Michael Minetree has posted a video of his work building his very high quality voice booth on his Echos forum. It’s a big file (22 Meg) so even on a broadband connection it will take a while to download and play. But, I think you’ll find the wait is worth it.
Update: Or, even better, Michael has emailed the YouTube info.
Very interesting, Michael. I look forward to further updates as you get closer to completion of this massive project.