Digital???? Analog????

We have gone through the analog to digital transition and I don’t think it really made too much of a difference to many of us. But, what really was all the hub-bub about? What is the difference between an analog signal and a digital signal? Without getting into too much detail, I will explain the differences, and the advantages and disadvantages of each.

Analog

An analog signal is one that does not change from the time it is created to the time it is played back. When you speak into a microphone, the microphone will take your voice and change it into a continuous electrical signal. That signal will remain that way until it reaches the speaker and is played back. The same goes for tape recording. The head of a tape player takes the information from the recorded tape, and, once again, sends it through the cable in the form of these electrical signals, which the speaker takes and turns into the audible sound of your voice playback.

Digital

A digital signal is one that is changed from the get go and then changed back at the very end. What do I mean by that? First off, most signals (especially audio) almost always start out as an analog signal. After all, most microphones are analog. The difference comes in right after the sound is made. The electrical signal created by the microphone is then “sampled” and turned into a binary code. Binary code is the basis behind all of modern day computer processing. It is simply a series of 1’s and 0’s arranged in 8 bit long segments with each bit representing either a 1 or a 0. For instance, in binary code the letter ‘A’ is represented like this…01000001. So the word ‘and’ would look like this in binary code….01000001 01101110 01100100. That my friends is what the word ‘and’ looks like to a computer. Ok, so now our recording is ‘sampled’ into our binary signal and is sent on it’s way. Once it reaches it’s destination, like your TV, it now has to be reassembled from the binary code to something that is legible to people. So that 01000001 is turned back into an ‘A’.

Advantages and Disadvantages

Now analog signals have a number of advantages. The first is that it is relatively simple to create and is also relatively inexpensive. Analog signals can also easily be changed, ie distorted etc. The disadvantages to analog is that first off, they are limited to the amount of data that can be stored in the signal. With HD TV and radio, these signals are getting larger and larger and are simply outgrowing the analog way of doing things. Analog, being a continuous signal is also susceptible to “noise” or interference. Digital signals are also prone to this but, the beauty of digital, is that it is a discrete or non-continuous signal. A good example of this is a clock. On an analog clock, the second hand is continuously moving around the clock face and never stops. On a digital clock, the second hand makes distinct starts and stops in one second intervals around the clock face. Because of this characteristic, a digital signal knows what it is, so to speak, and even if it does pick up “noise”, it can rebuild itself to its original form. Ok, so what does that mean? In a few words, it means a clearer looking picture and better sound experience on your TV. Digital signals also have the luxury of being easily compressed in order to get the same information into a smaller package, thus enabling faster speeds. One of the disadvantages to Digital Signals is that it either works or it doesn’t. There is no middle road. With an analog signal, you can receive most of the signal and still get a picture, it might be “snowy”, but you will get the degraded signal. With a digital signal, if a part is missing, you get nothing. What that equates out to, is that the distances that a digital signal can travel is shorter than what an analog signal can travel. With cable and satellite TV, that is not an issue, but if you are using an antenna with a digital converter box, it may make a difference.

In a nutshell, that is the major differences between Analog and Digital signals, however if the geek in you is showing through, like it did in me, and you need to know more, then Wikipedia does a great job of explaining it. Check it out HERE……

What are your thoughts on digital and analog signals???