Speakers are the most revolutionary inventions ever done in the field of communication. The modern speakers that we see today are not always like this. It took almost a century to get speakers their modern look after they were invented.
History of speakers is as old as invention of telephone. When Graham bell invented the telephone, he also invented first speaker with it, that was able to produce the sound sent from other side. Now the question which rises here is what is the basic principal on which the speakers work.
Ancient horn Speakers
This is the oldest type of speaker it was used readily in early 19th century. These speakers were not good at amplifying sound and was able to work without electricity. There was a needle which moves up and down on a rotating disk which results in production of vibration.
The needle’s another end was connected to a diaphragm which used to produce sound waves from the vibration produced. The sound produced in these speakers was of very low intensity. A horn like arrangement was used to amplify the sound produced up to a large extent.
These ancient speakers are now a collective piece and often found in museums.
Modern speakers that we see today were invented in 19th century and every speaker that we see today work on the same mechanism. However, the main principal behind production of sound is vibration and it will always be, but the efficiency to produce more realistic sound effect will be improved in future.
The speakers that we are calling modern speakers, consists of
- Permanent magnet
Permanent magnet is an ordinary magnet may be natural or manmade. It is often round in shape and hollow in the centre like a donut.
An electronic magnet is placed inside the hollow space of permanent magnet. The electromagnet is a coil bonded together which behaves like a magnet when current is passed through it. When current is passed through it. The electromagnet is essentially made up of some metal which a permanent magnet doesn’t attracts of opposes. Now when current is passed through the coil the permanent magnet starts attracting or repelling it (Depends upon the south and north pole). The amount of current passed through the coil will affect the magnitude of temporary magnet and will cause upward/downward movement of coil.
Diaphragm is a thin layer which is connected to the coil aka electromagnet, when coil moves upwards/downwards it moves along with that which results in production of vibration.
The change in frequency of current results in production of different types of sound. Human can sense a frequency ranging between 20Hz to 20000Hz.
Modern wireless Speakers
Now that we have come to know the basic principal behind working of modern speakers now let us dive into the most popular form of speakers i.e. wireless speakers, either Bluetooth or Wi-Fi.
Bluetooth speakers are a trend now a days because of its ultra-portable functionality and no need of wires to transfer the audio signals.
Wireless speakers produce the sound in the same way like other speakers but instead of using a regular power source to amplify the sound, it uses battery to supply the power, which needs to be charged. And instead of relying on the aux cable for transferring audio signals it uses wireless technologies like Bluetooth and Wi-fi.
Bluetooth speakers are a little more expensive and you can buy a Bluetooth speaker ranging between 500rs to 5000 and even more.
Every invention passes through many development stages but the basic principal usually remains same. We can expect to see some other types of speakers like a pure flat surface in future but most likely principal will remain same.