Is it possible to replace the speaker in the device with another one with a resistance 2 times less?

Question

Electronics

There is a car radar detector. It has a speaker with characteristics: 16 ohms, 0.5 watts. Its replacement with a speaker with characteristics of 8 ohms and 2 W will mean that:

• the device may be damaged due to a decrease in resistance and, accordingly, an increase in current in the circuit;
  
• nothing terrible will happen, and the new speaker will be able to produce sound louder.
  

I would like to receive a detailed answer "why so, and not otherwise."
Thank you.

Answer 1

device WILL BE! damaged due to a decrease in resistance and, accordingly, an increase in current in the circuit;
with a small degree of probability, we can assume that there is some kind of protection and this crap will either not work at all, or the current will be limited and the volume will be half as much