ZAKO Posted August 8, 2003 Share Posted August 8, 2003 John Warren I notice the finish on your JBL 2404 tweeters are different than mine. Yours has a orange peel type finish on the baby cheeks. Mine an early mod (1992) has a smooth slate type finish. I wonder if yours scatters the ultra high frequencies better. Interesting in the details but probably sound the same. ITs also interesting that in the JBL K2 the ultra high tweeter horn resembles early T35 & is turned horizontel like Klipsch does. But whats inside the K2 tweeter extends it out to 35K. Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 8, 2003 Share Posted August 8, 2003 Maron- The surface is textured on these (unlike the earlier versions). Maybe it hides surface flaws associated with molding. The wavelength of a 20kHz frequency is around .60" or a little more than 1/2". To interact with the highest frequencies, the "bumps" in the texture have to be around that size, they aren't, they're on the order of a few thousands in size, too small to be *seen* by even the highest frequencies. Q- I just didn't have the heart to tell you (and yes, I did notice the orientation in your earlier photos). Besides the coverage between the two positions is *essentially* identical. Consider that it is a 100° X 100° horn. Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 9, 2003 Share Posted August 9, 2003 The Beyma is a 100 x 60 horn so getting the orientation right makes a big difference in coverage. I played with this tweeter when they were first introduced into the US. Note that, like the T35, the Beyma uses a steel plate keeper which means asymmetric flux density in the coil and stray magnetic field. When plate is rolled from billet, the rolling process drives a crystallographic texture into the sheet. The texture is in the plane of the sheet. Magnetic lines follow the texture and the result is a magnetic field at the gap that isn't symmetrical about the axis of the coil. The manufacturers attempt to *recrystallize* the structure by high temperature heat treating but this doesn't do a complete job (what ends up is something called a "recrystallization texture"). The result is an asymmetric magnetic field which means a jagged frequency response. Magnetic lines are sensitive to slight variances in texture. Ideally the keeper should be *isotropic* (no texture) OR axially textured such that the texture is in the axis of the horn and radially symetrical (as in a billet texture). This is what the 2404H brings to the table. The keeper is cast and then heat-treated to fully recrystallize thus rendering an isotropic structure. To overcome the problems of the T35 and its *cheap* motor, PWK measured the response of each unit and culled those he didn't like. According to PWK himself, he was returning more than half of the units shipped from Cecil St. Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 9, 2003 Share Posted August 9, 2003 Jammin' Jersey has some 2404H for $175 each right now (used of course). That would make a pair pretty cheap. I certainly appreciate how Klipsch has made speakers that sound as good as they do with the components they use. If you upgrade everything, you go broke, even if it does sound better! Marvel Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 9, 2003 Share Posted August 9, 2003 ---------------- On 8/9/2003 10:52:24 AM Marvel wrote: Jammin' Jersey has some 2404H for $175 each right now (used of course). That would make a pair pretty cheap. I certainly appreciate how Klipsch has made speakers that sound as good as they do with the components they use. If you upgrade everything, you go broke, even if it does sound better! Marvel ---------------- These tweeters are have a reputation for being punished. The cost of a pair of replacement diaphragms should be in mind when buying used ones. The diaphragms are about $220/pair. I agree that upgrades can be expensive, that's why you have to be selective at what you swap out. You do not want to have to *convince* yourself that you made a difference when you spend your cash. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted August 9, 2003 Share Posted August 9, 2003 Marvel, I keep saying that the Klipschorn is worth every penny of the $6,000.00 selling price. But, there are some of us that can't leave well enought alone. I'm just surprised that Paul didn't have a tweaked out pair for his own use. John, Don't start pulling your punches now. That is one reason that I enjoy your post so much. Your not afraid to tell it like it is. I decided to build new tops anyway, the ones that I'm using for the 311 horns were really designed for the 805B horns. Last weekend I cut out parts for my new design and this weekend I shelved them. Last night I decided not to use grill cloth to cover them, so I'm cutting new parts again today. It's a lot of plunge router work to follow the shape of the horn. I'll send you a couple of pictures one of these days. Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 15, 2003 Share Posted August 15, 2003 Here's a couple of pics of very early T35 Super Sonax prior to the design change of the horn. Notice the aluminum casting showing signs of pitting corrosion (where there is pitting, cracks are soon to follow, note). The pictures came of ebay. Quote Link to comment Share on other sites More sharing options...
cwm Posted August 22, 2003 Share Posted August 22, 2003 "According to the EV literature (ref. brochure 53157) the T35 is +/-2dB from 3.5 to 18kHz, 3 dB down at 20kHz and a mere 8dB down at 40kHz! The rest of the world seems to measure 5dB down at 15kHz and essentially nothing above that. So much for manufacturers specs" This begs the question as to why they would publish such an exaggerated spec for these units? With other objective potential testers out there you'd think they would err on the side of caution and use a conservative/honest measurement!! It still seems to be an "honest" tweeter though as used in the Heritage series, albeit it a bit lacking on the extreme top........ Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 22, 2003 Share Posted August 22, 2003 ---------------- On 8/22/2003 6:58:26 PM cwm wrote: This begs the question as to why they would publish such an exaggerated spec for these units? With other objective potential testers out there you'd think they would err on the side of caution and use a conservative/honest measurement!! It still seems to be an "honest" tweeter though as used in the Heritage series, albeit it a bit lacking on the extreme top........ ---------------- It's called "lying to sell products". It's nothing new, the audio industry was rampant with it then and is no different today. Who is going to prove them wrong?? What is the regulating agency? Is the customer going to take an anechoic response measurement? Why do you think the industry sells $500 copper wire *cables*? Because they can, no one will challenge the claims. Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 24, 2003 Share Posted August 24, 2003 ---------------- On 8/22/2003 7:05:12 PM John Warren wrote: ---------------- On 8/22/2003 6:58:26 PM cwm wrote: It still seems to be an "honest" tweeter though as used in the Heritage series, albeit it a bit lacking on the extreme top........ ---------------- The problem with the T35 isn't the fact that it only goes to 15kHz. The real problem with the T35 is that it is easily driven into distortion. It was a great tweeter when amps were putting out 5W. It cannot be pushed and when it is, it's a mad dash to the volume pot (-entiometer). Quote Link to comment Share on other sites More sharing options...
