Bill Cain Posted June 16, 2006 Share Posted June 16, 2006 PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. Sounds scarey. Anyone from Klipsch confirm this? Please excuse my scepticism when first hearing of something that sounds like an urban legend. For a discussion about Be diaphragms without the skull and crossbones, see: http://www.audioasylum.com/scripts/t.pl?f=general&m=435202 Exploding, Killer Diaphragms sound like something a company which does not use Be would float. Heck, even JBL makes 'em. I find the idea of a mechanical impact, within a driver, vaporizing Beryllium foil.... unlikely. I am open to the idea if it has been documented, somewhere........ anywhere. Your call...... [] Quote Link to comment Share on other sites More sharing options...
steamer Posted June 17, 2006 Author Share Posted June 17, 2006 PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. 4001 is rated at 60W with a 650hz 12dB crossover. So,do you think I could slam the diaphram into the phase plug at 2 watts max output? LOL! That's what I was thinking also. Didn't I read somewhere a while back that PWK used to use Crown amps on everything? If so, it's no wonder that he blew those TAD drivers and whatever else drivers he had laying around. [] I guess Crown amplification would be the acid test for any driver! Greg Quote Link to comment Share on other sites More sharing options...
Bill Cain Posted June 17, 2006 Share Posted June 17, 2006 Why do you think they coat them? Funny you should ask...... again..... [] The first time was on the Lansing Heritage Forum, a while back. I'm surprised you forgot. 09-24-2004, 07:25 AM #30 Maron Horonzakz DON...... If the 475.....2450 type drivers using coherent wave phazing plugs were really designed for Be .... Why the odd 2450SL powder coat aquaplas diaphram as used in the JBL K2 95000 ? What was that coating supposed to do. And why the smooth coat rather than the ribbed pattern? (http://www.audioheritage.org/vbulletin/showthread.php?t=2861&page=2) 09-24-2004, 08:50 AM #31 Don McRitchie The aquaplas coating is intended to damp resonances within the titanium diaphragm. I'm guessing that the ribs, while stengthening the diaphragm at high output, create phase anomalies of their own due to the ridges in the otherwise spherical surface. It was probably not felt to be an issue in pro applications, but became a concern in hi-fi use. FYI, JBL was using the aquaplas coating on their ribbed pro titanium diaphragms for a time, but I don't think they are now. I'm not sure why they stopped. __________________ Regards Don McRitchie Webmaster (http://www.audioheritage.org/vbulletin/showthread.php?t=2861&page=3) I would humbly suggest that any coating of a metal diaphragm is for damping purposes and not to prevent the dreaded Exploding, Killer Diaphragm Syndrome. Of course, I could be wrong; dead wrong. [] If so, kindly point me in the direction of proof. I don't wish to die in such a scenario.http://www.audioheritage.org/vbulletin/showthread.php?t=2861&page=2'> Quote Link to comment Share on other sites More sharing options...
steamer Posted June 17, 2006 Author Share Posted June 17, 2006 Why do you think they coat them? Funny you should ask...... again..... [] The first time was on the Lansing Heritage Forum, a while back. I'm surprised you forgot. 09-24-2004, 07:25 AM #30 Maron Horonzakz DON...... If the 475.....2450 type drivers using coherent wave phazing plugs were really designed for Be .... Why the odd 2450SL powder coat aquaplas diaphram as used in the JBL K2 95000 ? What was that coating supposed to do. And why the smooth coat rather than the ribbed pattern? (http://www.audioheritage.org/vbulletin/showthread.php?t=2861&page=2) 09-24-2004, 08:50 AM #31 Don McRitchie The aquaplas coating is intended to damp resonances within the titanium diaphragm. I'm guessing that the ribs, while stengthening the diaphragm at high output, create phase anomalies of their own due to the ridges in the otherwise spherical surface. It was probably not felt to be an issue in pro applications, but became a concern in hi-fi use. FYI, JBL was using the aquaplas coating on their ribbed pro titanium diaphragms for a time, but I don't think they are now. I'm not sure why they stopped. __________________ Regards Don McRitchie Webmaster (http://www.audioheritage.org/vbulletin/showthread.php?t=2861&page=3) I would humbly suggest that any coating of a metal diaphram is for damping purposes and not to prevent the dreaded Exploding, Killer Diaphram Syndrome. Of course, I could be wrong; dead wrong. [] If so, kindly point me in the direction of proof. I don't wish to die in such a scenario.http://www.audioheritage.org/vbulletin/showthread.php?t=2861&page=2'> Interesting development,maybe I'm not going to listen with hazardous materials as I thought or not AS hazardous as I thought? Greg Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted June 17, 2006 Share Posted June 17, 2006 PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. Exploding, Killer Diaphrams Exploding Diaphrams ..... Pure Freakin' B.S. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted June 17, 2006 Share Posted June 17, 2006 Actually, ifn' the Berillyium was so hard as to be frangible.... it could never be formed nto a diaphram Quote Link to comment Share on other sites More sharing options...
