Evolution for one million year make us focus on specific timbre voice recognition not on flat frequency response...
Mechanical equalization of a room with our EARS is better than electronical EQ with a mic...It cost nothing...Save a dedicated room...It is more fun to tune and more powerful for improving S.Q....
It take time for sure, many weeks and many months of listening experiments to tune it....
Way more gratifying than buying a tool which will make your sweet spot not so useful because located in millimeter... I have 2 sweet spots a few inches large in my small square room so good it is impossible to chose only one...