ZAKO Posted August 25, 2003 Share Posted August 25, 2003 Ive been saying that for the last 30yrs The T35 & K77 should have been dumped years ago. Quote Link to comment Share on other sites More sharing options...
johnnyp Posted August 25, 2003 Share Posted August 25, 2003 John Warren: I totally agree with your assessment of the T-35. It sounds decent until one turns up the volume, then it starts spitting. Do you use the JBL 2404H as an upgrade to the T-35 in any of the Klipschorns you fabricate? Do you mount them above the squawker or laterally? I think you use an upgraded A-A crossover. Do the JBLs' work without crossover modification? Are there any other tweeter alternatives? Quote Link to comment Share on other sites More sharing options...
John Warren Posted August 26, 2003 Share Posted August 26, 2003 John- The easiest way to integrate it into a Klipschorn/LaScala/Belle is to disconnect the T35 and just leave it alone. Mount the 2404H on a support stand fabricated from plywood. You can use the stock network but you will need to add a resistor L-pad because the 2404H will be too loud. I ignore the stock network all together and just solder up a "duplicate" of the tweeter section (usually 2 caps and a choke) and mount that to the base of the support stand. I then run the amp to the tweeter directly. Padding about 1.5dB is necessary. This is accomplished by adding a 1.5 Ohm resistor in series and a 35 Ohm resistor in parallel with the tweeter. Alternatively, get a variable L-pad and play with the settings until you like what you hear and then just measure the resistance across each leg and then duplicate it using resistors. I am building a pair of add-ons now for a friend with a pair of Khorns, when they are complete I will post some pics to give you an idea of how I do it. The stock Klipsch networks cut the tweeter in around 6kHz. With the JBL unit you can reduce the crossover to 4kHz using a 3rd order slope. This is the optimum cut-off frequency. Concurrent with that, the mid should be cut out a 4kHz also. The added componets for this mod depend on the network you are using. If you are using the AA, I can tell you how to do it. The advantage here is that the 2404H does a better job between 4-6kHz than the k55X does. Alternatives? I've tried the Beyma CP, its ok but if your going to go to the trouble and live with this for the next 20 years, I'd go the extra distance and get a pair of JBLs. If you buy new tweeters + components for the tweeter filters you are looking at $700 + the labor to fabricate the supports. This is a damn good mod for the Klipschorn. Quote Link to comment Share on other sites More sharing options...
johnnyp Posted August 26, 2003 Share Posted August 26, 2003 Thanks for all the info, John. I look forward to some photos when you can make them available. -jp Quote Link to comment Share on other sites More sharing options...
digjr Posted August 27, 2003 Share Posted August 27, 2003 Is this one of the ST-350's in question? I have two pairs of these along with a bunch of K-77's and T-35's. I also think the ST-350's are more efficient and I think they sound at least as good as the K-77's if not a little better. I'll put it this way, without knowing which supposed to be better I saved a pair of the ST-350's (after hearing them) for my own use as opposed to putting them in a pair of speakers to sell. The other set has push-on connectors instead of the spring loaded type. Don Quote Link to comment Share on other sites More sharing options...
djk Posted August 28, 2003 Share Posted August 28, 2003 "Is this one of the ST-350's in question?" The ST350B had two stacked 10oz rectangle mud magnets. Hope you have the phase plug that fits into the horn. "I also think the ST-350's are more efficient and I think they sound at least as good as the K-77's if not a little better." They are much hotter below 8Khz because of the larger horn and bigger magnet. "The other set has push-on connectors instead of the spring loaded type." I'd be interested in measuring the stacked magnet structure with the K77 horn attached, see if it goes any higher than the single magnet model. Quote Link to comment Share on other sites More sharing options...
digjr Posted August 29, 2003 Share Posted August 29, 2003 I do have the phase plug. It would be interesting to see how the K-77 horn would sound on the double stack. I don't have a good way to measure the response but I will mount one and see if I can hear the difference. Don Quote Link to comment Share on other sites More sharing options...
ka7niq Posted July 4, 2010 Share Posted July 4, 2010 Is this one of the ST-350's in question? I have two pairs of these along with a bunch of K-77's and T-35's. I also think the ST-350's are more efficient and I think they sound at least as good as the K-77's if not a little better. I'll put it this way, without knowing which supposed to be better I saved a pair of the ST-350's (after hearing them) for my own use as opposed to putting them in a pair of speakers to sell. The other set has push-on connectors instead of the spring loaded type.Don The tweeters in my EV Sentry III's look like this, as far as the Horn goes, but the single magnet is round, and the terminals appear to be non existant, with black and red wires looking like they come right off the diapraghm terminals, but I have yet to pull off the horn to see. Quote Link to comment Share on other sites More sharing options...
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