Daan

WOW... amazing. I just send the link to some of my fellow horn-enthousiasts over here in The Netherlands.

THANKS ! Great thread to read with great pics. Nico

THANKS! This guy is me and I got a great idea now about how to proceed. Since these Khorns are of the "unfinished type" , it's no problem to make a top and bottom piece for them as shown in your thread Q-man So it IS possible to use them lying one side; that's good news! Nico

Thanks for your reply; does it make any difference wether he closes the backs or use wings? I have seen the wings are much wider [ about one metre from the back] ,than the closed backs on the 6th Anniversary Khorn for example. Closing the backs seem to be a incomplete solution compared to the wings advised by PWK in the Khorn manual, in that they have to stick out at least 25inch from the grilles on each sides? Forgive me if I overlook the obvious, just want to be sure of what I'm starting and the two methods seem to be so different. At this moment I have bought the K-C-FB Khorns since my friend's made a small misstake.... he did not tell his partner. [ooops] If closing the back is really enough to make these horns work, I'll do that so that there is a chance my friend will be able to get them into his household. It is a rather "compact" solution compared to the wings IMO.

A pair of Klipschorns !...... K-C-FB. Serialnumbers 5L194 and 5L195 I can not use them in the house we're living right now, but I could not let them pass.....

Thanks babadono and Moray for your replies. I was asking this for a friend who thinks about buying Khorns but does not have proper corners. When he asked me about it I could not give him a proper answer; I'll advise him to either close the backs if he buys theKhorns ,construct false walls like PWK suggest in his manual, or go for a different system. Moray; thanks for the suggestion about the other version of the University Classics. After listening at my place, this friend wants a big hornsystem as well and Khorns are regularly for sale here in The Netherlands. University's are nowhere to be found....one of the reasons I'm so happy that I found mine. We are going to look at a set of K-C-FB Khorns tomorrow which are affordable and can be adapted to suit his needs. He's has put the [already big] speakers he currently has, up for sale and has trouble, so he says to get " big hornsystems" out of his mind haha. It's addictive !

A question for those who possably have some experience with this; What if you don't have corners in a room to place the Khorns in ,but instead lay the basshorns on their side on the floor against the wall ? Theoretically this would be the same as putting them into corners, only now using the wall and floor as a corner. Placing the mid/high section on a shelf at the right hight [ear level].... would that work ? Thanks, Nico

If you want to go two-way, look for a 2" driver and horn combination. Ofcourse you still would need a higher crossoverpoint ,but you'll need other crossovers anyway if going this route.... It might be a good idea to think about going active like me; when you have another amp laying around and buy a MiniDSP, you'll be able to tailor just about everything to your liking. Also you'll be able to swap drivers when you want to and get the max out of the system; works for me. If you don't want to spend that much I'd suggest to stick with the three-way operation because they already sounded impressive when they still were in original shape ! I would add braces to the one not having them, as those rear panels are quite large..... The bracing inside the woofer compartment stiffen both sides of the compartment at the same and such is a good idea. ----BUT as can be seen on the pics, the existing ones make the woofer-compartment drastically smaller so mine do not reach from top to bottom. I left a space of 10cm open at the bottom and 5cm at the top. This makes the woofer-acces panels very stiff. . Nico

Just looked at the original documentation I have and it very much lookes like the right one with the braces is a original one. The other one is probably made for the speakerkit that was available at that time to build your own cabs. Everything from the braces, to the blocks that allow conversion from "low boy" to "high boy" , look to be original on the right one. If the crossover was located in the back and the controls on the woofer-acces panel, then I'm quite convinced that one is original. Nice !!

Musicook; congrats on your purchase, looks like you got some work to do but will end up with a pair of these great sounding monsters as well. They sound BIG when stock, and will surprise you even more when you do some work on the crossovers [caps] , clean the attenuators etc. I still have all the original parts like cobreflex horns plus drivers, crossovers and tweeters which are all of very good quality. Funny that the cab on the right shows the braces and the other one doesn't; I've seen pics of both versions and tend to think that in those days changes were carried out whenever the manufacturer decided so. Another possabiltity is that they are home-made and the one who build the one with braces spend more efford and time than the other one. The bass-section of this horn may surprise you when you are used listening to other hornspeakers; these horns easily reach into the midband like I mentioned in one of my earlier posts. [due to the simple fold I am told]. The original folder says that it is because of the "one mouth-opening" design of this horn, unlike the Klipschorn for example which is a separated design. You can also go two-way with these, I know a guy who is very pleased with the result.....

