Guys,
According to Usher and Stan "the high dawg", Dr. D'Appolito is a consultant.
Well, Dr. Joe has written to me and stated that he has not been affiliated with Usher since 2005 and had no knowledge of the source or origin of the gray domes!
Now if you visit www.usher.com or www.usherusa.com you will be lead to believe that Usher is working with Dr. Joe.
Dr. Joe is Chief Engineer with Snell Acoustics. Dr. Joe has requested that Usher remove his name from their websites and issue a statement that Dr. Joe has terminated his relationship with Usher.
According to Usher and Stan "the high dawg", Dr. D'Appolito is a consultant.
Well, Dr. Joe has written to me and stated that he has not been affiliated with Usher since 2005 and had no knowledge of the source or origin of the gray domes!
Now if you visit www.usher.com or www.usherusa.com you will be lead to believe that Usher is working with Dr. Joe.
Dr. Joe is Chief Engineer with Snell Acoustics. Dr. Joe has requested that Usher remove his name from their websites and issue a statement that Dr. Joe has terminated his relationship with Usher.
SY said:
I'm guessing some grade of acetone. I wouldn't know what the high pressure liquid was though, though it's like that if the process was super critical that CO2 was used.
I think the stickiness is simply the result of quicker/cheaper method of form-drying for this application. It may even be beneficial at higher freq.s utilizing the resulting viscoelastic surface to damp the membrane. Having looked closely at it I'm almost positive it is not a coating, so I *think* this is basically what's going on with this material.
Chances are though that (even excepting the surface) that it isn't purely an aerogel, perhaps more succinctly an aerogel/xerogel combination because I think it's highly likely that the process involved some measure of shrinking.
Though it may also have no relavance, it is interesting to note that the high pressure liquid CO2 process was invented almost 2 decades before the Audax Aerogel drivers were being produced.
Oh well, bit off-topic..
mowry said:
I looked at their use of his name, it was *craftily* altered depending on the product. Ex.(s):
BE-20:
"Dr. Joseph D'Appolito is our technical consultant providing guidance on crossover design"
Perhaps true for that particular loudspeaker when it was first designed.
BE-718:
"Just how global is our design project? The high technology drivers, crossovers, and perfectly timed-aligned cabinets are designed and built by Mr. Tsai Lien Shui at Usher Taiwan, with finishing cosmetics supplied by a firm in the United Kingdom. Dr. Joseph D'Appolito, Usher's long-serving technical consultant, provides crossover tuning here in the 'States.
Notice how "our design project" may not have anything directly related to the BE-178. Nor does it state that Joe is *currently* serving as a technical consultant, or providing *current* crossover tuning in the US.
CP-6311:
"..Joseph D'Appolito-approved bi-wire/bi-amp crossovers.."
If he approved of that with some designs he actually consulted on, then why shouldn't he necessarily approve of that here?
He really should have a good lawyer take a look at his contract with Usher. None of it arises to blatant lie, but in "totality" any reasonable person would believe he was still working with Usher.
Sure, Usher does in fact make some good products - regardless of the material used. But the fact remains that their is more than a hint of hinky marketing behavior going on here. On the other hand most Co's are guilty of this to some extent, BUT this shouldn't let the Co "off the hook" when they do this.
Here's the "Truth" from Dr. Joe.
The last product I designed for them was the original X-718BE in 2005.
I requested that they no longer use my name in connection with any products they developed after that date nor any products I did not design during my association with them.
If my name has come up in any way relating to the current issue regarding the BE tweeter, it is without my knowledge or approval.
Here's what Usher says.
http://www.usheraudio.com/profile-D'Appolito.html
Copy paste with fix (h & w):
ttp://74.125.153.132/search?q=cache:QBvn779NZ5AJ: ww.usheraudiousa.com/company-information.php5+usher+audio+D%27Appolito&cd=3&hl=en&ct=clnk
The last product I designed for them was the original X-718BE in 2005.
I requested that they no longer use my name in connection with any products they developed after that date nor any products I did not design during my association with them.
If my name has come up in any way relating to the current issue regarding the BE tweeter, it is without my knowledge or approval.
Here's what Usher says.
http://www.usheraudio.com/profile-D'Appolito.html
Copy paste with fix (h & w):
ttp://74.125.153.132/search?q=cache:QBvn779NZ5AJ: ww.usheraudiousa.com/company-information.php5+usher+audio+D%27Appolito&cd=3&hl=en&ct=clnk
I do not have any Be drivers to compare, but I do have a few other metal drivers. All direct radiating tweeters. So if you wish that my data be compared with yours, there is not way it can be comparible without resonable doubt. If you have compression driver data, I'm sure lots of people would like to see it, but it does not seem to have any relation with whether I post data or not. If anyone has direct radiating tweeter data, then I can provide my data as a comparision.Robh3606 said:"Fast CSD is generally based on overall driver design skills rather than just the diaphragm."
Hello Soongsc
The idea was to look for any obvious break-up differences between the Aluminum vs Be diaphrams in the waterfalls or impulse responses. These two drivers are identical except for the diaphram material. So all other variables are accounted for. I thought you were looking for data to see differences between other commonly used materials and Be.
