The sound was a little dead, so I added perforated MDF at ear-level to help restore some high frequencies. If I'm honest, it could probably use more. Finished interior Finished door. The headphone amp I mainly added because I was no longer sitting directly in front of my audio interface and this helps to span the gap. Since StudioOne allows for remote control by app (via WiFi), the plan is to control session via an Amazon Fire tablet that can double as a lyric sheet. I'm a little disappointed by the sound isolation achieve (definitely muffled, but by no means absolute), but maybe I just had unrealistic expectations. If I had to do it again, I would probably use more seals. The next time I take it apart I will probably add a layer of isolation on top of the walls to help with the ceiling, and use seals on all joints. I finally got around to testing it by placing a mic outside the booth and playing the same (strummy) groove on acoustic guitar with the ...