I am an absolue beginner in the electronics world. Though I understand the underlying mathematics and circuits. I have never used them in my professional life.
I wanted to buy a speaker compatible with arduino. Jeremy Blum website suggested an 8 ohm speaker. I looked up 8 ohm speakers and I found .25 watt .5W and 2 W speakers.
Can somone please suggest which ones to buy any other information or tutorial on speakers and arduino would very useful!
Arduino does not have an audio amplifiier that supports a speaker. There is only digital or PWM outputs. Using a speaker will only get you low volumes of sound that is rather poor quality. There are sketches that play music using a series capacitive coupled speaker but it lacks depth. For any decent sound you need to add an audio amplifier, either off the shelf or DIY (LM386).
Without it you can only drive a 1" or 2" low wattage speaker which doesn't sound ver good. If you don't care about sound quality then have at it.
You might do better by always starting your forum posts with :
1-your project objective
2- Equipment available
5- time constraints
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
As has been suggested a LM386 or similar amplifier will help.
If you are a beginner then a simple kit may be the answer.
googling simple audio amp kits
also look in ebay