Thanks Moray, It's been a long time since I could listen to a system without having the urge to "change something".... We were used listening to three-way systems for years and never thought a two-way system could sound so good or even better. Only after using the time-alignment function of the MiniDSP everything seemed to "" sound right" . Having the woofer away from the mid/high horn for just over one metre it really makes a big difference to make use of this function. With the crossover set at 1100Hz [yep, that high] at 18Db/oct , the two drivers work perfectly together. This woofer/ horn design makes it possible to reach high enough for the Beyma mid/high driver to take over effordlessly, with the EV horn having a Fs of 400Hz. Lowpass is boosted gradually from 100Hz to 20Hz to compensate the basshorn's rapid rolloff, just as the highpass is raised to 20K to compensate the rolloff of the Beyma driver. Looking back , one thing is clear though; when looking for better sounding speakers... size matters. Nico

Well, after fiddling with the Mini-DSP a number of times and fine-tuning the settings, I felt no craving anymore to change anything. Every time we listen to music we enjoy the lively and complete sound with which these big boys draw us into the music. We slowly turn from technical listening to simply enjoying it ! A few weeks ago I made the speaker-grilles for the upper section and plans are to make a set for the lower section as well to give them a less "brutal" appearance. We had a visit of a man who ownes a very expensive system ; he couldn't believe that such a simple and relatively cheap system could sound so good. [he didn't believe in horns either... now he does.] What's left is to find a new owner for my stock La Scala's here in The Netherlands or better; a place to store them....

Looking at this thread again today I can see that some of you over-estimate my skills. I do not have calibrated measuring equipment, nor the experience to use them. All I have is my Phonic PAA-2 analyzer which helps me out from time to time when I don't trust my ears. So I'm a very simple guy who tunes his system by ear. That is why I did not change the Universal Classic enclosure in design and only cut-off the empty spaces that made it look bulky and like a ugly box. Before making any change at all, like putting the EV HR-90 horns in the La Scala's, I listen to it first for a few weeks together with my wife [ for more than 30 years already she sings in a choir and got a very fine-tuned hearing]. After a few weeks we swap things back the way they were, and check the difference. This way we were always able to determine wether the "new thing" was a improvement or not. Compared to the K-horns [we have heard K-horns many times] ,these horns go slightly less deep but have a much better "open sounding " bass and midbass" area. They can also easily be crossed over at 900Hz and this way provide a good basis for a 2-way system. Compared to the La Scala, these horns dig deeper, provide a much richer sound, again sound much less restricted and do not suffer from the colourations of the LS 's sidewalls. Having the mid/high horn inside the bassmouth makes the sound coming from one point which has broadened and deepened the soundstage, singer's voice coming from mid-air between the cabinets. These are our experiences without professional measurements, you may laugh about it if you want. All I wanted to share here with this thread was my enthousiasm for this project and maybe encourage others to refurbish old enclosures from the past so they can be enjoyed again today. Nico

Thanks for your comment but I don't know this expression, explain please? Nico So I guess when you have a party you hide your speakers ? Or do you crank them to impress the CROWD? Oh, that's what it's about. In fact our house is to small to have party's and we wouldn't know where to hide these speakers. And luckily we don't need to impress anyone anymore. We grew up a long time ago . Nico

Thanks, it really was special to work with " the old man " . We celebrated his 79th birthday last wednesday and he's still talking about it to everybody he speakes. Next week he'll come over and have a listen for the first time.

Thanks for your comment but I don't know this expression, explain please? Nico

Update; the La Scala's have found a new home. They are now with a guy who has a pair of original La Scala's as well. These have never been upgraded and he was amazed by the sound of mine when he came over to listen to them. So on one sundaymorning we moved my set of LS's to his place and positioned them next to his. After first listening to his pair we listened to the same music on mine and the difference in clarity, detail and frequency-extension was obvious right away. The [bigger] EV horns also made the sound come more into the room with a much wider sweet spot, something the new owner was really surprised about. And now about the Classics; as we went from 3-way passive to 2-way active filtering we were already aware of the better soundquality though we used a 18Db/oct. car-audio filter at that time. After looking at the professional "Groundsound" site I asked the owner Robert Sorensen some questions about it, which he prompty and with enthousiasm answered. In spite of his well explained anwers to my questions I still felt unsure about my capability to manage his system. So I asked around for a simpler system since I wanted to do measurements only with my PAA-2 analyzer and be able to use a system without possible hours of trial and error. I ended up with the miniDSP as a good candidate which not only was recommended by other users but also is more affordable for a newbie on active filtering like me. After ordering the "2x in, 4x out" in-a-box device and downloading the "advanced " plug-in I could start right away to experiment and get familiar with the system while the device itself was shipped. After a few evenings of reading the manual, reading on the forum and experimenting with the software I understood enough about how it worked to wait impatiently for the DSP itself. Six days later it was delivered and after connecting it to the laptop, synchronizing it and downloading the previously made settings the DSP played satisfactory right away! A few hours of fiddling with the settings later the Classics sound GREAT even with enough settings left which we did not even tried out yet... So for those who have just as much experience as myself with active filtering [NONE...] and want to go that way, I can recommend to try out the miniDSP. The Groundsound system will be better for the more advanced technician IMO with measuring equipment, something I do not have and I don;t want to go that far. I use my simple PAA-2 and my ears. Tomorrow we'll receive a experienced listener who has a very good system himself, so let's see what he's got to say about it. In the end I must admit; going away from a beautifull designed passive crossover and instead adding a amp, DSP and even more cables WILL IMPROVE THE SOUND. [for improving the looks for my wife I installed grilles to the upper half of the bass-mouth] Thanks for reading, I hope this helps a little for people with the same doubts as I HAD about going active. Nico

