Helmhotz resonators for audiophile at almost no cost and without calculus...


The importance to treat the room if you have speakers, even in nearfield listening like me, is imperative ...

Here is my advice: 

Buy some big  empty wine bottles, or drink them before, it is optional....Or use some carafes, the kind that some display at the center of a table....I use plastic  wrapping sheets to tightly seal the aperture of the bottles and the carafes after pouring in them around 10 % of water in their volume space...You must listen and experiment for your taste and room to determine the exact amount of water to boost the frequencies that will benefit….After that  I peirce the plastic sheet with a needle and I insert a  thin straw with only the extremity of the straw at the top...  That its! You know have an Helhmotz resonator... 

You now have one of the more astounding tweak for a room that will transform your listening space in sound heaven ...I use more than 15 of them in my little audio room and trust me that is one of a kind upgrading...

I wrote that for those who want to experiment, the others can stay silent...My best to all...
128x128mahgister
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The exact location is dependant of the configuration of the room... I have determined all locations for mine with my open ears... It is easy and fun... Try it and dont bother with the risk of some errors...The ears are a great master and will correct you...

The results are astounding... Many company sell resonators, but I dont have money, certainly not this kind of money...But it is more fun and more satisfying to gain the same results or almost the same with cheap material.... I had this idea to make one to verify the reviewers  who described many very costly products...My result speak for itself... It is not necessary to pay...Go and enjoy...
I put the bottle and carafe on the wall behind me and on the other 3 walls  at certain spots on shelves...Some are on a table near me... The results are holographic clarity...Nothing compare with that.... The best dac or amplifier cannot make for the room... An audio system is linked to the room and the room is the first and foremost component of an audio system with speakers...
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Is it possible to post a picture, I would like to see the position of the straw.

Thanks
You can find sound pressure peaks using an empty sealed box and a test tone (for example 315 Hz). Walk around the room holding the box with test tone playing moderately loud on REPEAT. When the box starts to vibrate in your hand that’s where a sound pressure peak is located. Some places where you will probably find these sound pressure peaks are room corners on the floor and ceiling, first reflection points on wall and floor, about a foot directly above speakers, behind and in middle of speakers at rear wall, on floor in front of and in between speakers. Just placing a vase or bottle on top of speakers should be audible although it may hurt the sound if not pre-designed, I.e., just an arbitrary vase/bottle.
Thanks Geoff I had already identified some of these spots with my experiments... I will probably go on with your idea with a sound level apparatus...Luckily it seems that the dimension of a carafe or wine bottle plays positive role in my small room approx. 17 feets by 15 feets by 15 feets...The diameter of the straw,the length of the straw and the volume of the carafe or the bottles are certainly in a acceptable range relative to the room size, because the improvement is spectacular... I will sleep on the calculus...My best to all...

 I already have some bottles behind my speakers in between and behind my back on the wall facoing the speakers... Some bottles are near the ceiling ,some are on the lateral wall on shelves, some in front of windows...
No need for a photo, imagine a big wine bottle, go on with around 10% water + or -, wrap it and seal the top with plastic sheet, pierce it, insert a thin regular straw and listen, changing the spot and the level of water.... Go on with that with 2 carafe or 2 bottles at the same times in different and complementary spots...You ears will speak to you...
Perhaps I must manufacture these bottles,call them " crystals bottles" and sell them 500 hundred bucks each...
Placement cannot be the same in different rooms,then have fun and play, the final results will be inexorably an improvement for you...
My electrical grid and my audio grid are already cleaned with stones and crystals connected grid of my own design with great results... My nearfield systems is already treated against mechanical vibrations also with my sorbothane sandwiches... But these Helmhotz resonators put the system on another level... My room was already treated acoustically by me before these H.Resonators experiments...But with these H.R. the sound is clearer on all frequencies, the imaging better, and the listening positions possible in the room are way better...
By the way thanks to Geoffkait for his short articles about H.Resonators...I have begun  my experiments after reading that...My best to you...
Note - for a given volume V of the bottle the operating frequency of the resonator is completely controlled by the neck or nozzle, length and cross section area. Everything else in the Helmholtz equation is a constant.
Thanks Geoff...For this precision information...All my bottles had approximatively all the same volume except for some 2 variations linked to the species "carafe" or "bottle" with the same thin straw inserted in each one, that explain why the resulting effects are consistent and positive for my hearings... Better higher and bass frequencies, better imaging, better sound anywhere in my room... Spectacular effects... I luckily discover by chance it seems the right ratio between the volume of the bottle and the length and the cross section of the straw that act as a nozzle, for the right effects... 

