D-MAN Posted March 8, 2006 Share Posted March 8, 2006 Here's the 1956 Cobra-flex patent to Levy (US # 2746558) You need to have the TIF viewer installed to look at the image on the USPTO website, but here's the link: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=2746558.WKU.&OS=PN/2746558&RS=PN/2746558 Also attached is first drawing. DM Quote Link to comment Share on other sites More sharing options...
sunnysal Posted March 8, 2006 Share Posted March 8, 2006 I always thought those kind of bends in the mids and highs were verboten, but this seems to be a widely acclaimed horn...dubai is using on top of his khorns with 2404Hs above...tony Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 8, 2006 Author Share Posted March 8, 2006 Haven't heard one, but I know that Armando has them, too. They do have a good reputation. DM Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 8, 2006 Share Posted March 8, 2006 Internal view of the cobreflex. An assembled unit has a stiff cardboard piece that splits the path of the section close to the throat, (i.e. a center divider). A rubber gasket separates the top and bottom half to prevent metal-to-metal-contact. Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 8, 2006 Share Posted March 8, 2006 The exterior, after sandblasting. They really look nice unpainted. And they sound real good. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 8, 2006 Author Share Posted March 8, 2006 Just looking at them, there are 3 different expansion rates involved. Such a long overall pathway would tend to support the fact that they can smoothly go down rather low (say what, 250Hz?), I would guess. DM Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 8, 2006 Share Posted March 8, 2006 Yes, you're right. The specs from hifilit.com say it's good down to 250. D, I tried the website but I don't have a tiff viewer. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 8, 2006 Author Share Posted March 8, 2006 You have to download the TIF viewer from the USPTO website in order to view the images (its free). Don't tell me you want me to convert them to .jpg's and upload them! That is a lot of work (which is why they are not already here)![] DM Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 8, 2006 Share Posted March 8, 2006 Ok, I'll try that, tnx. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 8, 2006 Author Share Posted March 8, 2006 Here is the "AlternaTIF" product for Explorer. http://www.alternatiff.com/distribution/alternatiffx-1_7_6.zip Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 8, 2006 Share Posted March 8, 2006 I got it installed. Great pictures. I'll go back to that website. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 8, 2006 Author Share Posted March 8, 2006 Armando, next time you're there, so you can see the pics good this time:[] http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220050276431%22.PGNR.&OS=DN/20050276431&RS=DN/20050276431 DM Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 9, 2006 Share Posted March 9, 2006 It sure looks good! Quote Link to comment Share on other sites More sharing options...
boom3 Posted March 9, 2006 Share Posted March 9, 2006 In one of Paul's papers on FM distortion, he measured the Cobraflex and the results weren't good. He said the folding scheme was "violent reflexing". Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 9, 2006 Author Share Posted March 9, 2006 Some food for thought - did you ever read a PWK paper or DFH where he tested and said something good about someone else's product? I get a particular kick out of the often reported "doesn't go below 70Hz", which he seemed to apply to every competitive product. What would you expect? DM Quote Link to comment Share on other sites More sharing options...
boom3 Posted March 9, 2006 Share Posted March 9, 2006 Some food for thought - did you ever read a PWK paper or DFH where he tested and said something good about someone else's product? I get a particular kick out of the often reported "doesn't go below 70Hz", which he seemed to apply to every competitive product. What would you expect? DM True enough...but the folding scheme is more 'violent' than was/is acceptable, before or since for a 'hi-fi' MF reproducer. This and that wacky mailing-tube folded midrange in the EV Patrician were not successful, otherwise we'd see their progeny all around us. The consensus of mature engineering thought is that folding is unacceptable for MF and HF horns for 'hi-fi'work. I saw a lot of time and money being poured into old technological dead-ends like this when I was a subscriber to Speaker Builder. Quote Link to comment Share on other sites More sharing options...
ajsons Posted March 9, 2006 Share Posted March 9, 2006 Boom3,Maybe you should give the cobreflex a listen, and not at the airport.. I actually prefer it over my EV SM120 and 511B, using the same driver.About 3 years ago, there was a thread called Installing Mike's 511B, where a couple of forum members did listening tests on the cobreflex, 511b and the K-400 horn. The cobreflex was the first choice and the K-400 the dead-end. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 9, 2006 Author Share Posted March 9, 2006 If I remember correctly Maron uses a Cobraflex, too. DM Quote Link to comment Share on other sites More sharing options...
sunnysal Posted March 9, 2006 Share Posted March 9, 2006 I am not sure if too much is made of the bending/folding causing audible problems. the graphs and people's listening tests seem to say "NICE"... I remember similar issues with the Jubileee...while PWK may have been critical of the cobraflex for its bends he also claimed one of the benefits of the jubilee was that it had fairly flat extension all the way up to 1,200hz, way higher than common wisdom says you should cross over a bass bin...I think dean commented that though the jubilee can go up that high he would never cross over that high since it would surely sound bad (forgive the loosely remembered quote from dean if somewhat inaccurate). I on the other hand assumed it should sound fairly good that high up just as I assume the cobraflex sounds pretty good throughout its range since frequency response and listening tests seem to confirm...oh never mind... tony Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 9, 2006 Author Share Posted March 9, 2006 What Tony said. The CobraFlex was last made by EV in 2004 (last reference I could find).My guess is that it sounds fine inside of its bandwidth.DM Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.