Heavy metal is a difficult genre to get speakers for. You need speakers that can slam like a mtfr, have significant sound power levels in the upper bass, lower mids, mids, no phase shift between the bass drivers to midrange driver...and so on.
For example, a Schweikert 55 works good for heavy metal, dense orchestra with electronic elements, etc, in larger rooms. It can be a wallet abuser without good deal on used, too big for your room..
As you come lower in price, the Borresen X3 at 11k/pair would work good for your genre. It may/may not work/could be pushing it on room size depending on how many other things you have in the room.
As you go lower in price for your small room...well...just bring the speakers real close in nearfield, about 4ft from you and get a pair of Yamaha HS8 powered monitors with the 8 inch bass driver (only 800 dollars/pair, very affordable!). Add a KEF KC62 microsub, 1500 dollars.
(P.S. The motherload of metal albums/music you listen to got done on Yamaha monitors over the ages. The HS8 is the newer "special" version after their hifi speaker guys and proaudio guys started talking to each other a bit. You should be in good hands.)