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A recommendation: "House of Flying Daggers", now available from Netflix. Even if the genre leaves you cold,the gorgeous photography and wide-band sound will thrill you. If you like "Crouching Tiger..." or "Hero" you will probably love this movie. The sound ranges from the high tinkle of glass chimes to the thud of large drums. In common with the two movies just mentioned, the plot goes in many directions before getting to anything like what Western sensibilities would consider a conclusion. Here's the IMDB reference: http://www.imdb.com/title/tt0385004/

14 gage low-voltage lighting wire about $35/250 feet at Home Depot.

Yes I heard those. A cousin had a system with those tweeters and I think 8 inch woofers. I recall (from a very limited audition) that they seemed very clear and sweet, if you got about 8 feet or more away. I don't know what happened to the company. I recall some discussion that the glass plate acted like a transmission line for the piezoelectric driver glued to the back. Paul used 'Major Breakthrough' along with 'O. Gadfly Hurtz' as noms de plume when he lampooned the 'next big things' throughout his long career. One could make a sizable web page on discarded driver designs of the past.

---------------- On 4/22/2005 1:32:48 PM DRBILL wrote: That guy has a rude awakening when he visits the patent office. It was done c. 1974-5. (snip) ---------------- I would agree since I have witnessed this technology demonstrated by an entirely unrelated company. However, the patent office has granted any number of acoustic patents that either duplicate earlier work or are very minor tweaks thereof. Apparently, whoever the examiner is for that class of patents either does not understand the prinicples involved or does not bother to look too closely at prior art.

Thnaks for posting this, its certainly an interesting look at the subject. One minor caveat: the author states that modern domes are designed for omnidirectional radiation. He's been reading too much ad copy. True omnidirectional radiation is into spherical space, i.e the pulsating sphere that so many speaker 'designers' have vainly pursued. The other misunderstanding is that many people assume domes have wider radiation patterns than a cone or flat diaphram of the same size. Taint so. Allison, among others, proved this 30+ years ago, and Olson years before that. It's the size, not the shape, that determines what radiation pattern a _circular_ diaphram will have. The virtue of domes is that their breakup nodes are smoother and different than cone-and-dome radiators. Give me a well-designed horn though. I've been the dome mid and tweeter route and I have returned unto the ways of the True Faith.

I have the Scott 333B from around 1963-1964. It delivers beautiful FM stereo. One of the AM antenna coils has a short so the AM does not work well, alas.

I have a Makita 10 inch table saw. Among the other lawyer-installed features, it has a "riving knife" between the anti-kick back pawls. This trio is behind the blade and the riving knife holds the cut open after it passes the blade. I thought it was silly but it really does seem to hold the cut open pretty well. It may be possible to retrofit a riving knife on to an existing saw. I second the comments about calibration. If I am doing anything of precision, I re-level and resquare the saw (it's on a base with wheels on two legs).

What is interesting is watching Indian, Chinese, Mexican or other 'adaptations' of American movies, often using the same titles and stealing footage from the original films. The main characters are always the nationality producing the rip-off, of course, for local consumption. Some of these are hilarious and some are pathetic. All are copyright violations out the wazoo!

What is interesting is watching Indian, Chinese, Mexican or other 'adaptations' of American movies, often using the same titles and stealing footage from the original films. The main characters are always the nationality producing the rip-off, of course, for local consumption. Some of these are hilarious and some are pathetic. All are copyright violations out the wazoo!

We used Hardi-Backer, which is 1/4 inch thickness. It's pre-gridded, all the we did was score with a hooked tile knife and snapped. Then we sanded the edges. We are going to use Liquid Nails to put it in place as a back splash covered with decorative vitreous tile.

Depending on condition, Corns have been going for 700-900 a pair lately. Shipping-properly packed-will run you another 150-250- within contiental U.S.

why do you want to replace the K52s? There is a set of K55/K600 on e-bay right now, item #5766037315

Thanks again Gill. The tone of the review sounds British, is that the provenance? Also I notice he was using it with a full-range driver and did not mention the possibility of adding a K-1000 and whatever tweeter (University 4401 maybe).