By the way there is no negative impact on the sound with these carafe and bottles sealed with a straw inserted in them, except the placement  for sure in the room have an impact for the better or less … Then experimenting for the right placement is necessary... 
I participated in a recording with a nutty songwriter who wrote out the "sheet music" for every participant, each of us having a number of bottles placed in front of us. Each bottle was filled to a level such that the unfilled volume created a specific tone (note), and each bottle was numbered. The notation specified which bottle was to be blown into at what point in time, the combined "playing" of all the participants creating the music. There are easier ways to make music!
With this kind of carafe (for one liter of wine) I think the mathematical ratio with the volume/ straw is optimal...It seems that they affect sound in a way more than positive...

https://crystaljulia.com/9276-tm_thickbox_default/crystal-wine-decanter.jpg


By the way I apologize for my bad orthograph of the  Helmholtz name....If some Op can correct it I will thank him...
Ok after the carafes + thin normal straw, described in a precedent post.... I experiment also this after-noon with a big 5 gallons empy plastic jerrycan for oil with less than 10 % water in it+ a large plastic straw for slush glued to another one, inserted trough the plastic wrap paper sealing the nozzle of this jerrycan and guess what?

The bass was improved to the limit of my speakers with clarity without compromising the effect of my other generators on the other sound frequencies... Really amazing, almost no cost...This Helmholtz resonator are the second most amazing tweak of my life...

The carafes and the jerrycan act complementarily on different sound frequencies without obstructing one another to my ears...Stupendous, it is like I upgraded my speakers that now go way more lower in bass without loosing nothing but with gain on clarity on all frequencies...I apologize for my bewilderment...
I add a 2 gallons+2 thin straws this time glued to one another inserted through the nozzle... Result: more clarity in medium especially... I put this one near the wall behind my listening position...Bewilderment does not diminish,but I think now that I had touch the end of the road with these resonators...My best to all ...
I'm shocked you can put that many in your room. I put 5 in my room & it made the sound very thin. It provides better detail but sucks the life out of it. Yes, I've messed with location, opening size, throat length & the amount of water. I did find 2 spots in the room where it made the best difference, so I'm down to 2 of them with very small openings. I have several pounds of quartz on the walls & am thinking the 2 methods are not playing well together. Not done messing around with this yet though. No doubt it makes a difference, just not sure I like it...
Try the jerrican 5 gallons with 2 slush large straws inserted in one another and placed in the pierced  plastic sealed nozzle, that will equilibrate the frequencies toward the bass I promise... Just a little water in the jerrycan less than 10 %....It makes wonder all these resonators and by the way I use 20 types of stones and crystals in a connected grid on my audio system and in my electrical grid...All that push my system each times to more quality... But now it is I think impossible to makes all that I have sound better...
In audio price is not linearly connected to quality sound …. Tweaking already hi-fi used or vintage pieces of gear is the key to paradise...The Helmoltz resonators is astounding, but with some experiments... 
is your room already treated with absorber and reflector of sound? perhaps your room is already too much resonant and reflective and the resonator makes all that thin? My room was already treated by me before the adding resonators...There is some order to work with these tweaks...Room treatment first... Resonator second...
As some have suggested, could you post a picture of one of your actual resonators? Especially of the straw inserted, and how far into the plastic you have it inserted? You posted that you have "only the extremity of the straw at the top", and I am not sure what you mean by that. Thanks for your help and suggestions!
Simple if you experiment just a little... 2 inches max,  out of the nozzle...The straw  is only put trough the pierced plastic sheet paper wrap used in kitchen...I put elastic to tight it around the nozzle...No need of photo for that... And I cannot put photos here even if I wanted to...I apologize for that.... I will be here to answer your question...My best to you...
Placement is very important but simple... it takes me only few try and test to discover the best or almost best...The imaging can degrade or improve  with the placement of  only one of my 2 jerrycan...
After reading your room dimensions, I can now see where you can use that many with good effect. My ceiling is only 8' (in a basement). The room itself is not ideal at 15 X15. You are correct, it's been already treated with panels, acoustic disks, etc. At this point I'm just trying to tweak it by eliminating a smidgen of the "bloom" (it's not excessive) to get more detail. I'm making some progress with a smaller opening on the resonator. 
I am happy for your progress I wish you the best and I am here to discuss if you needed to...
Boxer12 I make a mistake in my room description the height is not 15 feet but 8 feet and 1/2 inches... Sorry
I have long had 4 Argent Room Lenses which are amazing by themselves, but, several years ago I attempted to take room resonance issues to a higher level

