Will 2 watts monoblock 45 tube amp work for 90db speakers ?

Hi my fellow audio friends ! I got a question about low power tube amp , I recently interested in a pairs of 45 tubes low power amp , they are around 2 watts and I know they work best on higher efficiency speakers like horn , I currently have a primaluna preamp feed s ss amp to my Nola boxer s2 90 dB at 8 ohm and a pairs of sub , I wonder at normal listening level will a pairs of 45 tube amp will have enough juices to drives them ? My listening room is around 15 x 17 , any input ?