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Re: Small bell type of thingies on the speakers

May 24th, 2020, 10:21 am

Synergistic Research does sell tiny cups as Paul described. I think Kemper has some.

Re: Small bell type of thingies on the speakers

May 24th, 2020, 11:29 am

Just for grins I put together the following:

Approximate Wavelength of Audio Frequencies in Air:

20,000-Hz. approx. = 5/8-inch

15,000-Hz. approx. = 1-inch

10,000-Hz. approx. = 1-3/8-inch

8,000-Hz. approx. = 1-11/16-inch

5,000-Hz. approx. = 2-11/16-inches

3,000-Hz. approx. = 4-1/2-inches

2,000-Hz. approx. = 6-3/4-inches (1/2-foot)

800-Hz. approx. = 16-7/8-inches (1-1/3-foot)

400-Hz. approx. = 33-3/4-inches (2-3/4-feet)

100-Hz. approx. = 135-inches (11-1/4-feet)

50-Hz. approx. = 270-inches (22-1/2-feet)

30-Hz. approx. = 450-inches (37-1/2-feet)

20-Hz. approx. = 675-inches (56-1/4-feet)

Or - to put it perspective - we strive to eliminate unwanted resonances and distortions in our quest for good sound reproduction - why on earth would we even consider such device such as resonating bells and hollow metal cups?! :confusion-confused: I'm cornfused.

Re: Small bell type of thingies on the speakers

May 24th, 2020, 11:51 am

Walt,

What are you driving at by posting the wavelength chart?

Resonance frequency is not dependent upon the diameter of the resonating medium being equal to the wavelength. You don’t need 56’ drum to generate 20Hz sound wave.

Re: Small bell type of thingies on the speakers

May 24th, 2020, 11:57 am

Cogito wrote:Walt,

What are you driving at by posting the wavelength chart?

Resonance frequency is not on the diameter of the resonating medium. You don’t need 56’ drum to generate 20Hz sound wave.


If anyone can find out what frequency these gizmos resonant at they'll have an idea what effect they can have on the sound. As I said, we strive to eliminate unwanted resonances and distortions in our quest for good sound reproduction - why on earth would we even consider such device such as resonating bells and hollow metal cups?! :confusion-confused: I'm cornfused.

Re: Small bell type of thingies on the speakers

May 24th, 2020, 12:45 pm

SoundMods wrote:
Cogito wrote:Walt,

What are you driving at by posting the wavelength chart?

Resonance frequency is not on the diameter of the resonating medium. You don’t need 56’ drum to generate 20Hz sound wave.


If anyone can find out what frequency these gizmos resonant at they'll have an idea what effect they can have on the sound. As I said, we strive to eliminate unwanted resonances and distortions in our quest for good sound reproduction - why on earth would we even consider such device such as resonating bells and hollow metal cups?! :confusion-confused: I'm cornfused.


Helmholtz resonators can be used to tame peaks in sub-bass frequencies.

Re: Small bell type of thingies on the speakers

May 24th, 2020, 2:05 pm

Talk to Paul McGowen about Hemhilts Resonators on how uneffective they were when he built his first sound room for his RS-whatevers

Re: Small bell type of thingies on the speakers

May 24th, 2020, 6:40 pm

Came across this video.

https://youtu.be/Ck-fZJvf39M

Paul is using huge Helmholtz resonator to dissipate bass energy. My goal is to use the phase reversed energy yo cancel some of the energy at peaks, about 8-10dB. Small portable resonators will get the job done.

Re: Small bell type of thingies on the speakers

May 24th, 2020, 6:46 pm

Good luck

Portable Resonators

May 25th, 2020, 9:04 am

http://www.acusticaapplicata.com/polifemo.php?lang=eng

C3B431F7-C4DF-47AF-BDCD-B2E5A78CED7A.jpeg

Re: Small bell type of thingies on the speakers

May 25th, 2020, 10:07 am

whatever floats your boat... man
Get a sonotube and mount an old woofer
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