Al Klappenberger Posted November 26, 2003 Author Share Posted November 26, 2003 Shawn, "The two way has a more extended top end then the 3 way with the t35." ----------------------- You have hit on a point here. The poor old T-35 always poops out above about 14 KHz. Your Altec 902 goes happily right on up to 20KHz. Remember though that going up that high is only one step. The next step is the dispersion of the horn up that high. With a single large horn the highs will begin to come straight out. I personally belive that a 3 way system using a high quality modern tweeter with a smaller horn than the Altec 511 will perform the dispersion up high much better than the 511 will. I am using Beyma CP25 tweeters in a 3-way system. Here again, an extreme slope crossover will be needed to remove the lobing associated with the squawker / tweeter interaction. Only then will there ne an overall improvement by a 3-way over a good 2-way. This is why I have included a way to use the ES600 network either 2-way or 3-way using an external squawker / tweeter crossover. The combination of the Altec 902 and 511b horn running 2-way with a LaScala or Belle Klipsch woofer is still an awsome sounding speaker! Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted November 26, 2003 Share Posted November 26, 2003 Al, "The next step is the dispersion of the horn up that high. With a single large horn the highs will begin to come straight out. I personally belive that a 3 way system using a high quality modern tweeter with a smaller horn than the Altec 511 will perform the dispersion up high much better than the 511 will." Maybe, but I'm not sure of that yet. There are a few reasons a speaker should have a smooth FR off axis. The first is obviously for off axis listeners to hear a better presentation of the music. The second is more complicated. The sound we hear is a composite of the direct sound from the speaker as well as the reflected sound from the walls/ceiling. As such the composite FR is based both on the direct sound as well as the reflected sound. Having great on-axis response but a major suckout at 1k off axis in a normal listening room is going to screw up the final sound you hear even if you are sitting on axis. The rooms reflection (some of it will be heard as ambiance) is going to have a suckout at 1kHz which won't sound quite right as it won't match the direct sound. This is most noticeable through the bass and mids. Having a more controlled narrowing of the high end isn't as big of an issue as having a very sudden major change in FR off axis like what can occur at a crossover point between one driver that is beaming to another that isn't. A controlled narrowing up high can cause you to loose a little 'sparkle' to some recordings. On more common cone/dome speakers a 1" tweeter dispersion drops as a function of freqency too and they can beam the upper end quite a bit more then some will expect. Some manufacturers (of very good speakers.. for example the $20,000 Revel Salons) add a rear firing ambiance tweeter that usually only runs above 8k or so (and the level is user adjustable) or so to bounce off the front wall to get back some of that 'sparkle' from the narrowing dispersion of the main tweeter. Like I had mentioned to you earlier where these speakers are destined to go listeners are always going to be on axis so the first reason above for having wide dispersion isn't needed. And as far as the second reason this room is going to be extremely dead acoustically. With lots of treatments I'm going to try to stop reflections off the side walls as much as possible in this room. I will be using the ambience in the recording, not the artifical ambience added from the room. So not having a super wide dispersion up at the very top end shouldn't be much of a problem since if it did have a wide dispersion I'd just be absorbing the rooms bounce up there anyway. And it is much easier to stop the rooms influence at higher frequencies then it is at lower ones. I'm certainly keeping the possibility of these ending up being a three way (or possibly even trying the ambience tweeter) open. It is just that in my intended use of these in my room I'm not convinced there will be any benefit from going this route and it would of course add considerable expense.. possibly for no positive gain. Shawn Quote Link to comment Share on other sites More sharing options...
