Acoustic treatment question: do you agree with Dennis Foley that $46k to $65k is required?

Bull schlockey.  He's selling treatments at unnecessarily high expense.  

If there is a need for room treatment (pretty much EVERY room)....

Get a bunch of 5-foot artificial ficus trees.  ~ $40 each from At Home (home furnishing store).  Fabulous diffusers.  Carefully spread the leaves and bend the branches so that they roughly parallel to the floor or maybe pointed up a little - like a REAL tree.  Place about 2/3 of them behind the speakers, slightly out from the wall behind the speakers and between the speakers.  Use two, one on each side, to take care of mid- and high-frequency wall bounce.  Put a few along but not against the back wall.  For less than $600, the room is full of attractive diffusers.  

And they won't drop their leaves in the autumn.  

I'm using abut 15 5-foot artificial ficus trees.in my listening room with quite excellent results.  Others have reported similar results.

For those contemplating building their own, here is the source for the activated carbon:

Carbon Activated Corporation

2250 S. Central Avenue,  Compton, CA 90220

Tel: 310-885-4555 x229 l Mobile: 1-424-379-6709

www.activatedcarbon.com

Use the pelletized carbon - 1.5 mm pellet 

I have an entire building surrounding my listening room with a couple of floors, bedrooms, bathrooms, 2 car garage...worth way more than 65 grand and it sounds great.

@ shalommorgan, Very impressive, looks smart and purposeful. Did you measure the room performance as you were adding treatment?

@ pureaudio, wow, I am appalled at the good money you spent and without the reward. I sympathise.

Re: Denis Fooley, what can I say?

@ hilde45, I did offer a gentle warning about the above gentleman. It is really not necessary to pay that much to transform your room's performance. DIY goes a long way in keeping costs down. My 2 bass traps cost me about $220  Just these 2 made a huge difference but measurement shows that I need at least 1 more.

@bpoletti. your dust collecting ficus trees unfortunately can not in any way address low frequency problems.

Fact: Lambda = velocity divided by frequency, so a 40Hz wave is 343/40 = 8.58m, over 28ft. long. At 20Hz it is double that length!

In the photo below is the start of a bass trap, built from cheap construction timber, plywood and rockwool, the closest equivalent to OC703 I could find.

https://imgur.com/Lwx8NTR          

Did a little search on "fake plants." Some really funny replies and results, but not much in the way of confirmation they can help much. https://forum.audiogon.com/discussions/fake-plants-behind-speakers-a-good-idea