Absorbing traffic noise with Helmholtz resonators (video)

Very interesting exploration of Helmholtz theory and application. As someone who has had the opportunity to experiment with an Acustica Applicata Polifemo in a real world listening environment I can tell you that these really work and can eliminate unwelcome bass nodes and frequency anomalies without the use of signal degrading DSP filters or electronic equalization. Once properly positioned and tuned within the space the Polifemo simply and effectively smooths out the bumps that can intrude on the presentation. Highly recommended!

@hilde45 

Fascinating stuff! Thank you for posting.

I am involved with a number of horizontal drilling locations that either are inside cities or the cities are encroaching on us.  When you frac a well (and just drill a well) there are huge diesel generators (and pumps, and well, a giant drill) that humm along for a year.

Our noise is usually within a pretty fixed frequency range, so we've done a lot to address this.  Generally giant berms of dirt to reflect sound "up", coupled with large hanging helmholz panels several stories tall.

When the production phase is over, it's berms, some fixed relectors/resonators, coupled with natural absorption -- I like to plant Afghan pines and Texas live oaks (both keep their leaves all year and don't particularly require watering after being established after a year).  The pines are soft wood and the oak hard and do very different things to sounds.  But a triple row of mixed species does a lot, both in keeping things looking nice and absorbing the periodic banging of metal and trucks doing their thing.

We have several in residential neighborhoods.  It looks like a nice greenspace.

Planting buffallo grass also helps (a very tall native grass in west Texas, almost a bamboo) -- and it attracts a ton of wildlife -- unfortunately also rattlesnakes, which, in turn, like to hang out on concrete pads under warm diesel engines or cool metal sheds, depending on the time of year.

So that's a rather tough sell to workers.  LOL.  Don't blame them.

Interesting topic to me….I was not one of the naysayers who actually experimented with @mahgister bottle Helmholtz resonators.  I liked using 4 - 1.75L Bourbon or other bottles with long necks.  More is better but I had to control myself.  I added 1-2 inches of water, drilled holes in the caps and inserted various sizes (2-4 inches various diameters as well) of straws through the holes with a tight fit.  Set them up about halfway between the system and sitting position on an arc.  2 between the speakers and 1 outside of both speakers.  As crazy as this sounds it filled the room with a fuller more 3D sound bringing the music further into the room. It is a subtle improvement in my environment.  I only use  4 bottles so I can easy pull them out when I want to use them and no one is around.  My reputation to a hit when people saw Bourbon bottles spread throughout the room with straws in them.  🤣

Fun experiment.  Thanks Mahgister👍

Now imagine many tubes bottles ( 100 ) ,with various neck volume and lenght, from 8 foot to few inches, all tuned and located on the right spot (some near the speakers woofer or tweeter others beside or near me and some near wall reflecting location ) ...😁

I miss my crazy room where the soundfield were completely holographic as a completely surround system i even use foldable screen with devices on them etc ...

Now i am in near listening in a smaller acoustic corner but my system speakers are more accurate in the high  frequency response than my bigger Mission  and  because i modify the porthole design and the waveguide then i improve the bass and medium so much  i am glad too... And my headphone modified gave me a speaker soundfield... Then i enjoy 2 systems instead of only one now...

Helmhotz is the greatest modern acoustician...😊 I will put dr. Choueiri beside him ... And Dr. Gorike founder of AKG and the designer of my hybrid headphone : akg K340 ...

Fun experiment. Thanks Mahgister👍