WOW !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
which amp do you prefer ?
WOW !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
which amp do you prefer ?
i guess in combination with such startling and revolutionary design breakthroughs such as using not simply wood, but knot-free, wood for a horn, a us patent was inevitableOriginally Posted by linear
you have to wonder who they have working at the patent office.
One of the main reasons for undertaking this speaker project was that the wood turning and cabinet building tasks were a pleasant diversion from my 36 year electronics engineering career as a linear analog circiut designer. I have specialized in zero global feedback/local feedback configurations, in an attempt to make solid state circuits sound more like tubes.
Therefore, almost all of my electronics is custom built. This includes my active crossover (previously described), and my power amps, which are a local feedback, fully complementary bipolar design. They can output 300 watts into 4 ohms (the two 15HM LF drivers), or 150 watts into 8 ohms (the DE 500 HF transducer). Since the speaker system is very efficient (98 dB), this equipment will produce an SPL level of almost 120 dB in my living room. (This is more than adequate, according to my wife!)
My system presently uses a Wadia 861 CD player (www.wadia.com) driving my custom crossover and power amps. There is no preamp or other equalization used. (I also have a Revox reel to reel and a Thorens turntable with Stax cartridge, now seldom used.)
Although I did not build the 861, I did design and patent the analog circuitry of this player, and licensed it to Wadia. They call it their "swift current" block. If anyone's interested they can check this out by entering my patent 4983930 into www.pat2pdf.org or by seeking out my AES paper on this topic.
Linear
Guiseppe's patent may be trivial, but a least the concept works and it protects his business interests. If you want to see the "outer limits" of what can be patented, look at 6025810 in www.pat2pdf.org. The inventor simply claims that he is "sending the signal faster than light" due to the fact that his design "pokes a small hole into another dimension". (This is NOT a joke! Check it out.)i guess in combination with such startling and revolutionary design breakthroughs such as using not simply wood, but knot-free, wood for a horn, a us patent was inevitable
you have to wonder who they have working at the patent office.
Linear
Giuseppe also appears to believe that horn loaded loudspeakers alter the speed of sound in air, as quoted from the patent pdf: "Conventional horn transducers offer, if compared to dome type transducers, the fundamental characteristic of projecting the sound with greater speed through the air..."
Either something was lost in the translation from Italian to English, or maybe Giuseppe is tapping into another dimension as well.
By the way, the listening tests performed by Keith Holland confirmed that in blind listening tests of various commercial horns, the material, wood, metal, fibreglass, etc was not correlateable with perceived quality. Knotty or not!
Jack Bouska
You got to love multi-dimensional audio... maybe there is a new patent waiting to be had for speaker wire too.
Widget
Excellent job! I'd love to build a similar pair of round horn/waveguides for my system. Can I ask what lathe did you buy for this project? I have been eyeing a wood lathe for my shop and I think the biggest bottleneck seems to be the swing distance over the bed unless the head turns 90º.
I am curious if Dr. Geddes has had any trouble from Zingali with his speakers since he uses a round horn (waveguide) whose mouth is large then its depth.
Obviously something was lost in tanslation and I think you know exactly what the original meaning was.
English is your mother language but believe it or not there are other human beings out there with another mother language.
What additional languages you speak (write) that enable you to discuss complicated physical coherences in a forum like this?
Me 1, you?
Ok, I know english humor and I know that I as a German can't understand it..... I was told that in England BTW. Nevertheless I always had a good time in England
I appreciate your stunning speaker work! Your a hifi-maniac
It has already been suggested (in fun!) that I should have posted this project on the "Usher Heritage Forum". So, at the risk of being banished to the "Wood Turning Heritage Forum", or even the "Audio Patents Heritage Forum", I will try to answer your questions.
Lathes that cost less than thousands of dollars seem to have a max swing over the bed of 14". Obviously, this is inadequate for turning a 15.5" horn. What I did was buy the cheapest lathe available from HarborFreight Tools (http://www.harborfreight.com/cpi/cta...emnumber=45276) for $135 and modify it. In this case, the "cheapness" is an advantage, because the bed is just two square steel tubes bolted to the frame. (Quality lathes have a one-piece cast body and bed.) Thefefore, it is relatively easy to drop the bed by using 1'' "spacers". This gives a 16" swing. For the spacers, I used rectangular aluminum tube (part # 88935k551 from www.mcmaster.com). Yes, this lathe is a piece of junk, but it did the job!
