Acoustic treatments and room measurements should be done before you spend money on gear.
If you need help GIK Acoustics will remotely help with the room treatments. They did some great work on my small office.
Another option is this one. I know DSP is not always well received here but this guy can remotely make your room sound great. It helps if you are doing streaming from something like ROON or JRiver so that you can plug in the Convolution filter he would create for your specific setup.
Digital Room Calibration Services, Convolvers, Headphone Filtersets (accuratesound.ca)
Anthem also has a DSP based on their hardware. My suggestion for DSP is software based and not limited by the processing power of any audio hardware.