Erland

Nothing of couse. My quiestion is related to the following: All manufactorers of horns in general, and in this case PWK in special calculates the dimentions of the horn in accordance to the frequency range of operation. Since this is my first DIY horns, I like to build the basshorn as close to the original spec as possible. By changing the the thickness of the building material, (even by 1/32') the size of the horn will be slightly altered. So effectively by using a building material that is like 1/3 thicker than the original construction, you are building a horn slightly narrower than the original. In my case the the alternative is not as thick as 3/4 but 19/32'. Would this reduction in horn size be audible/measurable? By using a thinner building materia, the horn gets slightly larger. In my case with 15/32' plywood, the enlargement is minimal, and I find it hard that building accuracy even at the factory is that precise. Anyway, the question still stands... The other side of the same question is ridgity (does it spell this way?) of the horn. With like a 3/4' horn section, you get a much more ridgid construction that will be more resistant for internal vibrations. Is this a more important issue? Will a slightly reduced size of building material like 15/32' make the horn more exposed to internal vibrations? Anyway, when writing this, I recieved an email from a capenter I know, hwo told me that the Russian Birch grade A (in Norway referred to as Premium q) that is sold as 12mm (15/32') actually is the same as sold in US as 1/2, so that makes the choice easy for me, but in relation to the posters who claims that it does matter if you alter the size of building material, the question of experiences still stands. Regards Erland

There is some tube forums out there.... Log on to any of them and let the collectors market decide the prize. You will get whatever thy are worth. Good luck

I guess I have to be careful not to get the editor of Stereophile on my neck here, but yes you can have a copy of the soundfile. I am awhare that not many is willing to put their email adress on the net, so how do we do this? I am new to this forum....

Consistes of: Double input PSL from Borderpatrol EZ80 rectifier tubes Double Borderpatrol chokes for each channel Black Gate VKZ and NX Electrolytic Capacitors Caddock High Voltage Resistors Audinote Tantalum Resistors in singal path Sonicap Premium Signal Capasitors Stevens&Billington Transformer volume control Shalco Step attenuator and input selector Tung-Sol NOS 5687 signal tubes All Wiring of 99.99% 18ga solidcore silver Constructed to be 100% dual mono, and may be cut in two and still play I am proud to say that I have never heard anything like it, regardless of prize or manufactorer, and represented a massive upgrade to my system. Amplifiers to match it to follow when my K-horn project is complete.

Here it is....

I will get out of the office and head back home now (it's 8pm over here), so ill post a couple of pics in an hr or so.

Thanks for the advise HarleyMo, So maybe a pic. of the build of my "Mother of all preamps" project an't out of place on a speaker forum then.

May I suggest the test and sampler CD from Stereophile. Track 2 on the CD has helped me a lot when working on phase, imaging and listeningposition. The track contains examples of a Fender base guitar played first in separate channels, and then out of phase and last in phase. Since the test "singal" contains not only a tone, but a real instrument, it is so much easier to determine when things fall into place. I am sorry to say I do not have it with me, and will not have it in my possesion for another 8 days, but if you can wait that long, I can send it to you by email. Regards Erland

This ones

Thank you very much for the advise. The woofer I am going to use is a pair of new K33's

Thank you very much. So I am on the right track then... By the way, I looked at the wooden midband horns you posted a pic. of in the "Idiot question" thread. What kind are they? I understood that the Trachorns was only avaliable in black paint, and tried to make a pair, but after several attempts of bending layers of ply, I gave up and ordered a set from Al. After all, a black horn is better than no horn at all, and I rather spend the time working on the basshorn.

I have one that consists of 5 pages describing all parts in detail with spesific angles I have enclosed the first page for reference. Does it look familiar?

The only plans I have been able to get hold of is some with German text on, and converted to millimeter. Tho hole size of the woofer motherboard is 335millimeter (equals 13.188 inch)

HarleyMo, Thank you very much for the great picture. I am in the process of building my first K-horns, and your pic explained a few details I have been wandering about. If you have more of them, please post them. Thanks E

I am in the process of building a pair of K-horns. I am living in Norway, and the dimentions of all building materials avaliable is in millimetres and not in inch. However I have found a supplier that has premium quality birch plywood from Russia. The dimentions given for the K-horn is for the front and sides 3/4' and the horn itself 1/2' This dimentions is not avaliable. For the front and top I can get18 mm (equals 23/32') or make a special order of 20mm (equals 25/32). For the horn I can get 12mm (equals 15/32) or up to 15mm (equals 19/32). I am most tempted to go down to 12 and 18mm, but I like the hear if any comment or experience on this? Will make much difference if the horn is 1/32' off on each side? Is the factory made horn that accurate in the first place? I will use the K33E woofer, K55V driver monted on Al K's trachorn, and the C125 tweeter from Bob Crites. Crossover will be Al K's ES400/ES5800. As the trachorn is quite high, I consider to place the tweeter below to get it in heads listening position. Does this make sence? I have seen them placed vertically on the side of the squaker. I do not find this a good solution, as this may result in a very narrow sweetspot. Any suggestion or experience is welcome. Regards Erland

