Talk:Helmholtz resonance

Something is wrong with the math-markup language - it's not rendering correctly. — Preceding unsigned comment added by RichardNeill (talk • contribs) 02:22, 17 April 2011 (UTC)

Djembe

The claim about the djembe having been used 3000 years ago is pure speculation. We simply don't know how old the drum is. It is often associated with the Mali Empire (1200 AD) and the spread of the Numu (blacksmiths) across West Africa, but there is no proof of its existence prior to colonial times. It probably is at least several centuries old, but we simply don't know how old. Probably best to say "centuries" old instead. --MichiHenning (talk) 22:22, 15 April 2012 (UTC)

Reworded the relevant sentence accordingly. --MichiHenning (talk) 22:22, 16 May 2012 (UTC)

Length of neck

per Kinsler et al. the neck length needs to be corrected for the radius of the neck. For unflanged neck L' = L + 1.4a where a->neck radius. Comparing to FEA I can confirm that the corrected length is needed to get the resonant frequency to come out right. — Preceding unsigned comment added by 167.100.118.140 (talk) 15:32, 16 May 2012 (UTC)

See Acoustic resonance#Resonance of a sphere of air (vented). HLHJ (talk) 03:25, 2 June 2019 (UTC)

this editor

https://en.wikipedia.org/wiki/Special:Contributions/OnBeyondZebrax is making edits that are not constructive to the Helmholtz resonance. ::OnBeyondZebrax the edit is not explaining Helmholtz resonance. 73.193.195.69 (talk) 12:44, 16 September 2015 (UTC)

Again, today, same thing. https://en.wikipedia.org/wiki/Special:Contributions/OnBeyondZebrax is making edits that are not constructive to the Helmholtz resonance. ::OnBeyondZebrax the edit is not explaining Helmholtz resonance. CombatMarshmallow (talk) 21:16, 16 September 2015 (UTC)

The section of the article where the new material was proposed is titled "Applications". This section is about how Helmholtz resonance is applied in actual situations. In addition to discussing the application of Helmholtz resonance to engines and speakers, the "Applications" section had a sentence about the role Helmholtz resonance plays in guitars and violins. The purpose of the "Applications" section is not to explain Helmholtz resonance. The purpose of the "Applications" section is to describe actual applications. The proposed material CombatMarshmallow reverted was: "On the guitar and violin, the "...lowest resonance (associated with the Helmholtz resonance) falls near the pitch of the second lowest string, and the lowest body mode falls near the pitch of the third lowest. Together these increase the sound radiation at fundamentals of several of the notes in the low range of the instrument[s]."". This adds new information about the role that Helmholtz resonance plays on the guitar and violin, as it indicates that the Helmholtz resonance and the lowest body resonance "increase the sound radiation...of the notes in the low range of the instrument."OnBeyondZebrax • TALK 02:16, 17 September 2015 (UTC)

right thats not about the Helmholtz resonance. Id say with fairly high accuracy you know why it was reverted. Yet you are here. Anyhow coffee is Great and Im enjoying it thoroughly. Have a good one. Until next time.CombatMarshmallow (talk) 03:31, 17 September 2015 (UTC)

Here is an excerpt from the proposed sentence with the term "Helmholtz resonance" bolded: "On the guitar and violin, the "...lowest resonance (associated with the Helmholtz resonance)..." [bolding added]. It appears that the added text is discussing Helmholtz resonance. ThanksOnBeyondZebrax • TALK 16:17, 17 September 2015 (UTC)

This is a generalization page. Just like the other edits you were doing. Thats not about Helmholtz resonance in general. It should be general and focus mostly on Helmholtz resonance such as what is there already, "In stringed instruments, such as the guitar and violin, the resonance curve of the instrument has the Helmholtz resonance as one of its peaks, along with other peaks coming from resonances of the vibration of the wood." CombatMarshmallow (talk) 17:19, 17 September 2015 (UTC)

I encourage other editors to read the "Applications" section, which describes how Helmholtz resonance is used in lots of practical, specific circumstances, including in car and aircraft engines, ocarinas, guitars and violins, and djembe drums. Could another editor please review this issue? Thank you😊OnBeyondZebrax • TALK 20:42, 18 September 2015 (UTC)

I don't understand what exactly was objectionable about the edit. It seems to describe how Helmholtz resonance is relevant to construction of string instruments. Does anyone object to adding it back in? Esn (talk) 08:10, 2 January 2017 (UTC)

reed-less 2-strokes ?

This quote "In some two-stroke engines, a Helmholtz resonator is used to remove the need for a reed valve. A similar effect is also used in the exhaust system of most two-stroke engines, using a reflected pressure pulse to supercharge the cylinder (see Kadenacy effect.)" looks very dubious to me. #1 if there are reed-less 2-strokes which are not using some kind of other shutter or piston to act as a reed valve, I want to know about them, I can't find anything. #2 "exhaust system ... reflected pressure pulse to supercharge the cylinder" is not Kadency effect or anything like it, it's momentum of exhaust which draws a vacuum in the cylinder pulling in air/fuel, not pressure. FYI commit which added it: https://en.wikipedia.org/w/index.php?title=Helmholtz_resonance&diff=prev&oldid=463400628 Cjdelisle (talk) 18:40, 12 April 2016 (UTC)

Why pitch changes with blowing pressure

Hi, perhaps I missed it, but does this article explain why and how the note's pitch rises when air is blown faster into a Helmholtz resonator, until it eventually stops sounding altogether? The range can be several semitones, depending on how large the opening area is relative to the chamber volume. Is there an equation here explaining it? Esn (talk) 07:52, 2 January 2017 (UTC)

Hi, Esn. Try Vessel flute#Acoustics, which admittedly does not explain it directly, but suggests an answer. If anyone has a source for this it should probably be added to both articles. HLHJ (talk) 03:22, 2 June 2019 (UTC)

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Vitruvius

Vitruvius (first century BC engineer) wrote of acoustics and the use of what seem to be Helmholtz resonators in theater design (Book 5, "Sounding vessels in the theater"). Does anyone have any sources on this, or on Helmholtz resonators in contemporary acoustic design? It's mentioned as a way to reduce undesirable resonances under Helmholtz resonance#Applications, but that's all. HLHJ (talk) 03:40, 2 June 2019 (UTC)