Acoustic treatment and acoustic mechanical control over gear upgrade for improvement

All of my room correction is mechanical. Angles on a ceiling portion and angles on a soffit.  No foam in use only real sheeps wool behind cloth covered stretcher bars and only 5 of these in this large room. I use 1 each of the threaded inverted Audiopoints coupling discs screwed into 3 of my sound panels. These brass devices are located and tensioned by ear so as to extend the stage down the side walls and  maintain focus  closer to my space. These work and sound best by tightening by hand and then just backing off a 1/4 turn.  I originally used more but it was like watching a laser show of connect the dots. This was exciting but I decided it was not real..so only 3 remain. These are all.about the conversion of shear waves to the compressive.

With my recent speaker rebuild I needed to augment the bass but the real suprise was how it augmened the vocals and further enhanced an already wall to wall soundstage. Since this finding I have built more of these simple devices an located them to enhance laminar flow in the room. Think of an increase in laminar flow as a reduction of interfering energy air molecules collide but there are ways to make them smoother.

If you have speakers and a rack and furniture then laminar flow is disturbed while listening. I forgot I have 3 Argent Room Lenses a laminar device on the floor behind my chair and an active mothership contol device 10 ft behind my chair. Pretty much my boundaries are gone.. Experiment.

Tom

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Thanks Tom for this interesting post...And for all your ideas...

This will give impulse to some to experiment ....

My best to you....

For those who doubt that my Helmholtz tuning method with a grid of tubes can tune a room here, what i call "mechanical equalization", here are some simple basic observations to read from a MASTER book i just discovered 5 minutes ago ...

I cannot reproduce images of the text here, nor the equations correctly, but the text say it all and give some basic understanding about an important fact in my grid of tubes : The more absorbing tubes and the more diffusing one, or the open/closed tubes and the open/open tubes and the case in between these 2 types, with mutiples littltes tubes inside a bigger one, and also some tube with  a cloth fabric filtering device at one end and the other end open... These are the 4 types of tubes of various size at different locations i used in my "mechanical equalizer"...

«2.5.3 Sinusoidal wave excited by a velocity source in an acoustic
tube.

In the last subsection sound waves were shown to be excited by a sound pressure
source at the entrance x = 0 of an acoustic tube. Another type of exciting source is a
velocity source.
Fig. 2.16 shows an image of an acoustic tube with an open end at x = L, and a
sinusoidal velocity source at the entrance x = 0.

The boundary condition can be formulated such that
p(x,t)|x=L = 0 (Pa) and ∂p(x,t)∂x ����
x=0
= −iωρV eiωt, (Pa/m) (2.54)
where
v = V eiωt (m/s) and − ∂p
∂x
= ρ
∂v
∂t
= iωρv (Pa/m) (2.55)
hold [1][7][13] between the sound pressure (Pa) and the particle velocity v (m/s) for
sinusoidal plane waves, and ρ (kg/m3) denotes the volume density of the medium.
Assuming the general solution given by Eq. (2.43) once more, then the solution
must satisfy
Ae−ikL + BeikL = 0 (Pa) and Ak − Bk = ωρV (Pa/m) (2.56)
under the boundary condition specified by Eq. (2.54). Solving the simultaneous equation in Eq. (2.56) for A and B, then the general solution can be rewritten as
p(x,t) = iρcV
sink(L − x)
coskL
eiωt. (Pa) (2.57)
Comparing the solution given by Eq. (2.57) with that by Eq. (2.46) for the sound
pressure source, the poles of the solution for the velocity source are located at lower
frequencies:
cosknL = cos
ωn
c
L = 0 or ωn =
c
2L
(2n − 1)π. (2.58)
The fundamental (n = 1) is lower than that for the pressure source by 1/1−octave.
The pressure response to the velocity source is purely imaginary. In addition, the
poles are composed of odd harmonics without the even harmonics. The difference in
the poles between the pressure and velocity sources can be interpreted as the difference in the boundary conditions for the acoustic tubeFig. 2.17 displays the two types of boundary conditions for acoustic tubes: openopen and open-closed end conditions [17]. The open-open tube represents the case
for the pressure source that makes the condensation or dilation of the medium at the
entrance. Assuming the impulsive condensation at the left end, then the pulse-like
positive pressure travels inside the tube. The pulse-like pressure wave is reflected at
the right end (open end) by the negative magnitude. The return of the negative pressure wave to the left end changes the sign of the pressure to positive, which goes
toward the right end. The periodic traveling yields the fundamental frequency.
In contrast, the propagation wave from a velocity source can be interpreted as
the traveling waves in an acoustic tube under the open-end boundary conditions, as
shown in the right panel of Fig. 2.17. Velocity excitation might be made by piston
motion of a “plate” at one end of the tube. As happens in the open-open tube, the reflected pressure wave with the negative sign comes back to the source end. However,2.5