Hi Wolter, I suggest that you have a talk with Al Klapenberger http://www.alkeng.com or Bob Crites (frequents this forum) regarding crossovers for hornspeakers. They probably know more than the rest of us all together. Good luck

Hi Dannyboy, Be awhare that some has experienced a "humm" from the amplifier that obviously transferes to the speakers due to the hz difference. This is mainly a problem on sensitive highend tube gear. A stepdown transformer can be bought in most DIY homebuilder where thay sell electrical equiment. Be awhare of BIG price differences that not neccesary realtes to the quality. Since I am loccated in Norway, I do not have a specific shop to recommend in Germany. But....do you really need a stepdown? Most electical equipment, especially the types made in Japan, are designed for "multivoltage". They have a switch in the back to set the voltage. The only thing to switch does, is to reconfigure how the wires hookes up to the AC transformer. If there is no switch n the back, you most likely have to open the "box" and switch the wires manually. If you not feel confident to do this by yourselfes, a radio equipment repair shop will do it in a few minutes. If you go for the stepdown solution, it may be practical to go for two or tree smaller stepdowns instead of a massive 2-3kW one. Due to the size of the actual transformer and heating/cooling, it will be a BIG pice of kit! I have one with a maximum converted output of 110VA and the pirce are about $90. A 300VA is about $170. These are about the size of a small shoebox. If you need some additional advise or links to websites, please let me know. Erland

Maybe the subject i strarted is a litle "sensitive". I should know better that using "Best" in the title on a forum like this. We all hva differnet preferences, so what's best is hard to determine. Againg thank you all for the good inputs. I have to admit, I am not shure wich way to go yet. Somethings tempt me to copy the original, and then experiment from there. But it is also tempting to rely on others experience and skip a step here[] I still have some time to think about this while building the basshorn.

Thank you for your kind offer JJK, But my purpose here is not to make a bargain. My goal is to make the best sounding and looking Khorns possible. Cost no object (within some reason). At the moment the ALK eng. crossower, maybe with the Trachorn, that seem to be the way to go. Another thing....anyone of you heard of the Mundorf M-caps. The silver in oil verson are magnificent for DIY, but to pricy for comercial use. The std. M-cap I now used in the new B&W Diamond Nautilus series. I do not know who sells them in the US, but If you want to know more, I can possibly supply some english written information. Regards Erland

Thank you Al. I looked at the picture of the Trachorn on your website. Definately interesting! Are a alinco driver like the K55V or similar Atals drivers the best for this horn? What are the tweeter used on the picture? Definatley not a K77? Regards Erland

Thanks to all of you for good input so far. I have some drawing that apear to be original, but the measures are converted to european (from inch to mm). I have not started to build yet. Bass elements will be K33E Midrage K 55V - K401 horn Tweeter K77M All from Bob Crites If you have the original construction plans for the basshorn and are willing to share, my email adress are erland.solbakken@nmsc.no If you like to see my costr. drawings, please send me an email. I have found some pictures of the 50th ainversary Khorn, and my plan is tho build something similar, but using 1,5' Mahogny ore Rosewood on the outside of the birch plywood. The supply of high quality plywood are very good here in Norway, so the possibillity that this can be a success are absolutely present.

I am building a pair of Khorns. Why not buy originals, you may ask....Because I want the sound but with better looking woodwork. Since I have the tools and the skills, I tought it would be an interesting and challenging project for the winter. Original parts are being used, so we are not talking about a clone here, more like a Khorn "signature edition". I have a pair of RF5's in my system, and have a litle listening experience with Khorns, but not much. I have been looking at the crossower's avaliable, and read a lot on the web regarding the subject. Especially the company ALK engeneering cought my interest, and I have had some communication with a person who found their modified crossower a considerable uppgrade. Does anyone on this forum have other recomendations or suggestions for such crossower. Thanks Erland

It is good to read that I am not the only one who have such experience with Bob Crites. I am building a set of Khorns and I am buying the parts from Bob. A really hounest and helpful person that there is a pleasure to deal with! Erland