and not really take notice of the possible gain in efficiency and not even bother looking for more eff by making the jump from 1 to 4 and compare.  So what you have provided was very helpful indeed. And I like that you had the same way of going about it as I had suggested where as you increase the number of drivers, you adjust the input to be the same watt input in all cases for comparison. It is fool proof, rather than possibly being confused by a lot of configuration calculations and load power measurements that can get more difficult to obtain final results by not doing so. Its just simple to maintain 1 particular amount of watt input for every test. Good job. And welcome to the thread.

Here is a good example that may help with electric cars. If most are driven by 1 electric motor to drive 2 wheels, then 1 motor on each of the 2 wheels should improve efficiency. Then go to 4 motors, one on each of the 4 wheels. There should be a significant jump in efficiency compared to only 1 motor with the same input for each case. Then to possibly increase eff a step further, make the motors brushless hub motors built into the rim to eliminate any gears and or linkages that may add inefficiency.

Oh this thread is gunna be fun.

Mags

[Magluvin]

As for the ganged motors, if they have 2 output shafts, one on each end, then having the say 4 motors shaft to shaft would be more qualified for the job. Im sure there will be lots of new things we will come up with along the way to test these things.

Mags