Egyptian priests used resonators to "equalize" room temple sound... Before Hemlholtz..
I had 100 because i conducted experiments for many years with no cost materials from tube 8 feet high and large and straws and all dimensions in between.. I tuned them by ears...it takes me 2 years to complete 7 day/7...( Acoustics was my hobby then ) Way more fun than throwing money on a new dac because we are unsatisfied...
One single straw as part of a resonator mouth located at the right place create an audible effect...The location of the resonators matter too not only their dimension and cross ratio.. I also use them in a way to make a kind of mechanical crossfeed too for the speakers with some near the drivers...( i could not suppress crosstalk anyway in my room then i turned this impotency into and advantage i designed my version of mechanical crossfeed)
Now i dont own my past room, i must had sold my house but i used Helmhotz principle to modify my now small speakers vent hole because they are badly designd on all speakers for esthetical reason and cost...I modified my headphone too ...
For the measures:
you know that timbre is not a simple addition of pure frequencies because the ears perceive sound in his own time dimension. Timbre is a set of large band...
I used my ears to tune to my liking all my resonators in fonction of the timbre i wanted for the musical instruments like we tune a piano...My ears "measures" them one at times..each one compensate for others... There is a trade-off...
When all was completed my stereo system completely vanished..
My prefered opera Kurt Weill 4 penny opera soundfield was around me with natural timbre...
The singers walking and singing i was able to "see" their head turning...And sometimes singing next to my chair or near my shoulder...
Dr . Choueiri call that the spatial attributes of sound...H3e described them in his articles..
if you think that you can have this with one resonators or 2 sorry no...It is why without knowing what i did at the begining i add one at a time, each time gaining better S.Q, with each tuning.
but if you buy the BACCH system it will do this in a perfectly controlled way...
I called my resonators set a mechanical equalizer because it is exactly what it was...
The equalization process was tuned for my ears not by an electrical means...
The BACCH system will be better for sure but i know what it will do because i made it mechanically...
But some aspects cannot be made mechanically, as the measures of HRFT, or the control of the crosstalk cancellation etc...
It is why studying acoustics reading about sound perception is more valuable than reading reviewers who most of the time dont know really more about acoustics concepts than the customers who listen to them ..
It is why people invest big money in this hobby often without knowing what they do as an obsession..
i prefered to inform myself...
I was fascinated at some point by theoretical acoustics... What is sound... I discovered not only Dr. Gorike genius reading his patent about my headphone, not only Dr. Choueri genius insight into spatial aspects of sound control but a genius in pure acoustics theory i read in ectasy... He explain sound perception like no one else ... This is another story... I posted about it in a thread about spiritual aspect of music...( i posted many scientific articles about acoustics there but very few were interested in spite of the fact that there is a revolution in acoustics and sound perception right now)
In life i am mostly interested by mathematics,linguistic,philosophy and acoustics and their relation...
I sure know what a tuned resonator is, higher end studios tend to use them as they can be made more discreet....had one in a former house, found something more broadband and better in recent times.
When you said you had a 100 Itty bitty ones that served as a "mechanical room equalizer", it started to sound a lil kookalicious.
On the same note, the effect of one can be clearly measured. I suppose you didn’t get that far or did you? Or did the effect of a cluster 100 whatever...of them do a number on ya?