If that's what they call them where you live; yes, they are. They call them "trumpet-ports" over here.

After many years of lean bassresponse I went for opening the doghouse and bassports on the rear. It works very well and I am very pleased that the original look is still retained. After making a fixed panel inside the upper part of the cabinet I can either mount a closed panel or the one with ports, easy. Nico

Very interesting project, will follow this thread to see what you end up with.... I made some changes while building some projects and it only added to my enthousiasm in the end. Good luck and remember to enjoy the build itself. Nico

Curious as well what to expect ? I run a dedicated powerline starting with a isolation-transformer from the mains with great result; my acoustic mains-pollutionmeter simply is dead silent when plugged in. It screams like hell when plugged into a socket from another circuit in the house. BTW; did you know a "STETZERIZER" also has this effect on a whole circuit ? Inside these things is a simple condenser of 15uF 450 volts. Link; http://www.amazon.co.uk/CBB61-Motor-Starting-Running-Capacitor/dp/B005QIYONK Without my "Hifi Tuning" meter I would never had known that a simple capacitor cleans up a mains cicuit in this way. Maybe a tip to remember when you're in a radio-shack store.... Stetzerizers cost a lot more. Nico

The La Scala's are up for sale now here in The Netherlands, though I had my doubts about selling them for the past few months...... Have to make room again for putting the dining-table in the original position again, my wife wants the livingroom back to normal after months of tools, speakers and other stuff all around the place. I have to admit that if we had room for them we would defenately not sell them but that's how it goes sometimes. We only hope to find a buyer that will appreciate them as they are now. We're going for a "groundsound" active crossover that will allow us to adjust just about everything from crossoverpoints, slopes, time alignment etc. for the two-way University Classics. Will report how that goes so some of you guys may benefit from our experiences; after all a lot of you helped us to find the best mods for the La Scala's. Nico

Only since last week I removed the ALK Universals from my La Scala's ; best crossover for listening with low to moderate levels. I've heard the steep slope versions but always preferred the universals myself. Al does not make a secret about the crossover itself; you could build one yourself if the price is too high for you to have a set build by Aletheia. As for a sub; I agree with the comments made, no sub will exactly match with a horn. Only sub that I found suitable enough is the REL STRATA III , which can be dialed in precisely where you want it; remember I play at moderate levels and at high levels there's no sub that can keep up with the speed of a horn. [i ended up building a bigger hornsystem ]

Looks like my Decwares, nice job! Match them with the cornwalls and see what happens...

So since this afternoon, we're playing active two-way with the massive Beyma CP750Ti drivers and EV 940 horns inside the basshorn-mouths of the Classics. What stands out right away is that the C15-W woofers defenately like to be driven by more than the 6 Watts from the Decware Zen tube monoblocks; the Denon 100W amp keeps a firm grip on them even when fed bass-heavy material. They go deeper and with more control...not such a surprise ofcourse, but remember I sit only about 3metres from these monsters when listening. Also going from 3-way passive to two-way active is... well ....reveiling to say the least. We found out the resonance frequency of about everything in our livingroom by now [the neighbours probably did so as well]. Beeing concerned that the 940 midhorns would "fill up" the basshorn's mouth too much, I cut off the flanges so they are only slightly bigger than the original mounted Cobreflex horn. Also painted the 940's so they won't be visible behind the speaker-fabric that will be placed in the top-half of the cabinets. They sit on a wooden circle that in turn sits on a heavy steel bracket; those Beyma's weigh about 8Kg each.. The wooden circles allow me to rotate the horns horizontally plus vertically as the magnet can sit at any angle in there. After finding the best position I'll attach the horns themselves to a bracket which will fix that position. I feel like a "Frankenstein-creator" sometimes so to speak, but this is actually my REAL hobby, experimenting with all kinds of gear, reading and combining stuff with new ideas to find better sound.... hope I'll never actually find it ! Nico