soundog Posted December 15, 2001 Share Posted December 15, 2001 Thanks to this site, I bought a pair of Altec 511B horn lens on ebay. I've installed the K55s on them and they are a very nice improvement on the K400. Although the 511s are rated at a 500Hz bottom, they seem to be doing just fine with Al's ALK crossover at 400Hz. I'm listening to see if there anything missing between 400-500Hz. Will get out the Shack meter and the Stereophile test CDs later and check it out. But music sounds great and that's what counts. People have written about the Khorns midrange being it's weakest point (even as is IMHO the Khorn beats almost anything else out there at any price!). It seems that the problem is the horn design not the drivers. I had to get adapters from Parts Express and will have to drill new holes in th 511 flange (the drivers are gerryrigged with one bolt now - and it still sounds great!). I have seen mention of an Atlas adapter that was made speciffically for mounting Atlas drivers. It incorporates a 2" extension and I was wondering if this was to adjust a 500Hz horn mating with a 400Hz driver. The K400 is two inches longer than the 511. I'll have to get at least one to find out - anyone know the story on this or where I can purchase the adapters (I emailed Atlas but no response yet)? ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
John Warren Posted December 15, 2001 Share Posted December 15, 2001 I did this years ago, 511Bs on the K-55V and later M and I thought it was time (and money) wasted since distortion is driven by throat size. Once the ears came off "Beraneck learning curve", the Altecs sounded "just as good" as the PWK horn. The headaches started to come back, too. I eventually sold them to a theater owner in Medford, MA. The place burned and was then torn down to make way for a senior center. Quote Link to comment Share on other sites More sharing options...
soundog Posted December 15, 2001 Author Share Posted December 15, 2001 I never got anything but enjoyment from my Khorns ... no headaches even after hours of listening. I listen longer now that I have a tube preamp and Perpetual Technologies correction engine and DAC. So far the 511Bs produce an improved sound using my components - by the way I'm also using Al's ALK crossover upgrade and a new version of the K55 (bigger magnet - no bug screen). I guess only time will tell - I'm not selling my K400 horns in the meantime. ------------------ Soundog's HT Systems This message has been edited by soundog on 12-15-2001 at 01:13 PM Quote Link to comment Share on other sites More sharing options...
eglinski Posted December 15, 2001 Share Posted December 15, 2001 Sound Dog, Are the Altec 511B horns mountable in the K-horn cabinet without modification? still room for tweeter and do the 511Bs need to be dampenend thanks for the info. Quote Link to comment Share on other sites More sharing options...
soundog Posted December 15, 2001 Author Share Posted December 15, 2001 It would be tight but possible, tweeter would have to be mounted vertically along side, new cutouts would have to be made. The 511B is bigger than the K400. They are also curved and flare outward in the front which would make the use of grill cloth difficult. I'm spray dampening and repainting the horns ... just finished another coat. Not sure how or where I'm going to mount them yet. They are louder than the K400s so I'm going to experiment with the attenuating taps on the ALK but the damping may quiet them a little so I thought I'd wait. I drilled them and properly mounted the K55 replacement drivers and they even sound better. At higher volumes I can detect some slight ringing so damping is needed. ------------------ Soundog's HT Systems This message has been edited by soundog on 12-15-2001 at 08:44 PM Quote Link to comment Share on other sites More sharing options...
soundog Posted December 15, 2001 Author Share Posted December 15, 2001 John- What equiptment do you use in your system? ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
TBrennan Posted December 15, 2001 Share Posted December 15, 2001 When damping 511Bs pay particular attention to the "lips", the part that extends forward from the mounting flange. Some later 511s had a damping device inside the lips. Also on later 511s Altec installed silicone rubber where the 2 halves of the vanes inside the mouth meet. Earlier 511s have the vanes halves welded together. You can easily cut the weld and run a bead of rubber in the joint. Under no circumstances cut the vanes out, this mod is sometimes bandied about and is a complete waste of time. I cut the vanes out of a 511 and there was no improvement, just several hours of time plasma cutting, grinding and polishing wasted. Bolting the 511 securely to a baffle and a rear support bracket also damps the horn a great deal. This message has been edited by TBrennan on 12-15-2001 at 10:44 PM Quote Link to comment Share on other sites More sharing options...
