Nokia 8.1 has a single speaker with smart amplifier.
Nokia 8.1 has a double channel LPDDR4X type of 4GB RAM.
Yes, Nokia 8.1 does have the EIS. It also has OIS also.
Yes, Nokia 8.1 does have the HDR10 support and you can watch 4K videos on Nokia 8.1. You can record 4K videos also.