tigerwoodKhorns Posted July 13, 2008 Share Posted July 13, 2008 Has anyone compared the JBL 2370, 2380 and 2385 horns to the Altec 511 or Tractrix horns? It looks like the patent has long expired and knockoffs are really cheap: http://www.aftermarketdiaphragms.com/horns.html An adaptor will be needed for a 1" driver but that is not a big deal. This looks like an easy repalcement for a Khorn. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted July 16, 2008 Share Posted July 16, 2008 The 2370 is for a 1" bolt on driver, the other two are for 2" drivers. These horns are generally used for sound reinforcement and are crossed at 1kHz or higher. Probably not good for Khorns. Unless you construct a 200-1600 Hz midrange horn and use the JBLs as tweeters. And listen to the system from about 100 feet away.[^o)] Quote Link to comment Share on other sites More sharing options...
cjgeraci Posted July 16, 2008 Share Posted July 16, 2008 Laidlaw v. Organ, 15 U.S. 178 (1817). Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted July 17, 2008 Author Share Posted July 17, 2008 Carl, So you used them and didn't like them? I was just thinking that there may be tractrix or Altec 511 type horns available new because any patent has long since expired. Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 17, 2008 Share Posted July 17, 2008 According to JBL, the 2370 has full loading to about 630Hz and is usable to 500Hz. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted July 17, 2008 Share Posted July 17, 2008 those are actually pretty good prices. I have been thingking about the larger format JBLs. Quote Link to comment Share on other sites More sharing options...
djk Posted July 18, 2008 Share Posted July 18, 2008 view pdf H-2370 / CAT NO - 4845 • throat diameter: 1" • horn material: ABS with glass filled polycarbonate • coupling pattern: 3 bolt 2" c ...more info PRICE : $ 61.00/ea. view pdf H-2380 / CAT NO - 5378 • throat diameter: 2" • horn material: ABS with glass filled black polycarbonate • coupling pattern: 4 bol ...more info PRICE : $ 63.45/ea. QTY. If you really want them, have Bob Crites (or myself) order them for you, and save you a couple of $$$. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted July 18, 2008 Share Posted July 18, 2008 I tried a 511B in a La Scala for a center channel and liked it. Never compared it or the original with any of the others mentioned. I wonder what PWK's preference had been? Does anyone know about that? I don't plan on changing the original squawker in our Klipschorns; it's responsible for a fairly significant portion of the overall voicing of the loudspeaker. However, I do agree with the idea of being open to different approaches, and the new tweeter Bob C. developed is IMO a worthwhile upgrade. Still, I know of some who find the older K-77s, particularly the alnico version, far more musical. Why try to fix somethin' that 'ain't broke? Erik Quote Link to comment Share on other sites More sharing options...
Don Richard Posted July 18, 2008 Share Posted July 18, 2008 According to JBL, the 2370 has full loading to about 630Hz and is usable to 500Hz. There really aren't any drivers with which one can achieve that performance. JBL's 2426 compression driver is recommended to cross @ 800 Hz minimum, and it's about the best for that horn. Sounds terrible, by the way. Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 18, 2008 Share Posted July 18, 2008 According to JBL, the 2370 has full loading to about 630Hz and is usable to 500Hz. There really aren't any drivers with which one can achieve that performance. JBL's 2426 compression driver is recommended to cross @ 800 Hz minimum, and it's about the best for that horn. Sounds terrible, by the way. Opinions are always welcome. I know the top end of the 2426 drops off rather suddenly.I think we were talking more about changing out the K400/401 horn for the JBL, and the K55 crosses at 400, so there are drivers that will cross low enough. The horn wouldn't quite work, though. Maybe in an LS if you raised the crossover point. The LS can get to 500Hz. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted July 18, 2008 Share Posted July 18, 2008 According to JBL, the 2370 has full loading to about 630Hz and is usable to 500Hz. There really aren't any drivers with which one can achieve that performance. JBL's 2426 compression driver is recommended to cross @ 800 Hz minimum, and it's about the best for that horn. Sounds terrible, by the way. k-69 k-1132 k-1133 a k4m manifold with 4 k-55 drivers on it I only bring this up since I have a pair of each and am thinking about the 2380 series. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted July 19, 2008 Share Posted July 19, 2008 According to JBL, the 2370 has full loading to about 630Hz and is usable to 500Hz. There really aren't any drivers with which one can achieve that performance. JBL's 2426 compression driver is recommended to cross @ 800 Hz minimum, and it's about the best for that horn. Sounds terrible, by the way. Opinions are always welcome. I know the top end of the 2426 drops off rather suddenly.I think we were talking more about changing out the K400/401 horn for the JBL, and the K55 crosses at 400, so there are drivers that will cross low enough. The horn wouldn't quite work, though. Maybe in an LS if you raised the crossover point. The LS can get to 500Hz. These JBL horns are the wrong devices to use in a loudspeaker system as a bandwidth-limited midrange horn. They are designed to be used as the HF in a three-way sound reinforcement system. They are of a bi-radial design and are constant directivity as a result. Any compression driver mounted to them will require top octave compensation, and bottom octave compensation if you try to run these horns too low. The top octave comp allows the reproduction of higher frequencies with even horizontal polars over a greater than 10:1 frequency range, and works out to about 12 dB boost @ 15kHz depending on the driver used. According to JBL info, frequency response @ 500 Hz is -20 dB relative to 1500 Hz. So if you are running 1 watt in the midband of these horns you will need to put 100 watts into the low end of it's range to get flat frequency response. To my knowlege there are no 1" drivers with that capability, and adapting a 2" unit to a 1" throat won't get hi-fi results. I've been through all of this before. I am currently using a Peavey 1" CH-941 CD horn as the HF in my system. It is about the size of the 2" JBL 2380 and is advertised to go down to 500, or 800 Hz, depending on which set of Peavey specs you are looking at. I am using an analog crossover so it is easy to change crossover points and to change from 3 way to 2 way operation. When used as a 2 way, there is next to nothing coming from the Peavey horn at the crossover point. Bottom octave comping the horn causes the limiters that I have set for driver protection to engage, which sounds terrible. You would get similar results from the JBLs. If you want a HF horn for a 2 way system, get a K402 setup. It ain't cheap, it's big, but it will work and sounds good. Using a CD horn for HF in a home system works well in a 3 way setup due to the smooth horizontal polar dispersion but plan on using a midrange to go from the bass crossover frequency up to at least 1 kHz. I'm using the K400-K55 combo for that, crossing to the HF @1200 Hz, and it sounds great. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted July 19, 2008 Share Posted July 19, 2008 "They are designed to be used as the HF in a three-way sound reinforcement system" I have a k-702 with a k-70-g driver as used on the hf section of the 535's. The 535's use a k-502 as a mid driver. I'm having a hard time understanding why a 2380 series JBL horn can't compete with a k-502. JBL claims 400hz min cutoff. Unless your comments are directed to 2370 series horns. I personally do not like the tractrix sound in the lower mid band because of the nature of tractrix in the way they start late and are not strong in the lower end as are other technologies with out elaborate EQ pumping. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted July 19, 2008 Share Posted July 19, 2008 I'm having a hard time understanding why a 2380 series JBL horn can't compete with a k-502. JBL claims 400hz min cutoff. Well, I looked at the uncompensated and compensated response curves on a 2380/2445 combo and 500 HZ is down -26dB relative to midband. That would be 400 watts to achieve flat response when the midband is getting 1 watt. You are putting that power into the driver at the point in it's frequency range where excursion limits come into play. Putting excess low frequency power into a compression driver is an excellent way to blow diaphragms and hear a lot of distortion until that happens. When sizing horns and drivers current engineering practice is to operate the horn at about double it's advertised lower cutoff frequency. For example, the K-55V driver's lowest frequency where it can take full rated power is 250 Hz, it is crossed at 400 Hz and the K-400's lower cutoff is around 230 Hz when mounted on it's baffle board. Quote Link to comment Share on other sites More sharing options...