sfogg Posted November 26, 2003 Share Posted November 26, 2003 It should also be mentioned that instead of a very wide smooth off axis frequency response a very tight/narrow well controlled full bandwidth frequency response can also help avoid the problems with the rooms interference and will limit it even further. However achieving this type of pattern over the full range is fairly difficult. A Sound Physics Labs Unity Horn will do it well from 300hz and up. The Legacy Whisper does this nearly full range but its tradeoff is that it needed to be huge to accomplish it. Large dipole speakers (Maggies, MLs and such) tend to influence the room less because of the nulls to their sides. One of the advantages of the K'Horn being in the true corner of the room (as opposed to false corners) is that it is already radiating the bass along the dimensions of the room. Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted November 26, 2003 Author Share Posted November 26, 2003 Shawn, It sounds like you have research what you need and done so quite throughly. The ES600 will allow changes later if you ever decide to try 3-way anyhow. Tinkering is part of the fun you know! Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted November 26, 2003 Share Posted November 26, 2003 Al, "Tinkering is part of the fun you know!" True, it gets pricey though. Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 13, 2003 Author Share Posted December 13, 2003 Guys, As promised, here is the final layout for the new 600 Hz crossover. The 1.0 mHy inductor and associated 51 mFd cap were moved to be exactly on center with the 3.6 mHy inductor which is sitting on top 1 Inch spacers. This reduced the coupling between them to the point where the performance is very close to what the computer predicted. I will be shipping two of them to sfogg in a few days. If anybody decides to duplicate the design I would be very interested in their reaction to it. I will be posting more details on my web site in the near future. Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 13, 2003 Share Posted December 13, 2003 Al, Thanks for the update. Do you think it is worth the effort for me to reposition the components on the one ES600 to duplicate the new layout? I'm definitly looking forward to hearing these in stereo. BTW, the components for the bridge should be arriving monday so I'll try duplicating your tests on the ES600 with my SD380. Thanks, Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 13, 2003 Author Share Posted December 13, 2003 Shawn, No, don't try to update the first one. The difference is very small and all you will do is make it look like a breadboard job! To see the difference I had to overly the two plots and look through them with a strong light. The difference is about 1 dB on the arc top and about 5 Hz on the crossover frequency! If I thought it was worth making that change I would have done it before I shipped it to you. AL K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 20, 2003 Share Posted December 20, 2003 Another upgrade if anyone is curious, I received 2 more ES600s from Al K. early this week and installed them in my La Scala pair with the Altec 511b and the Altec 902B. The La Scalas run as two ways with the ES600s are very impressive sounding. The word that keeps coming to mind listening to them is coherent. The crossover between the two horns is really unnoticed, the lack of interaction between the drivers really makes everything is the crossover region sound very clear without the smearing of most other speaker. The sharp crossover and the Altec driver allow a single horn/driver to handle everything from 600hz and up which is giving a naturalness/coherence to the sound which is addictive. If anyone wanted a 2 way 'Heritage' system this setup, or a similar configuration on a Belle, is a heck of a combo. For a K'Horn the crossover point would need to be lowered. The 902B can go lower and Al's extreme slope will help prevent it from being damaged from overexcursion. Some of the other Altec drivers can handle quite a bit more power then the 902s but from what I've read they get that at the expense of high end response. Shawn Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 20, 2003 Share Posted December 20, 2003 Shawn, If I had the money I'd love to have a pair of these with TD-4003 drivers on top of the Khorn bass bins and Al's new network. Rick Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 20, 2003 Share Posted December 20, 2003 Rick, "If I had the money..." That is an understatement... aren't those TAD drivers something like $2000 each and the horns around $2500 a pop? Those drivers are rated to 600hz... from what Al was saying to work on a K'Horn you would need to go lower then that somewhere around 400 to 450hz. The Altec 902 (bought for $89 a piece) are rated to 500hz and go down to about 400hz on a 511b (about $55 each) horn before really dropping off fast. Not sure how low you could go with a 902 on the K400 as I didn't have an adapter to go in that direction. Shawn Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 20, 2003 Share Posted December 20, 2003 Right now I have to be satisfied with what I have. Big bills coming up in January. Next week I'm going to put the ALK parts together though I'm using the Harmony 1uF in my AA right now. With the relatively inexpensive tweaks that I have done on the Khorns, and with tube amps, they are sounding better than ever. Plus with the new veneer they look fantastic. I want to thank all the folks on the forum for all their help and advice in 