Dust or vapour, sure. So certainly a consideration in industrial applications. The solid material should be a non-issue. You'd need to vapourise, swallow or find some other way to properly ingest the stuff to have any health issues in a domestic setting. Of course, we probably all know a few who evaded the talent scouts of Colney Hatch & we're fairly sure go around licking windows when they think nobody's looking, so expensive tweeters probably aren't a huge step. 😉FYI Beryllium is toxic. I once interviewed at a company that made Beryllium domes for compression drivers. All the employees had to get yearly medical exams! It is really bad if the dust gets in your lungs. I'm all for great sound but not if it kills you.
A great number of things are bad for our lungs, including some that might surprise you.FYI Beryllium is toxic. I once interviewed at a company that made Beryllium domes for compression drivers. All the employees had to get yearly medical exams! It is really bad if the dust gets in your lungs. I'm all for great sound but not if it kills you.
https://www.aiha.org/news/240104-au... is set to become,and safety ministers on Dec.
Typical bureaucratic reaction. Someone got hurt at work, ban the stone! Seems to me they should improve the manufacturing process. It’s not like this is something new, people have been working around rock dust for thousands of years. There are known safe ways to handle dusty materials.
Thanks for these measurements of da mythical beasts, Jim
I'm not sure I would consider these units high quality. However, YMMV ... especially if you have zillion dB/8ve crossovers.
I have some curves for how low you need to get such resonances below audibility which IIRC are confirmed and reprinted by da false prophets Floyd & Olive 😊
I'm not sure I would consider these units high quality. However, YMMV ... especially if you have zillion dB/8ve crossovers.
I have some curves for how low you need to get such resonances below audibility which IIRC are confirmed and reprinted by da false prophets Floyd & Olive 😊
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Actually the directivity is a BIG part of our 1D sound. Da false prophets Floyd & Olive confirm our Jurassic work. I called it the Room Interface Profile and it might be the most important factor in the sound of a speaker in a room.I think @kgrlee pointed out that piston-like movement of cones compromises radiation pattern, not so much quality of the radiated sound in one dimension.
https://aes2.org/publications/elibrary-page/?id=3798
How do you measure da Room Interface Profile? Answers on a postcard please. This is a real question that obsessed me in much of my previous life 😊
I have seen this as I have mocked up some traced data to see how it acts. Any rigid cone requires a 2nd at minimum.If 1st order acoustical slopes etcl are your requirement for xyz reason, then rigid cones almost certainly aren't going to be suitable: that's just a classic case of mismatched characteristics & requirements.
Thank you for reinforcing this thought of mine
Start with a Klippel NFS. Modify it to your own taste. That should fit on a post card 🤣How do you measure da Room Interface Profile? Answers on a postcard please.
If you’d like to share those I’d be grateful.I have some curves for how low you need to get such resonances below audibility
I have some curves for how low you need to get such resonances below audibility
https://aes2.org/publications/elibrary-page/?id=2476If you’d like to share those I’d be grateful.
They're in the appendix of this paper, It's not only about Intermod Distortion. (long story) Alas, as a professional beach bum, I'm no longer an AES member. If you know a current AES member, you might secretly ask him. But be careful, as he could be excommunicated or worse by da AES Inquisition 😱
Might be easier to find it in da papers of false prophets, Floyd or Olive. They do reference us 😊
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How do you measure da Room Interface Profile? Answers on a postcard please.
Sure you can measure something.Start with a Klippel NFS. Modify it to your own taste. That should fit on a post card
In fact, "Absolute Listening Tests-Further Progress" tells us we can HEAR the RIP in the naive 1D measuring chain it describes. But how do we make sense of what we measure on this 1D chain.
When you refer to Toole and Olive as "false prophets", you lost me...
They sure are prophets to the general audience. But a lot of their findings weren’t new to insiders. The statistical proof they presented might well be though. Would be good to recognize we all stand on shoulders of giants.
Even so, calling anyone a false prophet should not be necessary, imho.
Even so, calling anyone a false prophet should not be necessary, imho.
Back down on 'da' planet Earth: please feel free to post them. Copyright law expressly allows fair use, i.e. selections from properly cited material. You can't simply copy a full article, but a page, some graphs or a paragrah or two of text for example are perfectly acceptable.They're in the appendix of this paper, It's not only about Intermod Distortion. (long story) Alas, as a professional beach bum, I'm no longer an AES member. If you know a current AES member, you might secretly ask him. But be careful, as he could be excommunicated or worse by da AES Inquisition 😱
I believe people should consider contract law, or get legal advice about this. Said material is behind a pay - wall. If you are a member of the AES, you pay for access, and part of that contract is that you are not permitted to re-distribute the material without authorization.Copyright law expressly allows fair use, i.e. selections from properly cited material. You can't simply copy a full article, but a page, some graphs or a paragrah or two of text for example are perfectly acceptable.
Payment to the AES forms the 'consideration' - monetary exchange. If there is no duress involved, and there is mutual consent, then the contract is valid.
Here's my two cents.
