Listening room ISSUES

Do I have that approximately right Mahgister? I want to contextualize your suggestion so I can better understand how and when the Helmholtz solution is effective to try.

Yes your cautionary remark are right...

Helmholtz resonators will not replace passive material acoustical treatment...Nor replace others rules like speakers placement...But the reverse is no less true, no PASSIVE material treatment will ever replace the resonators in a small "difficult" room...


BUT i recommend these resonators because they COST NOTHING...Except time and it is fun to experiment with...

Yes it take a dedicated room... Sorry if you are in a living room....

The obstacle for me would be this: if the resonators are very specifically tuned to remove certain ranges of frequency (and this is why they’re so good!) then one would have to know which frequencies one needs to remove or dampen.

An important point about your remark:

An Helmholtz device can be created like a very specific resonators to damp some frequencies... But the resonator will in some ratio enhance some others...

BUT I build 2 types of Helmhotz devices:

One i called a resonators with very thin aperture and neck variable in lenght and diameters...They damp specific frequencies...


But i also created Helmoltz diffusers with greater aperture with fabric cloth or/ and with a thin metal or plastic mesh to DIFFUSE all other frequencies that are not damped by my device... I use big glass water bottle with a long neck around 3 feet ( it is important to use different size for each diffuser)

Then the diffusers complement the resonators...

All experiments are made with the ears listening musical specific known timbre: piano and voices after that strings and brass orchestras....

Results: no cost and great S.Q. with an upgrading effect surpassing anything i ever try in gear upgrade....

My actual Mission speakers even if they are speakers of less refinement and quality than my old Tannoy sound better because of these acoustic controls...


The cost of my advice is ZERO DOLLARS....

Then the risk of failure is also ZERO if someone take the necessary time to fine tune all the resonators and diffusers...

It is very simple to do.... Only the fear to be wrong is a problem....






«Change the volume of the air cavity, or the length or diameter of the neck, and the frequency of
resonance changes. The width of this absorption band depends on the friction of the system. A glass
bottle offers little friction to the vibrating air and would have a very narrow absorption band. Adding
a bit of gauze across the mouth of the bottle or stuffing a wisp of cotton into the neck, the amplitude of
vibration is reduced and the width of the absorption band is increased. For maximum effectiveness,
Helmholtz absorbers should be placed in areas of high modal sound pressure for the tuned frequency.....


The sound impinging on a Helmholtz resonator that is not absorbed is reradiated. As the sound is
reradiated from the resonator opening, it tends to be radiated in a hemisphere. This means that unabsorbed energy is diffused, and diffusion of sound is very desirable in a studio or listening room....»


Master handbook of acoustics by Everest, Frederick Alton Pohlmann, Ken C. P.283

@mahgister Thank you very much for your additional explanations. And yes, the cost in dollars is zero! You have successfully communicated that point! That is very important to some people, but as you know, for people with money to buy equipment, the more important cost to them is time. And, of course, aggravation. This is why a smooth and efficient process -- by hiring someone --is often worth the money to people who have the money. They save time and aggravation.

I, personally, like the idea of understanding how the physics and acoustics of my room add up to a certain listening/sensory experience. That saves money and, for me, gives pleasure. Part of the love of audio. But even I do not want to search for a needle in a haystack, so to speak. This is why I need to see where this experimental process can become chaos rather than organized fun.

In the beginning without a good passive minimal treatment, it could seems chaos...

But after a minimal passive treatment to erase too much echo in the room, all is linked to your ability to listen and tune, and with feed back from listening tuning again...

It is a process when you go from chaos to order....This is listening fun experiment aiming always toward the better because what you hear said so....

If someone want to pay many thousand dollars for perhaps a way less effective solution it is not the way to go...I prefer fun listening at no cost and controlling my room myself...


Then listening the music you already love and tweaking the diameter or the lenght of a straw and listening the result, positive or negative, is not "chaos"...

Chaos is an uncontrolled room....

Any improvement go beyond "chaos"....

Our ears dont lie, in spite of those who will say the opposite...



By the way read about what acoustic companies want to sell and you will nowhere be able to buy an efficient grid of Helmholtz resonators of various size and diffusers.... WHY?

Because this grid must be fine tuned for a specific speakers in a specific room.... Then add to the cost to create them materially the time to fine tune them and we are,way, way beyond 10,000 bucks....For sure they will not use cardboord roll and discarbed plumber pipes with straws nor empty big water glass bottle....This is not esthetical....But an Helmhotz resonator work with any materials, it is the RATIO between component that count , the fact that you can use an empty toilet paper roll dont impede the sound.... 😁


I remind you that at the end my 500 bucks system is not the best there is in absolute sense but for the S.Q./price ratio i dont doubt that it is one of the best there is...Then instead of boasting about branded name solutions i prefer to suggest creativity at no cost because it work....

For sure any people able to afford very costly system will never do this work not even believe that this  acoustical control are way more important than ANY upgrade....i wrote for people like me unable to afford costly solutions or system or frustrated people with costly system ignoring basic science fact....




Your sentence illustrate my main point:

I, personally, like the idea of understanding how the physics and acoustics of my room add up to a certain listening/sensory experience.