HiFi room acoustic treatment

Thanx,
my native language is Croatian (Croatia is European Union country, east of Italy, on the Adriatic sea). Google translator can help, but this translation often leads to confusion, especially in more complex sentences.
I plan to cover the whole wall with wooden panels with wooden slats covering 50% of the surface. Below this I would install a 5 cm thick stone wool. If I did not want to see the stone wool between the wooden slats, I would put a thin microfiber fabric. I hope the fabric will not prevent the absorption of high tones?
Throw what I wrote, under that layer of stone wool I would put across the wall of the bass trap. Gypsum board panels with perforations 8%, and 15 cm below that of stone wool. The wall is made of clay brick 30 cm wide.
I hope it is clearer now.
btw.  Can I buy an online edition of the Master Handbook of Acoustics? In that case I could use an online translator.

well, not sure if anyone here is fluent in Croatian, or if you can buy that book - why not start checking libraries to see if it has been translated, or if something similar is published in Croatian

here are some helpful sites:

only for a rectangular room:
http://amroc.andymel.eu/

http://www.soundonsound.com/techniques/studio-sos-guide-monitoring-acoustic-treatment
https://www.acousticfields.com/ode-to-the-dedicated-listening-room/

and here is one from Canada (which features the treatments they use in their igloos and snow caves):
http://www.enjoythemusic.com/canada_hifi/08_2013/improving_room_acoustics.htm

Thanx Randy!

The acoustic treatment panel has been designed and tested in acoustics laboratory, so the sound absorption curves for each panel thickness are very predictable. The result is a series of products that can improve the acoustic performance of any public space. Visit here for details: https://www.fabricacousticpanels.com/acoustic-treatment/
By using a thicker fabric panel or by incorporating air gaps between the panel and the ceiling, up to 100% of the noise can be absorbed at a particular frequency.  

I treated the walls of my shoppe in Florida, behind the listening position, with a treatment similar to what you're describing.   Don't know what color you're looking for, but: I found that simple burlap, over 2" of rock wool, stapled to the strips of wood, eliminated all the slap echo in the room.    Various(but limited) colors are available:  http://www.joann.com/burlap-fabric/prd23682.html