Yes. If you attach anything to the line out then that gets all the audio output. It’s a shame they didn’t allow you to switch between internal speaker and line out via a voice command. That would have been handy.
or, better still, to have the spoken responses via the internal speaker and the music via external. My dot is in the living room, so we can still ask it to turn down the lights in there, or add something to the shopping list or whatever, but it’s a bit ‘hit and hope’ if the amps not on.
I’ve just bought another echo for the bedroom (already got one in the kitchen) and a logitech harmony elite (also half price today) to allow the dot in the living room to do full automation in there of all the tv kit. After 2 years my wife still doesn’t know how to turn it on properly, so it seems like a good choice :). I find the audio quality fine for idle listening, but obviously not up to scratch of a ‘decent’ system elsewhere