A few years in the making, with the room treatments and speaker positioning providing the final edge to bring that sweet “in the room” imaging and sound-stage that analog+tubes can deliver.  The room being so small has meant that small tweaks make big differences.

The acoustic panels on both side walls, the quadratic diffuser on the rear wall, the record storage/display and subwoofer are all DIY.

The frequency response plots show the "before" and "after" the speaker positioning and room treatment additions.  Many a Saturday with my best friend, the "Room Equalization Wizard", a testing mic and lots of patience.  I'm not sure I'll ever get rid of that 35hz bump caused by a room mode.