What is the difference between an Amplifier and a Speaker?

What is the difference between an In Line Amplifier and Powered Amplifier on a HDTV System?

• What is the difference between an In Line Amplifier and Powered Amplifier on a HDTV system? -This one, which requires no outside AC current, or DC power, but gives you a gain of 30db - In-Line Amplifier http://cgi.ebay.com/INLINE-AMPLIFIER-TV-CABLE-SATELLITE-SIGNAL-BOOSTER-HDTV-/160533549566?pt=LH_DefaultDomain_0&hash=item25608b91fe#ht_6004wt_1141 But this one, uses AC power, and gives you a gain of 8db -Bidirectional Cable-TV Amplifier http://www.radioshack.com/product/index.jsp?productId=2103093 -Also, this one uses AC power, designed for HDTVs, and gives you a gain of 15db -High-Gain HDTV-FM Signal Amplifier http://www.radioshack.com/product/index.jsp?productId=3780245 Do I really need a FM trap for a HDTV system? Which one is better?

• Answer:

  Hi these are antenna amplifiers, they boost the signal from the antenna to the tv set. it has nothing to do with HD MI that is the signal from a player like a blue ray or a laptop computer. that is a totally different signal type. as you have not given me much to go on here i will try and explain that the television receives a signal from one of two sources one is a antenna on the roof of the house or apartment block, which looks like a toast rack, or it comes from a dish which receives satellite signals. boosting the signal from the toast rack antenna is generally what those amplifiers are for, despite what they are telling you they are not self powered. they are fed with power usually from a separate power box or it could be batteries in the amplifier box. to get the sort of power levels they are telling you about, so it is to increase the signal to give you a picture and sound, the problem is they will also amplify the noise as well as the signals. which will not improve the signal by much. As the television works at a higher frequency than the FM radio the two signals need to be separated so a device called a trap or filter is used to do this so if you want a separate signal source for a FM radio then they can both be fed down the same coaxial cable from the roof where you would have a antenna for television which is a small toast rack and a much larger one one which has fewer metal rods sticking out of it. the one with the fewer rods is the FM antenna.