Oh my bad, You are right auduguru, I looked at the datasheets of LM3886 and LM3875 and you are right.
But another question with regard to this point is, if the gain is just 1 at 8MHz for these Audio power amplifiers then they should work just fine at frequencies beyond 20kHz? For instance the gain for LM3886 and LM3875 at 100kHz is 80. So do they work just fine and linear at Bandwidth of 100kHz bu the gain 80 or less? Or there is another factor to be considered?
I mean If in need an power amplifier at higher frequencies (for instance at 100kHz with the gain of 80 or at 1MHz with the gain of 8) in future then those chips are an option to be considered?