Being a cheap experimenter, I bought 6 3 gallon pails. I partially filled with h20 and moved them around the room. The result was definitely a nice improvement, but eventually the h2o evaporates AND in my case as mosquitos often get into my house during the rainy season, I was getting bitten alive, until I checked the pails one day and saw all manner of mosquito larvae in each

Still it worked great for a tiny investment
Hey, that reminds me! 🤗 Has anyone tried the water bowl tweak? Here’s how it works. You place three medium size bowls of *ice water* on the floor about two feet out from the speakers, one bowl in front of each speaker and one bowl between the other two, so the bowls of ice water are in a row left to right.
Geoff i think you are a bit less in shape than usual...You dont have mention the important fact to place ice cube regularly at each hour to gain the most!


Actually all you need to have is a temperature differential of 20 to 30 degrees F to hear the bowls of water. That means you can get by with cold tap water. Putting ice in the water is just uh, icing on the cake and to add some complexity. 😬 I debuted the bowls of water tweak at CES in the Golden Sound Room in 2005. My, how time flies! 🔙

Am I in shape now? 🏋🏻‍♂️
I hope my remark does not crucify you... Indeed you are in a better shape that I was thinking... Dont underestimate the beast it seems! thanks Geoff but I cannot try your tweak because my speakers are on my desk in nearfield litening ...
I experiment with 5 gallons glass bucket with 5 % water filled+ 2 thin straw inserted in the sealed nozzle with success for one and  2 slush larger straws for the other...Try with your own experiment and you will be amazed...
For those with enough disposable income, there are sets you can buy if you google it. Here's a link to a complete set of resonators but these are not for sale: https://utsic.utoronto.ca/wpm_instrument/helmholtz-resonators/
Just click on the photo to get a better view.

All the best,
Nonoise
Maybe you can try cups of ice water on the desk. 😬 Where there’s a will there’s a way.
I think I am done now... All is better, the dynamic, the natural instrumental timbre of instruments, the successive holographic layers of sound in an enveloping  fashion (I am in nearfield listening but the final result are way better also for room listening anywhere in the room)... I think that the varied bottles,carafes, jerrycans, and glass buckets, correct mutually each other their deficiencies and the final results are at my amazing satisfaction, with for example a bass clarity and depth incredible for my 7 inches Mission Cyrus 781 drivers...One year ago I dreamed to add a sub to my system, it is no more necessary, and absolutely without any more interest...I am done and bewildered more than yesterday...It is the end of this story...My best to all...
Geoff I am not enough clever to sort out if you mock me or want to help, probably the two in the same times ...But I like your spirit anyway... My best...
I cannot put even a glass of water in front of my speakers on the desk anyway.... Thanks for the suggested  experiment anyway...
I already had behind the speakers bottles of water... and near each speakers another one for resonators... It works...
The difference with your glass is that a straw is inserted in the bottle and they act as resonators better one I think that the open  glass...I dont doubt that anything near speakers affect speakers sound I know that by experience tough...
The cups of water need to be in front of the speakers. Have you put a resonator on top of the speakers yet? I once built a Helmholtz resonator that was fifteen feet long. 
My room has 15 feet lol.... On top of the speakers ok I will try that one day for sure thanks for the suggestion....I cannot try that now because of what I already had on top lol...And the sound now is too much better to dreaming improve it easily for the moment...