Ed Wolfrum, one of Golden World's Engineers, describes it.

"The west side "garage" was a loading area for disc shipments. It entered into the west side of the building and there was a conveyer belt that loaded into the second storey where disks were stored. To the north, was a very small disk lathe room with a Neumann MONO Lathe with Auto Pitch Control, EQ and Levelling and a Studer B-67 with advance head.

Also in the garage area was a live echo chamber. It was cinder block construction with splayed, wet plaster walls. I helped Tom Nixon build that chamber when I first started working there. 

Then sitting next to the chamber was an EMT plate and a Fairchild spring. When they were loading or unloading we could not use the chambers because of the acoustic coupling to the plate and the spring as well as the live room."

Note : Arthur Ashford of The Precisions recalls the staff using the Echo Chamber for Putting (golf) contests at lunch breaks.

Also, if you look at the main building, just beyond the garage entrance, the walls give the impression that the building has been extended.