I saw my first Altec Lansing 'Voice of the Theatre' speakers in an auditorium at the Banff School of Music in 1973. I had already become a keen stereo buff and knew that Altec Lansing made the most popular recording studio monitors in the world at that time: the 604s, and the A7s were also regarded as top flight speakers for larger venues. I sent away to Altec to get their speaker catalog and spent a lot of time dreaming of building my own Altec Lansing monitors for myself.
This is the Altec Lansing speaker design manual that got me motivated to build a set of studio monitors (I was originally thinking of building a set of speakers that used the Altec Lansing 'Voice of the Theatre' components, and in fact the cabinets I built were sized for the same Altec 811B 18.5" wide high frequency horn and Altec 414-8A 12" low frequency driver, but in the end I found that I could not afford those components no matter how much baby sitting or paper route work that I did, and chose suitable Philips speakers which were lower cost - I flipped the lower cabinets upside-down and put the dual 2" mid-range drivers where the slot for the Altec bass driver originally had been envisioned - see below):
This is the famous Altec Lancing 'Voice of the Theatre' speaker which was the leading professionally installed speaker in theatres, rock concerts, and even some recording studios from the 1950s to the late 1970s (and which had inspired my imagination since grade 7 when I first came across a pair of them while at the Banff School of Music):
The Philips speaker catalog I ended up selecting my components from:
Some early sample drafting drawings for my 'proposed' studio monitor design from grade 9:
Here is a grainy photo of my completed 'studio monitors' built during grade 10 & 11 at the high school woodworking shop (they weighed 130lbs each, used 2x2" maple bracing internally, and were wired for tri-amplification) - notice the posters on the wall from Chicago IV, The Beatles - Let It Be, and Pink Floyd - Dark Side of the Moon: