speaker needs envelope detector for AM?

[electronics_kumar]

in envelope detector, we are eliminating negative cycle
one of the reason i found in a book is like this.....the average cycle of AC wave is zero..if we feeding the speaker with alternating quantity ,speaker's diaphragam will not respond..so that we are eliminate negative cycle by using halfwave rectifier(diode/envelope detector) first and filtering RF by means of a capacitor..then finally journey towards speaker.....My question speaker will respond only to non AC quantity.....i'm confused whether it is right are wrong

 

[klystron]

The speaker has a low pass frequency response. The speaker will not defelct for AC signals with frequency more than say 20 kHz.
The envelope detector will demodulate the AM signal on the RF carrier

 

[Borber]

If the quoted statement is true you would not be able to hear any soud from speaker. And it is not the average value of the signal that produces sound but it's rms value.

 

[jeffttan]

if we feeding the speaker with alternating quantity ,speaker's diaphragam will not respond..

a speaker requires an alternating quantity to produce sound. if you feed the speaker with a dc signal, you won't hear anything or just some noise.

the tone produced by a speaker is dependent on the frequency. the loudness is dependent on the amplitude.

Added after 1 minutes:

the envelope detector is used to get the envelope of the AM signal. (i.e. the information signal is the same as the envelope of the AM signal)