2003, wish all a great holiday and a happy, healthy, and prosperous New Year. Rick Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 21, 2003 Share Posted December 21, 2003 Rick, "Right now I have to be satisfied with what I have." Nothing wrong with that at all. Being satisfied with what you have is a great thing! Sure saves wear and tear on the wallet too. " Next week I'm going to put the ALK parts together though I'm using the Harmony 1uF in my AA right now." Let me know if you have any questions on that. Good luck, Shawn Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted December 24, 2003 Share Posted December 24, 2003 Al, In reading your response to a post above, you mentioned that the extreme crossover network would need a bit more work in order to be used with the Klipschorn. I was wondering about this, since the Type A replacement network works in Klipshorn, Belle, and LaScala. I've just moved my networks from my LaScala's and put them in a pair of '73 Klipschorns. Thanks and best regards, Dee Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 24, 2003 Share Posted December 24, 2003 Dee, Al's Type A crossover keeps the stock crossover point of 400hz. That is why it works in all three units. The ES600s units I have raised the crossover point to 600hz. The La Scala and Belle's woofer horn can reach up that high, the K'Horns (with its more complex folding) can't. To duplicate a similar setup to the 2 way I'm running on a K'Horn would require basically an ES400 or maybe ES450 from Al. Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 24, 2003 Author Share Posted December 24, 2003 Dee, I have not been monitoring this thread very closely lately. I figured it was about dead! That's why I'm a bit late responding. The "A" series replacement uses a 6 dB / octave or first-order crossover for the woofer / squawker transition. This type of filter is so sloppy that it is nearly impossible to predict where the actual crossover frequency actually is in any given speaker. The natural rolloff of the horns takes over. The measured crossover frequency of the network alone even changes with the load resistor you put on the woofer connection when you measure it! That's why it works equally well in the Khorn, Belle or LaScala. The extreme-slope network is a different story. This type of filter nails the crossover exactly where you want it. If the termination is not correct, the result is a rough passband with the crossover frequency still exactly where you want it! This is why I have gone to extremes to design the woofer filter to actually utilize the inductive part of the woofer voice coil impedance. I have just completed the computer design for the 400 Hz extreme-slope network intended for the Khorn. I have assumed that the Khorn woofer has roughly the same complex impedance as the Belle. I would like to have somebody verify this before I declare the design as complete. I need a volunteer who has a Khorn, an oscilloscope, an AC voltmeter (AC VTVM), an audio signal generator and a frequency counter to do a simple measurement for me. It would involve measuring where a large capacitor (about 160 uFd) resonates with the voice coil inductance. I can't do it myself because I don't have a Khorn! It will be a very simple measurement, but I need somebody who has all this stuff to do it! Anybody interested? Al K. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted December 24, 2003 Share Posted December 24, 2003 Al, Thanks for your response. That will be interesting to see how the Khorn woofer compares to Belle. I've got the Khorns, but not the testing gear. I'm certainly available to offer my Khorns to test if there is someone around Little Rock to come over with the gear and set it up. Just let me know and we can set up a time. Dee Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted December 24, 2003 Share Posted December 24, 2003 ---------------- On 12/24/2003 10:24:49 AM sfogg wrote: Dee, Al's Type A crossover keeps the stock crossover point of 400hz. That is why it works in all three units. The ES600s units I have raised the crossover point to 600hz. The La Scala and Belle's woofer horn can reach up that high, the K'Horns (with its more complex folding) can't. To duplicate a similar setup to the 2 way I'm running on a K'Horn would require basically an ES400 or maybe ES450 from Al. Shawn ---------------- Shawn, Thanks. I am such a non tech type that I require "Idiots guide to ___________________" for help in understanding most stuff. That does make sense. Dee Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 24, 2003 Share Posted December 24, 2003 I don't have enough of the necessary gear either. But, if there is anybody in or near Rhode Island who has the equipment, I'm willing to volunteer my Khorns for the test. Rick Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 24, 2003 Author Share Posted December 24, 2003 Dee & Rick, I can only hope that somebody reading this thread who has the equipment will volunteer. The oscilloscope method will only be able to measure the impedance at one frequency. It isn't possible to get a nice curve over the woofers range. That takes other equipment that vary few people have. The 160 uF cap will resonate with the woofer inductance someplace. That's where I will calculate the complex impedance. If I'm right, that will be at or very near 400 Hz. John Warren would be a good man to do it if we could get his attention and interest. Al K. Quote Link to comment Share on other sites More sharing options...
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