Hey... nice rear view of that room! From the other frontal photos I've seen, it looked more like just a large collection of various audio gear than a listening/home theater room. I wasn't sure if you actually used it for HT.
I love the classical LP's and box sets back there! Although the photo is a bit fuzzy, I can make out what some of the labels are. I've got good practice at that squinting at various fuzzy photos of record collections for upcoming estate sales.
One question... why so many reel to reels?
I have just remembered I forget to reply to your post, please forgive me.
There are a number of reasons for the Reel to Reel recorders.
The Revox A 700 I have had since new, ans also the bespoke Brenell machine. The latter uses the Mk 6 deck with the parabolic head path, and is a very rare machine indeed. Also it has four heads. It can record two track stereo, but can play back two and four track stereo. It also has dbx code/encode available. The A 700 has professional dbx 1 encode/decode available. Almost all my professional masters are 15 ips two track dbx encoded. All of my professional reel to reel recordings I made with this Revox A 700 and the Brenell Mk6
The other machines I restored for the love of the art. However it makes the studio versatile. The Revox A 77 Mk IV is standard speed and is connected to an Advent Dolby B decode/encoder. This latter also a restoration.
The rack mounted A 700 Mk1 high speed two track has Dolby A available.
There is one A 77 Mk II two track high speed that I was going to use as a parts machine, as it was in rough shape. However since it had the nice burnished steel deck I decided to restore it. I carefully re burnished the fascia, and got all the scratches out.
The only one of the A77s that was in decent shape was the A77 standard speed four track. However it had serious internal problems, including a dead square wave generator for the capstan motor.
So the studio is a high end music and AV room, with a museum attached if you like.
Visitors are almost always fascinated by the vintage gear, and astonished at how it gives little quarter to the latest digital wizardry. In fact the high speed machines with dbx 1 no quarter in two channel.