Acoustic Panel Room Treatments : Built-in vs surface mount question

I'll try and find the Book as a search for a British Author of this type of book is not helping me identify the book.

Any invasive work into a structure has a substantial cost, where the benefit is only the aesthetic of the room, especially if one loathes the notion of a built-for-the-purpose acoustic control measure being a prominent visual item on a wall.

Firstly, about the Branded Companies, they build to a budget to achieve a certain control measure using a selection of dimensioned panels so as not to be too overbearing a visual in a typical home space used for audio/cinema. 

Putting the Branded Items aesthetic to one side, there is a budget constraint, and the materials critical to function as the control measure are not market-leading/cutting edge. There are control measure materials that are not of a dimension that makes them prominent; hence, low-profile panels are able to be produced. The same materials could be produced as a triptych to keep panel dimensions smaller, and when produced, covered with an artwork canvas that aesthetically appeals.

Diffusers today are able to look very artistic and be designed with the math that makes them a correctly functioning panel. 

Both of the above options can be produced as a DIY task, but acoustic diffusion will be time-consuming if a complex design is selected.

So far, no one is being paid to disrupt the calmness in the home, and the works paid for really don't add much, if anything.

If money must be spent, having a person competent with REW Software and room measuring equipment will be a sensible outlay to create an understanding of where treatment will be beneficial. Treatment type and the required dimensions will also be approximated. 

REW will give a much more accurate picture than blindly deciding what is needed and then selecting a self-designed dimension to be produced.

I have visited two homes having been investigated by individuals adept with REW, and the control measures in place are not really noticeable. One home most familiar to me has a small quantity of panels, being one only on opposite walls and a change of pile to a rug. 

The link shows product that can be purchased at 3/4" thick.

https://www.owenscorning.com/en-us/insulation/products/700-series-fiberglas-insulation

As for diffusion, there are many designs

https://www.etsy.com/uk/search?q=Acoustic%20Diffusion%20&ref=search_bar

. 

Vicoustica makes some large panels that are practically seamless called the VMT panels. various finishes when installed can cover a whole wall with little seams visible. The audio shope that i seen them had them velcroed to the wall and looked very good, they used the concrete look and the whole wall looked like it was a concrete wall seamless. they are about 2" thick. variouls finishes. 

VMT – Vicoustic 

Thanks @glennewdick 

@pindac that is a lot to write. Please do post once you find that book.  
 

( And yes we have REW software and a decent mic.)

You can’t paint over fiberglass and achieve the same results as an acoustically transparent cloth over fiberglass. 

This however seems very interesting to me: 

https://www.armstrongceilings.com/commercial/en/articles/acoustic-drywall.html

However, at this level of complexity I strongly suggest you reach out to a professional architectural consultant.  

@erik_squires thanks very much.  The paint over issue was one i really hoped somebody had advice and experience with.  Very helpful.  And yes.  I would not DYI this.  Just trying to start to gather ideas about what is feasible and what is not.