Windows in a listening room

I skimmed the video. He seemed more interested in absorption than reflection- the latter, I think is the real issue.
I would definitely add something to diffuse the reflected sound from the glass.
Having a room with bookshelves, curtains, blinds and furniture does a lot to breaking up sound waves.
B

Lots of curtains absorb sound. You can actually hear it in the store. Put your ear right up to the curtains/carpet or wall covering. Lots cheaper than $600. :)

Best,
E

You should have my music room!
Seriously, take it!

I have 4 walls of glass.......
It is basically the sun room add on to the house. So 8ft glass sliding doors open out to it, then each wall is 3ft solid lower then 5 ft window all the way round.
Oh and it is tiled floor.....

So wood blinds on every window set just past halfway closed. 3 big squishy leather sofas and cushions. Huge deep thick floor rug. 

Made it very liveable and I am constantly impressed with how good it sounds considering how diabolical it should/could be.

It's hard to say without listening.  I can say the very best room I was ever in was a small room but was very, very dead acoustically.  Overall, I would lean to highly damped rooms than live ones.