djk Posted July 19, 2008 Share Posted July 19, 2008 The 2380A has better directivity control at 500hz than an Altec 311-90, it's a function of the mouth size. A horn with good Di at 500hz will need to be at least 30" tall. The JBL2380/2445 is roughly ±3dB from 600hz~7.5Khz with no EQ. I have used it in a two-way with 107dB/2.83V/1M woofer section crossed at 650hz (the titanium did not sound good crossed lower). With passive network EQ it went to 16Khz. I prefer the sound of a three-way. Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 19, 2008 Share Posted July 19, 2008 We use the 2380 at work in a variety of configurations and there is no way I would ever consider using them in a home environment. In fact, if it were my choice, we wouldn't be using them at work either. The 2380 certainly has a very decent coverage pattern and can get real loud with the right drivers, but they are shrill as all get out...or more of a congested shrill sound - it's hard to describe. You know there's something wrong when you can walk into other venues and identify the 2380 after hearing just a few seconds of music. Ideally, you just wanna be hearing the music - not the speakers. I actually ran some curves at work to see if there wasn't anything blaringly wrong in the frequency response, but overall they looked well behaved. When I get back home or find an internet connection for my laptop I can post those curves. I recall them being extremely similar to the curves that JBL posts. The only downside is that it's a system response with some JBL2226H drivers in the mix (so I can't verify the LF extension)...I think we're crossing to them at around 800Hz. Actually, here's the PDF for the 2380:http://www.jblpro.com/pages/pub/components/2380a.pdf I was just noticing they're rated for 10% distortion at 1W and 10W of input power. [] Quote Link to comment Share on other sites More sharing options...
djk Posted July 20, 2008 Share Posted July 20, 2008 Distortion is also the function of the cut-off frequency of the horn, the lower the horn goes, the higher the distortion will be at high frequencies. The 2360 horn has 30% THD with 5W input at 10Khz (for instance) http://www.jblpro.com/pub/technote/tn_v1n08.pdf The newer OA series 1.5" throat horns and drivers have about 10dB less distortion in the 8Khz region. http://www.jblpro.com/pub/technote/tn_v1n21.pdf This is due to a higher cut-off frequency, and opening up the slot in the throat. The narrow slot, long tail throat gives rise to a 'quacking' or 'frying bacon' sound at high volumes. If you think about it, the air has to create a vacum on its rear-wave to go above 162dB (at the diaphragm). This creates a 'clap' similar to a lightning bolt when the air rushes back in, this is the audible 'quack' that can be heard. Keep in mind that most of these large drivers are about 117dB/mW on a terminated tube, or 162dB for 32W input. (the Carver PM1.5 was often seen driving the 2445, it can put out in excess of 350W/16R on program material) The air in the throat simply overloads. PS, I've had the Atlas drivers 'quack' with less than 100W on the wrong type horn. If you want something that doesn't 'quack', and has much lower distortion than any other midrange driver I've heard, look into the Community M200 on the SH494 horn. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted July 20, 2008 Share Posted July 20, 2008 The JBL2380/2445 is roughly ±3dB from 600hz~7.5Khz with no EQ. The info just posted by Dr. Who shows that combo being within 5 dB from 1050 Hz-5000Hz with no compensation. Quote Link to comment Share on other sites More sharing options...
Deang Posted July 20, 2008 Share Posted July 20, 2008 Basically a big arse PD5, it's hard not to like that driver. I get the benefits of the lower compression ratio, but unless you go active and EQ it, it's finished at around 4kHz. Kind of limits tweeter choices unless you're a network whiz (not me:) http://www.loudspeakers.net/files/specs/new/m200.pdf I always found that M4 intriguing -- crossovers at 250 and 2000 using the Community VHF100 for the top. Hard to imagine that not sounding better than pretty good. Have an opinion on that beast? Kind of expensive, but what isn't -- if it's good. It's interesting to compare the distortion plots of the M200 and BMS 4591 (both 2" drivers using non-metallic diaphragms). http://bmspro.com/fileadmin/bms-data/curves_compression/ferrite/bms_4591_curves.jpg Quote Link to comment Share on other sites More sharing options...
Deang Posted July 20, 2008 Share Posted July 20, 2008 Sure, looks like Dennis has a rare miss, but what does it really matter -- once you slide it all into the room you can forget those curves anyway. I think the real point here is simply to avoid the slot type horns. The majority of drivers, regardless of what you choose, deliver admirable peformance -- it's the horn that will make or break the sound. Quote Link to comment Share on other sites More sharing options...
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