I've had good experiences with the ceramic coated aluminum drivers. Last week my two way speaker using the white cone SB 5" and white dome Visaton 1" dome, both ceramic coated aluminum, took first place in the two way category at the Pacific NW Audio Society Speaker contest. It's blind listening, not a beauty contest as all the others I'm aware of. The crossover is LR 4th order with notch at the high frequency breakup frequencies and baffle step correction. So these drivers will make the 1st order crossover gurus very disappointed. I think they are operating as a piston in this design with some dispersion control using a waveguide. In a multiway design it's not difficult to set the crossover frequency below the frequency where a driver starts to beam. It seems to me that the voice coil inductance value of many drivers is specifically set to counter the rise in response due to the narrowing directivity when driven by a low output impedance amplifier.
I think there can be some sounds associated with the cone material. Rub your finger across the cone and it will make a sound that is dependent on the material. That sound will be at a relatively high frequency for the stiff light weight carbon fiber, metal or ceramic cones. To excite that mode requires some energy getting delivered to the cone at that frequency. If the crossover steep and lower frequency there will be very little energy send to the motor at that frequency. However it would seem that non-linearity and asymmetry in the motor, suspension or surround can create harmonics of the drive signal that will excite that mode even when it's attenuated by the crossover. There is a lot of talk of rocking modes in low cost dome midranges causing problems for instance.
I have two pairs for sale if anyone is interested.
I've had good experiences with the ceramic coated aluminum drivers. Last week my two way speaker using the white cone SB 5" and white dome Visaton 1" dome, both ceramic coated aluminum, took first place in the two way category at the Pacific NW Audio Society Speaker contest. It's blind listening, not a beauty contest as all the others I'm aware of. The crossover is LR 4th order with notch at the high frequency breakup frequencies and baffle step correction. So these drivers will make the 1st order crossover gurus very disappointed. I think they are operating as a piston in this design with some dispersion control using a waveguide. In a multiway design it's not difficult to set the crossover frequency below the frequency where a driver starts to beam. It seems to me that the voice coil inductance value of many drivers is specifically set to counter the rise in response due to the narrowing directivity when driven by a low output impedance amplifier.
I think there can be some sounds associated with the cone material. Rub your finger across the cone and it will make a sound that is dependent on the material. That sound will be at a relatively high frequency for the stiff light weight carbon fiber, metal or ceramic cones. To excite that mode requires some energy getting delivered to the cone at that frequency. If the crossover steep and lower frequency there will be very little energy send to the motor at that frequency. However it would seem that non-linearity and asymmetry in the motor, suspension or surround can create harmonics of the drive signal that will excite that mode even when it's attenuated by the crossover. There is a lot of talk of rocking modes in low cost dome midranges causing problems for instance.
I have two pairs for sale if anyone is interested.
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All I can say is that the AES must operate under very different policies to every single academic journal I've worked or written for, if it attempts to prohibit even basic short quotes of material under standard fair use practice (i.e. it's a/ properly cited, and b/ not 'complete', as in you still need to purchase either journal or article as relevant to obtain the full argument, data & conclusions). I've actually yet to find the text in their regulations stating that no citation of any kind whatsoever is permitted. Perhaps somebody could point me to it?
Fair use is fair use, although the particulars differ from country to country. Very few, to none, academic journals are "behind a pay wall" because they're on the shelf of the university library. If they are not on the shelf of a research library then I'd question the quality of the journal.
Also, the author doesn't ALWAYS retain the rights because he may agree that the rights belong to the journal upon publication. But that is rare.
Also, the author doesn't ALWAYS retain the rights because he may agree that the rights belong to the journal upon publication. But that is rare.
Could you be a bit more specific as to "where, who, what"? And to what "low cost dome midranges" would this refer?There is a lot of talk of rocking modes in low cost dome midranges causing problems for instance.
Re citations, exactly. I can go down to an institution library tomorrow, select a volume of the AES and quote it reasonably (inc. proper citation) for fair use purposes under the national (or equivalent national) copyright regulations. I can also walk to my shelf, take one of the AES volumes I bought from a charity shop down & do the same. Or the same for a couple I saved from a skip. As far as I can see, the AES do not try to prevent such use. Here's a quote on the subject from one of their journals that I just randomly pulled off my shelf:
[Capitalisation, bold and italic per original source].
Lest anybody think I'm making that up, I've attached a screenshot from my 'phone below.
Journal of the Audio Engineering Society -Audio / Acoustics / Applications: Volume 29, Number 6 (June 1981), p. 393Copyright
Copyright © 1981 by the Audio Engineering Society Inc. It is permitted to quote from this Journal with customary credit to the source
[Capitalisation, bold and italic per original source].
Lest anybody think I'm making that up, I've attached a screenshot from my 'phone below.
Attachments
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I referenced one 2004 paper here titled "Sound source design in the very low frequency domain", Convention paper 6157
At the top it states "all rights reserved." Reproduction of this paper, or any portion therof is not permitted without direct permission of the Journal of the Audio Engineering Society.
Do as you like, but for at least 20 years it's not permitted to reproduce without permission.
At the top it states "all rights reserved." Reproduction of this paper, or any portion therof is not permitted without direct permission of the Journal of the Audio Engineering Society.
Do as you like, but for at least 20 years it's not permitted to reproduce without permission.
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