Regarding the Zingali patent, I will make some comments, but note that I am NOT a patent attorney. However, I have consulted in this field as a technical advisor and expert witness, so I know more than a little about the system. In my opinion, the Zingali patent is very weak (big surprise!), as there is almost certainly prior art published that discloses a round horn whose mouth diameter is larger than it's depth. However, since this patent has been granted, it is assumed to be valid, so the onus would be on defendent, in an action brought by Zingali, to prove in Federal court that this prior art exists and is relevant. Does Dr. Geddes even know about Zingali's patent? Perhaps not. Does Zingali know about the details about the Summa speaker? Probably not. If did did know, he would first send a "cease and desist" letter, but might not follow up with legal action. It might be too risky financially to try to enforce a "weak" patent in the courts.
In any case, what is relevant to JBL Heritage Forum Members is that it is generally accepted that one may make use the teachings of a patent for private research and construction, so long as there is no commercial use or financial gain involved. So, buy a cheap lathe, turn a horn, and (preferably) mount a JBL driver on it!
Linear
Inexpensive Chinese manufactured wood lathes are adequate for amateur bowl turning, or axially symmetric round mouth horns/waveguides. The machine I have can turn up to 10” on the bed side, and has provision (thread) on the outboard side for larger pieces. The user must build a tool rest for outboard turning. It is important to choose a machine that has variable speed, because large diameter turning requires slow speed (800-400rpm). Softwood or green wood is also recommended, to limit the torque generated during turning.
Any oblate spheroid waveguide with an exit angle of +/- 45deg or less will have a width to depth profile which will not be in violation of the Zingali patent.
Jack Bouska
No, I’m not ashamed to say that I truly don’t know what the original meaning was. (and not for lack of trying to understand)
I read that paragraph in the patent several times, and could not understand what Zingali was talking about. As far as I know, horn loaded transducers do not alter the speed of sound in air. The speed of sound is a constant (depending slightly on temperature), and even the net displacement of molecules within the compression chamber and phase plug will not alter the apparent speed of sound, but rather just cause a slight Doppler frequency shift (undetectable unless at max volume).
So what do you think Zingali meant by his statement: "Conventional horn transducers offer, if compared to dome type transducers, the fundamental characteristic of projecting the sound with greater speed through the air..."?
Even in the original Italian, I believe he has just written nonsense (but feel free to correct me).
While Zingali may have built a good device, the written evidence he has included in the patent is not physically meaningful support for his claim. (eg knot free wood, depth to width profile, etc). Zingali may be a good inventor, but based on the translated patent, he is probably not a good physicist.
Zingali did not post on this forum, so it’s somewhat unfair of me to poke fun at his patent, but on the other hand, he did expose himself to some level of ridicule by making such physically indefensible claims.
As far as other languages go, as you can tell, I’m still struggling with English!
Seriously, I have been studying Spanish, but I would not be so brash as to post on a Spanish language HiFi forum unless I felt I was proficient enough to be understood, and that I had information valuable enough to share.
Guido, I understand your posts quite clearly, and I value what you write, so you’re contributions are clearly very good examples of ESL involvement in this forum.
Jack Bouska
I expect they are suggesting that horn drivers offer better transient response... they are just being colorful.
I doubt they are suggesting that they have developed a "sonic accelerator".
Widget
OK Jack 1:1
I think the patent refers to the changes in air pressure at the border from compression chamber to horn.
Great thread!
The 'faster than light antenna' is hilarious!
Did you also see the note in the patent that 'accelerated plant growth' has been observed by the inventor and witnesses?!!
The reason, quite clearly, is that 'energy from another dimension influences plant growth'!
Awesome stuff!
I you find any more gems like this one, please pass them along!
Cheers, Ralph
OK, you asked for it! But just one more patent and then it's back to topic!Great thread!
The 'faster than light antenna' is hilarious!
Did you also see the note in the patent that 'accelerated plant growth' has been observed by the inventor and witnesses?!!
The reason, quite clearly, is that 'energy from another dimension influences plant growth'!
Awesome stuff!
I you find any more gems like this one, please pass them along!
Cheers, Ralph
Try 4320756 in www.pat2pdf.org
Linear
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