" So it would not seem to make sense to compare different driver categories."
I don't see the logic in that. If it's a "better material" it should be better in either application.
Rob
From the openly available data, I have shown ScanSpeak Be tweeter driver data that shows no significant advantage over other metal. What could we say to that? Is Scanspeak driver correct? Or are they in the same situation as Usher? I'm sure I will see someone putting in nice words for ScanSpeak rather than bashing.
mowry said:
Search on www.google.com the key words "usher audio D'Appolito"
Most of the references are without Dr. Joe's approval; this is very bad. Can you see Usher's standards here?
Originally Posted by stracht at
http://techtalk.parts-express.com/showthread.php?t=211525&page=7
This guy is a class act. The reason he's so ticked at Usher is because they wouldn't give him the time of day...or, IMHO, he's jealous as heck of Joe D'Appolito...he keeps randomly dropping references to Joe's association to Usher in other blogs.
.....
Rant over...I couldn't resist telling our side of the story! The down side is I just gave Mowry more of what he wants (needs) Poor fellow.
Stan Tracht VP
MusikMatters, Inc.
http://www.musicmatters.com/
That's a VP of Usher Audio. Dr. Joe doesn't want to know this guy. Can you see Usher's standards?
http://techtalk.parts-express.com/showthread.php?t=211525&page=7
This guy is a class act. The reason he's so ticked at Usher is because they wouldn't give him the time of day...or, IMHO, he's jealous as heck of Joe D'Appolito...he keeps randomly dropping references to Joe's association to Usher in other blogs.
.....
Rant over...I couldn't resist telling our side of the story! The down side is I just gave Mowry more of what he wants (needs) Poor fellow.
Stan Tracht VP
MusikMatters, Inc.
http://www.musicmatters.com/
That's a VP of Usher Audio. Dr. Joe doesn't want to know this guy. Can you see Usher's standards?
OK this thread is out of control.
ScottG said:
The HM130ZO drivers that I picked up from ebay for £5 each
D) had been previously modified by the owner. In hifi world they produced a few designs around Audax drivers, some with aerogel. Here they said that you could reduce the resonance of the cone by sticking little self adhesive door sealing strips to the cone. When I purchased the drivers they had been modified in that way, except when they were sold, the owner had pulled the strips off and the drivers were described as slightly 'damaged' goods.
Now the relevant point from all of this is that the sticky substance on the cones surface had literally been pulled off the cone, such that the revealed surface, although smoother, largely resembles the backside of the cone. The other point is that this sticky substance can 'easily' be pealed away from the cone if one were to do so. From my perspective it looks as if its been applied to the cone, rather then being a part of it.
The aerogel cones of later years have smooth surfaces too. My HM210Z12s and AP130Z0s both have a non sticky surface. I just assumed the coating they decided to use was changed somewhere along the line. In fact the HM100Z0s I have, also have a non sticky coating, even though they are from vastly different batches, making them unusable as a pair.
What about sandwich composite cones with a structural foam core?
They can damp well and they bend differently. If designed right, they can distribute bending throughout more of the surface than a single laminate cone.
The problem here is who uses sandwich composite cones. Focal does but they use glass fiber and resin. There are better skin materials. For a molded sandwich cone, there is Kevlar (aramid fiber) and resin or there is carbon fiber and resin.
Parts from F1 cars are made with aramid and resin and hard foam sandwich composite material.
The trade-offs include added mass relative to single laminate cones, costly, temperature limitations, and availability.
An added benefit, is that sound pressure transmission loss through the cone from inside the enclosue is high.
Just my 0.02's.
They can damp well and they bend differently. If designed right, they can distribute bending throughout more of the surface than a single laminate cone.
The problem here is who uses sandwich composite cones. Focal does but they use glass fiber and resin. There are better skin materials. For a molded sandwich cone, there is Kevlar (aramid fiber) and resin or there is carbon fiber and resin.
Parts from F1 cars are made with aramid and resin and hard foam sandwich composite material.
The trade-offs include added mass relative to single laminate cones, costly, temperature limitations, and availability.
An added benefit, is that sound pressure transmission loss through the cone from inside the enclosue is high.
Just my 0.02's.
off topic
Most will use either aluminium or nomex for the core.
Some will keep their composite construction secret.
I have used foam as the core.
It has neither the strength nor the stiffness to meet high performance standards.
But, it's easy to shape and cheap. Can't use polyester resin, must be epoxy.
very few if any F1 constructors will use foam in the composite.mowry said:
Most will use either aluminium or nomex for the core.
Some will keep their composite construction secret.
I have used foam as the core.
It has neither the strength nor the stiffness to meet high performance standards.
But, it's easy to shape and cheap. Can't use polyester resin, must be epoxy.
The Hexacone is interesting but different than Focal's sandwich composite. Focal's W cone is more like the TEPEX cone I wrote about.
http://www.multimediamanufacturer.com/articles/mowry307.pdf
I use similar cones in my STEALLUS and STEALLUS X transducers.
http://www.multimediamanufacturer.com/articles/mowry307.pdf
I use similar cones in my STEALLUS and STEALLUS X transducers.
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