---------------- On 4/7/2005 7:03:12 PM j-malotky wrote: Out of curiosity, as I no nothing about porting, does the position matter in the cabinet? Could it be in the middle of the cabinet insted of the botom? Reason I ask is I see tube ports placed any which way in speaker cabinets. If you would build the CornW cabinet say skinier and taller for example, if you kept the internal cabinet air mass identicle to the CornW, and the port air space dimentions exactly the same, would it work the same? On the same note, could you put in 4 or 5 tube ports that equaled the same air mass of the CornW port? Just wondering??? JM ---------------- The volume of the air mass must be the same for the tuning to 'work', however, there is an minimum acceptable port diameter. Ports that are too small cause the air stream to increase in velocity and cause an audible 'chuffing' sound at high speaker excursions. Also, ports that are very small can actually whistle although this is also a factor at high excursions. The generally accepted minimum port diameter, for a tube-type port, is 2 inches and 3 inches or more is desirable. The ports must not be seperated far enough to be one-half wavelength apart at any frequency within the woofers range (this also includes an octave above nominal crossover) I once built a large vented enclsoure with two woofers and two ports equidistant from the woofer pair. I wondered why I had a very audible dip at 120 Hz. It was due to the interference betwen the widely spaced ports. I plugged one up and adjusted the tube length and the response flattend out. The port shelf of the Cornwall serves to brace the cabinet as well as port the back side of the woofer. Paul proved and refined this over many years. If you want to build a Corn-clone, stick to the master's design.

Alnico was developed in the 30s and 40s because the permanent magnet motors of the time tended to be heavy for their power. Permanent magnet DC motors were needed for aircraft and the existing iron-based magnets were simply too heavy and inefficient. Alnico, until the developmenmt of so-called rare-earth magnets (samarium and neodyium)had the greatest magnetic power for a given size. In the early 1960s, civil strife in what was then called the Belgian Congo (later Zaire, now the Congo again) disrupted the Western supply of cobalt, which is also used to make steel alloys vital for many products. The price of cobalt steadily climbed until the mid-70s when many speaker manufacturers switched to ceramic ('mud') magnets, and then the rare-earth magnets evolved in the late 70s and early 80s. Shielding of a magnetic circuit can either be accomplished by a counter (bucking) magnet, or by an iron enclosure. Since ceramic magnets are literally dirt cheap, it is more economical to glue a bucking magnet on the back, and voila, it is "shielded"-not totally, but good enough for home theater. Many people believe that speakers using alnico magnets exhibit lower distortion than those using ceramic magnets. That may have been true of the early designs, but with better computer visulaization of the magnetic circuit and use of rare-earth magnets, I believe the alnico "advantage' has disappeared. In any case, the choice of a loudspeaker/driver is a disciplined, balanced one and today, the type of magnet material is really not one of the more important factors to consider.

Loudon Wainwright III was the singer of "Dead Skunk In The Middle of The Road."

http://www.nywf64.com/hougt07.shtml the entire site is interesting. The Altec system, pictured here with People Who Wear Hats and Jackie Kennedy Suits, was installed in one of the Homes of Good Taste constructed at the fair.

Thanks for the picture. I lived on the post from 59-61.

How does one DC couple tubes to speakers without B+ (anywhere from 250 volts on up) appearing at the speaker terminals? It sounds like this is a take on the Circulotron OTL design. "Thermoionic" is the generic term for emission of electrons from a hot cathode, so I'm amused to see the ad copy gushing over it. Kind of like Ford bragging that their cars are powered by Otto cycle internal combustion engines.

These are Dahlquist DQ-10s, not Quads, although the resemblence was not coincidental. I have a pair of DQ-10s in my second second in my study.

There are the variables of cabinet condition, of course, but most Cornwall pairs are going for around $900 now, not including shipping. This is my experience in buying two pair recently (one e-bay, one privately) and watching ebay prices for other sets.

Firefox

Moon, save yerself some grief. I usually agree with Bob but I would put a 10 uF cap in series with the positive lead of the K57 prior to any listening. This will not protect as well as a real crossover but it is better than nothing.