Acoustic tubes with open-open and open-closed ends, where pulse-like waves propagate
between the two ends; from Figs. 4.1 and 4.5 [17].
no sign change occurs at the end because the end is closed by the piston plate, which
reflects the wave without a sign change. This traveling of the pulse-like wave is periodic; however, the period is two times longer than that for the open-open tube. The
longer period makes the fundamental lower by 1/1− octave than that for open-open
tube [17].
The two types of boundary conditions may represent the conceptual models for
a flute by the open-open condition, and a clarinet by the closed-open condition. The
difference of the boundary conditions might explain the difference in the fundamental
frequencies with their harmonics. However, the boundary condition for a clarinet
might be mixed rather than purely open-closed [5]. The harmonics can be composed
of even and odd harmonics even for a clarinet.»

Acoustic Signals and hearing by Mikio Tohyama 2020

Apart from classical passive acoustic treatment which seek to optimize the balance between absorbing and reflective surfaces and diffusive one,

Apart from the mechanical equalization of the room by modification of the pressures zone distribution and modification of the shear velocity of the waves in some location with different Helmholtz open/closed/filtered tubes which act as resonators and diffusers...

The most important addition to my room were the low cost grid of Schumann resonators modified and tuned with copper/shungite+quartz ....

But way less known and underestimated is the ionization effect on the room acoutiscal properties...

I used three type of ionizer, 2 low cost chinese ionizer for cars but that work well after a year of non stop use in my small room, a more costly one of french design which is the most powerful i put between my speakers and near listening position, and 3 himalayan salt lamp which are the less powerful device for sure but anyway work for me under my desk with a glowing orange light that create anyway  also by his beauty a placebo effect ....The effect of all these ionization is very audible and easy to verify when you shut them on or off...

But Ionization is the LAST so call "tweak" to add to a room...

It is the ice on the cake with the cherres in room installation ....

If you put it first BEFORE passive material acoustic treatment and with no mechanical control over the room the odds are you will be in the camp of those objectivist who mock any audible sound effect not measured yet because you will not hear it in a bad room... An effect which is audible but stay subtle is no less spectacular than a more evident effect like improving timbre or dynamic or bass ....The cherries distributed on a chocolate cake change the taste of the cake even a few cherries will do....

Then beware...

Acoustic embedding control has a list of priorities:

--Passive material treatment...

--Mechanical control after Helmhotz....

--Schuman generators...

--Ionization of the room....

Perhaps the title of my thread would have better been named : gear fetichism and consumerism conditioning over acoustical method and some other embeddings controls...

But the subject matter is so vast and complex anyway and acoustic and psycho-acoustic are the more underestimated matter in audio and at the same time the most important matter...

Only consumer conditioning and gear fetichism conditioned ignorance explain why the essential of hearing and listening experience is considered secondary to the gear choice and "taste"....

It is the audiophile paradox: Sound is associated with the name of a favorite brand over acoustic knowledge...

RCA victor dog entered DEEP  in our subconcious understanding... The dog listened music or his master voice  from the pavillion of a turntable or gramophone WITHOUT ANY ROOM between his ears and the gear...

Think about it....