Bill Cain Posted June 17, 2006 Share Posted June 17, 2006 PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. Exploding, Killer Diaphragms Exploding Diaphragms ..... Pure Freakin' B.S. Gee, ya think? [] LMAO!!!! PWK's little yellow button still speaks loudly. Do they still make them? Quote Link to comment Share on other sites More sharing options...
Deang Posted June 17, 2006 Share Posted June 17, 2006 So,do you think I could slam the diaphram into the phase plug at 2 watts max output? Well, you're talking about running the driver a full octave below it's recommended crossover point, and that's a lot energy being sent to something that wasn't designed for it. Also, you're assuming a clean 2 watts, and considering that what you're using amounts to nothing more than a pair of distortion generators .... What does it matter, it's simply the wrong driver for the application. You can cheat things a little, but you can't cheat them a lot. PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. The material is brittle as hell. It's thin, and when it goes -- it goes like glass. See page 7, section i http://www.lle.rochester.edu/pub/documents/ext/6706E.pdf Quote Link to comment Share on other sites More sharing options...
ZAKO Posted June 17, 2006 Share Posted June 17, 2006 If you dont believe me about Be being dangerous...Crank one up, blow it, then take a sniff. I didnt warn you just to get in a pissing contest. I would never use the TAD 2001 Below 800hz On the Heritage forum i never got a valid answere as to coating the diaphram with aquaplas. Resonence distortion of diaphram seemed unlikly at normal listening levels. But coating of diaphrams will reduce dust to a lower level. If an accedent should happen. Manufacturing the diaphrams is an interesting process. And costly. $500 to $ 700. each. JBL did not stop making Be diaphrams, as Don is mistakin. JBL makes the 435Be, 2435Be, 0435Be all aquaplas coated. Quote Link to comment Share on other sites More sharing options...
Bill Cain Posted June 17, 2006 Share Posted June 17, 2006 PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. The material is brittle as hell. It's thin, and when it goes -- it goes like glass. See page 7, section i http://www.lle.rochester.edu/pub/documents/ext/6706E.pdf i. Handling procedures for diagnostics and other equipment incorporating beryllium filters or windows: Thin beryllium windows (usually around 1 mil, or 25 µm thick), such as those found on x-ray cameras, are extremely brittle and can be shattered with a seemingly insignificant amount of touch pressure (e.g., lightly wiping with a tissue). In a system either above or below ambient pressure, there can be a substantial risk to personnel from beryllium fragments and particulates that would be generated in the event of a window rupture. For systems under vacuum, a stressed beryllium window will implode and any flying fragments will be contained within the apparatus and vacuum system, causing damage to sensitive components and requiring decontamination of the system from beryllium fragments and particulates. A greater danger to personnel from flying beryllium shards and particulates exists if the window was to rupture outward due, for instance, to a pressure buildup in a cryostat, which can occur if the cryostat develops a vacuum leak while at low temperature and is then allowed to warm up. (1) Under no circumstances are beryllium windows under vacuum or pressure ever to be wiped, cleaned, or contacted in any way. If it is determined that cleaning the window is necessary, the apparatus containing the window must be vented to room pressure before such operations can proceed. (2) Cryostats used with equipment containing beryllium windows must have a pressure relief valve to prevent an outward rupture of the window in the event of an intended or unintended warm-up of the cryostat. As a secondary precaution, the window should be covered with a plastic or metal cap when the apparatus is not in use to confine beryllium debris in the event of an unexpected window failure. ? I'll remember this when using an X-Ray camera. [] Quote Link to comment Share on other sites More sharing options...
