What attribute of electricity holds the information, i.e. the positive and negative movement of the speaker cone? How does that signal stay intact when going through things like capacitors etc.
I really don’t understand electronics.
Thanks!
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An audio signal is an electrical representation of sound waves. When you speak into a microphone or play an instrument, the sound waves are converted into an electrical signal by a device called a transducer. This signal is then sent to an amplifier, which increases its power so that it can drive a speaker or headphones and produce sound.
The electrical signal is carried through electricity in the form of a varying voltage or current. The voltage or current changes in response to the sound waves being picked up by the microphone or instrument. These changes in voltage or current are called the audio signal.
The positive and negative movement of the speaker cone is controlled by the audio signal. When the voltage or current is positive, the speaker cone moves forward, creating a compression in the air that produces sound. When the voltage or current is negative, the speaker cone moves backward, creating a rarefaction in the air that produces sound. This movement of the speaker cone is what produces the sound that we hear.
Tl:DR speakers are an electromagnet that pulls a diaphragm that vibrates the air to make sound. By adjusting how fast you send pulses, you change the pitch. They can do this very fast.
the speaker cone is attached to a magnet next to an electromagnet. very the electricity in the electromagnet and you move the speaker cone in exactly the same way. The signal DOESNT stay intact going through a capacitor, so its very carefully NOT sent through capacitors.
The actual sound signal only goes through 4 devices. Resistors (decrease volume), amplifiers (any thing that works like a transistor) (increases volume), speaker (makes electricity into sound) or ADC (Analog Digital Converter, makes the sound into a digital file a computer can handle)
The rest of the setup might have a bunch of pieces in it (such as capacitors), but the sound doesn’t directly go through any of them
There are three ways.
1. Amplitude Modulation (AM) – you start with a carrier wave of some frequency much higher than the sound frequencies you want to transmit, typically around 1 MHz while sounds are something like 10 Hz – 10 kHz. (k = 1000, M = 1000,000). You then change the amplitude – i.e. wave height or signal strength – in time with the sound waves you want to transmit. This change in amplitude can be picked up at the other end of your circuit and transmitted to the speaker coils. This is done by using diodes to turn the AC into DC, and the DC can then be used to move the speaker cone – as the current in the speaker coils changes, the magnetic field changes and the speaker is moved around.
2. Frequency Modulation (FM) – you start with a carrier wave of some frequency, typically around 100 MHz, and change that frequency a small amount in time with the sound waves you want to transmit. To receive the signal, you can couple your receiver circuit to one which is tuned to be just off-resonance, meaning that its response will change amplitude according the the exact frequency of the incoming signal, and you’ve converted the FM into AM.
3. Digital: you encode the sound into a binary string (i.e. a set of 1s and 0s), and transmit high frequency pulses conveying 1 as high amplitude and 0 as low amplitude. You then decode this at the other end back into the sound. There’s less of a direct relationship between the transmitted information and the sound, and it can be encoded (i.e. represented) in lots of different ways – you just need the encoder and decoder to be doing the same thing, or you’ll end up with nonsense.
You can represent a signal with either voltage or with current.
Audio is AC. Capacitors don’t block AC, it just repeatedly charges and discharges the capacitor. The bigger the capacitance, the lower the frequencies that can still pass through it.
A speaker is fundamentally just a linear motor, that’s run forward and reversed to create the pressure waves.
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