How Do These Sound Boxes Make Sound?

[padmeup]

I'm an Ipader and looking for a speaker for my phone. I found a type of USB-charged ones(http://www.tinydeal.com/apple+Mini+USB+Powered+Vibrating+Audio+Resonance+S peaker234 and http://www.tinydeal.com/apple+Mini+USB+Powered+Vibrating+Audio+Resonance+S peaker127) online yesterday. They are shaped like apples and their brand name starts with an "i" -- obviously to cater for apple. But i've found no hole on the small sound boxes, so I wonder where sound is sent out. Anyone tell me about the stuffs?

 

[letsappleit]

I've used a similar one. On the bottom of it, there is an elastic button to control the sound volume and subwoofer strength. When a heavier pressure is imposed on the button, the subwoofer become stronger. And a mild subwoofer is made when the box is put upright on a desk. In fact, the speaker itself produced very weak sound, and it generates stereo by vibrating the surface of a desk, or the panel of your car. As the source of voice is usually long or round, you may find solid voice come from every direction.

 

[Applefreak12]

i saw somewhere on the net once some suckers that go onto a window, you then connect them with a jack plug to a music source and the window becomes the speaker

 

[letsappleit]

i saw somewhere on the net once some suckers that go onto a window, you then connect them with a jack plug to a music source and the window becomes the speaker

I'm so interested in such stuffs and search about them on the Web.
I think the apple-like speaker somewhat used the planar speaker technology. A planar speaker can be in the shape of a frame and also other shapes. And the following is an illustration on how such a speaker works.

The vibration plate is actually a flat panel made from some selected materials. When a flat panel speaker is electrified, its magnetic-material-made exciter begins working to trigger off some complex wave motions on the panel, through which, sound is sent out.

According to some reports, a flat panel speaker performs better in terms of fidelity than a conventional one, which, in the shape of a cone, often produces twisted voices -- a conventional speaker compresses voices before sending it out. Besides, a wide angle or a long distance between a flat panel speaker and its user doesn’t impair his enjoyment so much, because the stuff emits HiFi sound waves to more directions (voices are spread more evenly).

If the speaker you linked adopted the flat panel technology, the button on the bottom should have served as a an exciter and the desk played the role of a vibration plate. Am I right?

There is a story about the derivation of flat panel speakers, by the way. At then end of the 1980s, researchers of the UK Ministry of Defence tried some flat composite materials to conceal military helicopter engines, in an effort to lower noises. But the noises were not impaired. Moreover, these materials make sound by vibrating, just like a loudspeaker. Then the researchers began the R&D of flat panel speakers. And established in 1996, NXT has long been devoted to the field.

 

[iVan]

The traditional speaker is made of an electromagnet connected to a flexible membrane, the paper around it. This magnet motor goes up and down transmitting its movement to the surrounding paper or plastic that amplifies that movement. The more the vibration, the more amplitude it gets, the louder the volume of sound.
This device appears to have a coil end that would make the surface it touches resonate. The thinner the surface the louder it will vibrate. Put it on a drum head surface and it will do its best.

The apparent genius of this one is that it's standing on its coil making the whole device move up and down instead of the other way around, giving more mass for such a light device to transmit vibration.

 

[padmeup]

But what kind of surface or panel best realize its function?