Deang Posted June 17, 2006 Share Posted June 17, 2006 Well, some of you thought the idea of a "shattered diaphragm" was over the top -- but there it is. If 1 mil thick beryllium can can be "shattered" by "lightly wiping with a tissue", then it shouldn't take much to understand what will happen if a beryllium diaphragm hits a phase plug -- unless of course you choose to be obtuse. Quote Link to comment Share on other sites More sharing options...
Bill Cain Posted June 17, 2006 Share Posted June 17, 2006 If you dont believe me about Be being dangerous...Crank one up, blow it, then take a sniff. I didnt warn you just to get in a pissing contest. No pissing contest from here. I merely used your own words, from another forum, to illustrate that you had prior knowledge of the reason for coating metal diaphrams. Your reply, here, ("Why do you think they coat them?") might incorrectly lead one to think the coating was a "safety" issue. [] Well, some of you thought the idea of a "shattered diaphragm" was over the top -- but there it is. If 1 mil thick beryllium can can be "shattered" by "lightly wiping with a tissue", then it shouldn't take much to understand what will happen if a beryllium diaphragm hits a phase plug -- unless you're obtuse of course. ROTF!!! An X-Ray camera window, under pressure from a vacuum chamber, is not a TAD 2001 diaphragm. []<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Pejorative comments do not deflect scrutiny of pointless (and misleading) references and will not deter honest observations of same. PWK tested the TAD and had one hit the phase plug, shatter, and turn to dust. I'm still looking for evidence of that. This is one interesting thread......... [8-|] Quote Link to comment Share on other sites More sharing options...
steamer Posted June 17, 2006 Author Share Posted June 17, 2006 Well, you're talking about running the driver a full octave below it's recommended crossover point, and that's a lot energy being sent to something that wasn't designed for it. Also, you're assuming a clean 2 watts, and considering that what you're using amounts to nothing more than a pair of distortion generators .... What does it matter, it's simply the wrong driver for the application. You can cheat things a little, but you can't cheat them a lot. The spec sheet says 500hz-20khz,a tech in the TAD divsion says 500 w/24 db slope is ok,hey he might not know his head from his ...I understand what you are saying here about a possible wrong application.I read an interview with Dr.Bruce Edgar where he talks about using the 2001 in a 300hz mid horn.He says: Bruce: Well, there are two areas. I've been doing experiments with round horns. I've done 300-Hertz, round midrange horns for a number of different drivers such as the Altec and the TAD 2001. http://www.positive-feedback.com/Issue4/edgarinterview.htm I saw a few other references to a lower x-over point yesterday,cant find them at this time but it seems to have been done. I have my x-over on my Rane at 650hz as of yesterday.I am trying to get a feel for the sound and see how I like it.Its definately different than what I am used to. Greg Quote Link to comment Share on other sites More sharing options...
steamer Posted June 17, 2006 Author Share Posted June 17, 2006 Well, some of you thought the idea of a "shattered diaphragm" was over the top -- but there it is. If 1 mil thick beryllium can can be "shattered" by "lightly wiping with a tissue", then it shouldn't take much to understand what will happen if a beryllium diaphragm hits a phase plug -- unless of course you choose to be obtuse. Here is an interesting link on the history of TAD and some applications.Check out the pic of all those TAD drivers hanging over the crowd with cranes.What kind of power are they pumping into them and if the soundman gets that x-over wrong and they do shatter...well lots of people below. http://www.reyaudio.com/history-e.html just a thought Greg Quote Link to comment Share on other sites More sharing options...
Deang Posted June 17, 2006 Share Posted June 17, 2006 ROTF!!! An X-Ray camera window, under pressure from a vacuum chamber, is not a TAD 2001 diaphragm. No it's not, but you keep missing the point. Beryllium is metallized glass, is brittle, and will shatter -- just like glass. Believe whatever you want. Quote Link to comment Share on other sites More sharing options...
filmboydoug Posted June 17, 2006 Share Posted June 17, 2006 I assume there are many thousand Be drivers out there. Is there any evidence, anecdotal or otherwise, of anyone ever being injured by a busted diaphram? Quote Link to comment Share on other sites More sharing options...
