Talk but not walk?

glupson, as a matter of fact Michael and I both talk the talk AND walk the walk. He and I have both been exploring room acoustics for a very long time, independently. He and I have spent extraordinary effort and time finding out how things work. I was one of Michael’s first customers around thirty years ago and have measured the effectiveness of his Echo Tunes and Corner Tunes. Of course many others also were getting their hands dirty and developing products.

I designed and developed quite a number of room acoustics devices that address a wide range of room acoustics problems. My very first product was going to be Ortho Ears for improving dynamic range, modeled after Mr. Spock’s ears, but that product was overcome by events, perhaps fortuitously. Off the top of my head I have at least SEVEN room acoustics products, including some quantum mechanical ones. I developed the first comprehensive crystal-based product line for resonance control and room acoustics control. I have also spent much time and effort studying room acoustics dynamics, including mapping out the sound pressures of the entire 3D space of the room. I have built my own Helmholtz resonators of various sizes, including a 15 foot long folded horn resonator for very low frequencies. I have my own ceramic version of the tiny little 1” bowl acoustic resonators. My hands have not been soaking in Ivory liquid, Junior.

Getting back to the whole laminar flow issue for a second, we know that air moves in the room while music is playing. We also know that acoustic waves themselves travel through air at the speed of sound. These high speed acoustic waves striking a surface would be like waves of water striking the beach, no? So the dynamics of the acoustic wave + air hitting a surface would obviously have a much greater impact than one might imagine. That’s why I measure sound pressure peaks in some locations around the room that are 10 times higher than the average sound pressure in the room. That’s a lot of energy, no?

I do believe the whole subject of room issues is very real and goes way beyond what  alot of people work at with bass traps and wall diffusers etc.
After all you only need look at some websites to see what some are selling just as off the shelf items,
And I do believe certain people spending years in the research and counterpoint of these effects has been productive.
I wonder though with the wave of the latest electronic correction devices if this has somewhat negated all of this effort?

I wonder just what effect a unit like the Lyngdorf 2170 or Anthem would have on the rooms that already been heavily massaged and tweaked?
Would they be able to improve still further?
Or would they possibly make matters worse?
Be interesting to note the amount of room correction they attempt to make.

Personally I have known my room was acoustically terrible for years but then came along the 2170 and as far as I am concerned it did the "walk" for me and in all honesty I am just about done and really just sit down and enjoy the music for hours on end.
Maybe ignorant bliss and contentment but its my room...lol.

The sound gets refracted ("back" removed) towards the listener due to the change in the transmission medium i.e. hot and cold air

>>>>>I want to get on board your explanation. I really do. Can you be a little more specific and go into detail just a bit? So far I’m thinking hmmmm, maybe partial credit.

 It’s based on the same principle as why can we hear sound for longer distances in winter than in summer. You have already given the theory as to the why and how in the post above.

Since there is no air flow in a listening room you can’t create turbulent flow. You don’t even have laminar flow in a listening room.

Reynolds numbers?

Good grief.

We have such a conflation of different applied sciences here - none of which applies to audio! We are venturing into aerospace engineering and motor vehicle drag perhaps but this is nonsense in audio.

Waves on a beach? Good grief - waves in the sea are NOT elastic acoustic waves at all. Again conflating completely different phenomenon. Surface waves at an interface have orbital progressive properties. The interface is key - just like the major damage from earthquakes comes from “ground roll” at the interface.

The reason acoustic energy varies in a room is due to the reinforcement and interference of a multitude of reflected acoustic waves along with the primary. Since the reflection surfaces are rigid compared to air there is also a build up of pressure very close to the wall. Listeners should keep at least 3 feet from a wall - 6 feet is better.

A little knowledge is a dangerous thing.

Fellows you should study up on shear waves and their various velocities and polarities thru and on all solid materials in your listening room including solids in motion. Compressive becomes shear...on impact..or on solids in motion.Tom