[Boatanchors] Do Headphones Age-Away?

[1oldlens1]

Without the magnet the diaphragm will tend to respond to each alternation of the current, I. E. Will tend to respond to the second harmonic of the driving signal.The magnetic telephone receiver was invented by a. G. Bell and has differed little in design while it relatively simple the mathematical analysis is quite complicated.  The older books like "elements of acoustical engineering", H F Olson, have some coverage. My main computer has layed an egg so I am without patent references.Sent from my Galaxy
-------- Original message --------From: Brian Clarke <brianclarke01 at optusnet.com.au> Date: 8/13/22  7:22 PM  (GMT-08:00) To: hwhall at compuserve.com, boatanchors at mailman.qth.net Subject: Re: [Boatanchors] Do Headphones Age-Away? Just consider the magnet strength. I reckon it would be impossible for any electrical signal to the coils to move the diaphragm to convex. The induced magnetic force would have to exceed that of the permanent magnet.73 de Brian, VK2GCE-----Original Message-----From: boatanchors-bounces at mailman.qth.net [mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of hwhall at compuserve.comSent: Sunday, 14 August 2022 12:15 PMTo: boatanchors at mailman.qth.netSubject: Re: [Boatanchors] Do Headphones Age-Away?It is my understanding from reading old documents that its not correct that the permanent magnet is there to "hold the diaphragm in place" - or at least not the way that reads to me.  It puts a mechanical bias on the diaphragm, making it concave (pulled toward the magnet) so that the induced motions of creating sound never take the diaphragm through flat to convex.  The transition between concave to convex was said to induce buzzing.WayneWB4OGM-----Original Message-----From: Brian Clarke <brianclarke01 at optusnet.com.au>To: 'Al Klase' <ark at ar88.net>; boatanchors at mailman.qth.netSent: Sat, Aug 13, 2022 8:05 pmSubject: Re: [Boatanchors] Do Headphones Age-Away?I think you'll find that the permanent magnet is there only to hold the diaphragm in place. I cannot see how increasing the magnet strength would increase the audio loudness. The amount of variation in magnetic force to move the diaphragm is probably a thousandth of the permanent magnet's strength.73 de Brian, VK2GCE.-----Original Message-----From: boatanchors-bounces at mailman.qth.net [mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of Al KlaseSent: Sunday, 14 August 2022 2:02 AMTo: boatanchors at mailman.qth.netSubject: Re: [Boatanchors] Do Headphones Age-Away?Jeo Conner said:  Sometimes, it's simply the "aging" of our ears. LOL.That's not a joke.  I tested some headsets back in 1997.http://www.skywaves.ar88.net/xtalset102/headsets.htmI repeated the tests with some of the same 'phones last year.  I'm about 10 dB down.That said, it may be possible to spiff up the classic metal diaphragm 'phones by stroking the pole pieces with a strong (Chinese) rare-earth magnet.AlARK Sig Block Al Klase - N3FRQJersey City, NJhttp://www.skywaves.ar88.net/ ______________________________________________________________Boatanchors mailing listHome: http://mailman.qth.net/mailman/listinfo/boatanchorsHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Boatanchors at mailman.qth.netList Administrator: Gary Harmon, K5JWK** For Assistance: gharmon at idworld.net **This list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.htmlMessage delivered to hwhall at compuserve.com ______________________________________________________________Boatanchors mailing listHome: http://mailman.qth.net/mailman/listinfo/boatanchorsHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Boatanchors at mailman.qth.netList Administrator: Gary Harmon, K5JWK** For Assistance: gharmon at idworld.net **This list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.htmlMessage delivered to brianclarke01 at optusnet.com.au ______________________________________________________________Boatanchors mailing listHome: http://mailman.qth.net/mailman/listinfo/boatanchorsHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Boatanchors at mailman.qth.netList Administrator: Gary Harmon, K5JWK** For Assistance: gharmon at idworld.net **This list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.htmlMessage delivered to 1oldlens1 at ix.netcom.com