Deang Posted June 17, 2006 Share Posted June 17, 2006 Yeah, I hear some cause hearing damage. Quote Link to comment Share on other sites More sharing options...
steamer Posted June 17, 2006 Author Share Posted June 17, 2006 ROTF!!! An X-Ray camera window, under pressure from a vacuum chamber, is not a TAD 2001 diaphragm. No it's not, but you keep missing the point. Beryllium is metallized glass, is brittle, and will shatter -- just like glass. Believe whatever you want. Dean, I understand your point here.You also spoke of the correct application and I understand that.The question would seem to be is the 500hz cross point a wrong application?According to TAD it is not.I am sure there are limitations at 500hz.Hey I dont want to blow a $350 driver.I posted this thread for info on my idea for this application.I have to say there are some good thoughts here.Thanks I just wonder why TAD would make such a fragile product then give specs like 500-22k response.Granted with a recommended 800hz cross. Greg Quote Link to comment Share on other sites More sharing options...
Bill Cain Posted June 17, 2006 Share Posted June 17, 2006 Beryllium is metallized glass, is brittle, and will shatter -- just like glass. Believe whatever you want. LOL I believe that which has been proven. Metallized Glass is a term used to describe vacuum deposited thin film coatings for glass, including fiber optic components. Typical coatings may include front & back surface aluminum, gold & silver mirrors; dichroic filters; long & short wave pass filters; beamsplitters; low reflection coatings for 200-2000nm; heat absorbing films, & transparent conductive coatings. Your windows may be coated to reflect heat energy and not light. Beryllium, OTOH, is an alkaline earth metal, many compounds of which are toxic. Discovery of the element, in the mineral beryl, was by Nicolas Louis Vauquelin in 1789. Beryllium metal was first isolated by Wöhler and Bussy in 1828. One little known fact: the speed of sound in beryllium (12,500 m/s) is greater than in any other element. It seems to make pretty good diaphragms, mainly because of its' light weight and rigidity. Perhaps one should learn the difference between Beryllium and Metallized Glass before ascribing the qualities of one to the other? [] I'm still waiting for someone from Klipsch, or anyone with a modicum of credibility, to confim that a Beryllium diaphragm was / can be "turned to dust" through overdriving. I remain open to that possibility, when proven, but will reject bullshit when proffered. Quote Link to comment Share on other sites More sharing options...
Bill Cain Posted June 17, 2006 Share Posted June 17, 2006 [] The spec sheet says 500hz-20khz,a tech in the TAD divsion says 500 w/24 db slope is ok,hey he might not know his head from his ...I understand what you are saying here about a possible wrong application.I read an interview with Dr.Bruce Edgar where he talks about using the 2001 in a 300hz mid horn.He says: Bruce: Well, there are two areas. I've been doing experiments with round horns. I've done 300-Hertz, round midrange horns for a number of different drivers such as the Altec and the TAD 2001. http://www.positive-feedback.com/Issue4/edgarinterview.htm I saw a few other references to a lower x-over point yesterday,cant find them at this time but it seems to have been done. I have my x-over on my Rane at 650hz as of yesterday.I am trying to get a feel for the sound and see how I like it.Its definately different than what I am used to. Greg The horns may have an inate 300Hz lower limit, but I believe the crossover point for the driver is higher. As Bruce says: << The 300-Hertz horn that I make turns on at around 400 Hertz, and since its size is not huge, I can build a full-size 300-Hertz horn. It sounds very nice, but it won't turn on until 400 Hertz. >> The main thing I got out of his interview it that you must experiment. I'd start with the TAD 2001 and work from there. Bruce says this, also: << Recently, at the urging of a customer, I tried out the TAD 2001 1-inch compression driver on my round horn. It has to be the best horn driver ever made. The response has great transparency and depth. Most of the 2-inch compression drivers have no depth of image at all. The TAD 2001 is now incorporated in my System 50. >> Best of luck with your efforts. [Y] Quote Link to comment Share on other sites More sharing options...
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