Room Treaments - Where To Begin...

That is a serious book. Good Lord. 10 pages of table of content.

My hole booklet about acoustics was 10 pages long, WITH a table of content and one "this page is intended to be blank".

That guy had something to say.. :-)

Regards

Don't judge a book by its cover. The cover says, "Acoustics hard. Use headphones."

I used GIK. Very good people to work with. I have a 12 by 21 room. Cost about 1200.. they are 6 to 8 inches thick. I could buy more bass traps but haven’t put up on my list. I can walk around the room and the music sounds good with only a little bass peak in a corner.There are many things that come to play., sub placement and speaker placement are two items that need to be dealt with.

Recently, I put speakers and subs on springs. This helped as much as the room treatments.  It is much easier when it is a dedicated room.

Vicoustics is another option. They give a detailed analysis of your room with pictures you send them. No cost to you. Good luck ! 

GIK is good, but I finally gave up on an order that was going on three months! Be prepared to wait. Ended up buying from other sources that could fill the order. Hopefully things will get better for them. I ordered diffusion panels.  Better to treat reflection points with diffusion based on my experience.  Absorption can make your music sound lifeless.