John Warren Posted December 15, 2001 Share Posted December 15, 2001 an MA6100 (preamp section only) plugged into a couple of MC30s. Quote Link to comment Share on other sites More sharing options...
soundog Posted December 15, 2001 Author Share Posted December 15, 2001 ok, I'll bite ... what's a MA6100 and an MC30? Sounds interesting. ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
soundog Posted December 15, 2001 Author Share Posted December 15, 2001 Tom- Did you break the welds and silicone the vanes on the 511 on your web site - if you did it's sure a neat job. I see the weld, in fact the back part of the vanes aren't welded producing a "slot". Cutting out the welds look like a real job ... not sure I want to attempt that - I don't belong to the boilermaker's union .... I've treated the entire outside surface with a sound dampening spray and after its good and dry (48 hours) and after I paint them with black spray enamel, I will apply the rope caulk following the model on your site. The dampingspray has produced a real improvement, I like them. ------------------ Soundog's HT Systems This message has been edited by soundog on 12-15-2001 at 11:23 PM Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 16, 2001 Share Posted December 16, 2001 Hi Guys, For what it's worth, I put 511 and 811 horns in my 3 Belles and crossed them over at 700 Hz and 10K to the T-35. I love it to pieces! I stuck "dynamat" stuff on the top and bottom behand the flange and above and below the lips. It still rings when the "teeth" are struck, but nothing's perfect I guess. You can click on the little house below and see all the details. Al K. Quote Link to comment Share on other sites More sharing options...
soundog Posted December 16, 2001 Author Share Posted December 16, 2001 Al= You and Tom Brennan gave me the idea and inspiration for doing this modification. I ran into trouble when I found that the Klipschorn's woofer was designed to go only to 400Hz. So I've had to use the K55 driver - I have both the V and M models. The former are in my LaScalas and the Ms are in my Klipschorns but I'm using non branded replicas that I got from Layne Audio - they have heavier magnets and no bug screens. They sound better than the 20 plus year old Ms. Not sure if that's because they're better or just newer or both. I was worried that the 511B would produce a "hole" between 400 and 500 Hz since the 511B lens is a "500Hz" horn lens. I'm using your crossover set to your recomendation for the M (vs. V) driver. I was going to change the taps but the spray on dampener has eliminated the ringing and seems to reduced the loudness (or the perception thereof) of the 511B vs. the K400. So I think I'll leave your crossover as is. It is truly an improvement in midrange clarity and definition. Tom suggested a way to get rid of the teeth ringing (above) but I'm not sure I want to fool around with welds especially since it sounds so good as is. ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 16, 2001 Share Posted December 16, 2001 Soundog, I started by grafting the K55V driver on the Altec 511 using my "A" crossover. It worked fine for the Belle and should be ok for the Khorn too. You are tied to the K55 driver though. It is tough enough to handle the 500 Hz crossover. The JBL drivers I am using are not. I found that crossing the 811 horn down at 700 caused no hole. I assume crossing a 511 at 400Hz is ok too. Actually, with the 6 dB / octave crossover, it's hard to tell where the actual crossover frequency is anyhow becasue it's so gradual. The autotransformer in the squawker helps to protect the squawker driver from the deep lows too. If you want a real treat, try rotating your K77 tweeter to vertical position! AL K Quote Link to comment Share on other sites More sharing options...
soundog Posted December 16, 2001 Author Share Posted December 16, 2001 Al- Thanks = I already had the T-35 tweeter in a vertical position on top of the cabinet. Now it's kind of crowded with the 511B up there too ... on one I also have your crossover up there too so its really crowded (I,ve been comparing K400 to the 511 won). I.ll have to figure how I want to mount everything ... You did a very nice job but since I'm in the basement I'm thinking of just mounting the 511B to a study baseboard, maybe with the equally naked T-35 along side. ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 16, 2001 Share Posted December 16, 2001 Soundog, Yep.. I remember now that you sent me some pix of the tweeter. I think the 511 is a better horn mainly becasue of the rounded front. I think it finishes off the exiting sound waves all around it better than a flat front like the K400 or K500. That's just a non educated impression though. What I don't know about horns would write the book! Al K. Quote Link to comment Share on other sites More sharing options...
John Warren Posted December 16, 2001 Share Posted December 16, 2001 you need to hear an Edgar midrange horn driven by an Audax PR170Z0. Quote Link to comment Share on other sites More sharing options...
soundog Posted December 16, 2001 Author Share Posted December 16, 2001 Thanks. Maybe I'll get a chance to at the THE or CES in Vagas. Is this part of the system components you listed previously, I don't know what those model numbers refer to. ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
edster00 Posted December 16, 2001 Share Posted December 16, 2001 soundog, The stuff John was referring to are McIntosh pieces. The MA6100 is an integrated amp from the '70s and the MC30s are 30 wpc tube amps from the mid to late 50s I believe. ------------------ Ed W Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 16, 2001 Share Posted December 16, 2001 John, I have seen photos of the Edger horn but I haven't heard one and I doubt if I could fit one of them inside a Belle! I did look into using one of the Klipsch professional Tractrix horns but the price was too high for me. The Altec honr are cheap on eBay. Quote Link to comment Share on other sites More sharing options...
TBrennan Posted December 17, 2001 Share Posted December 17, 2001 Edgar saladbowls sound very good but are not supreme. In a couple of listening sessions at my place this week using various JBL and Altec drivers on my 511s, my saladbowls and Paul Eizik's homemade tractrixes there was no clear winner. Several guys from the Chicago Horn Club listened and some liked this and some liked that, some liked everything, why not, everything used was good gear. Quote Link to comment Share on other sites More sharing options...
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