Benesesso Posted December 9, 2003 Share Posted December 9, 2003 Thanks, Al. I think I will try it both ways and report here what it sounds like-to me. I also found the excellent thread on different squawker horns, etc. It's all SO interesting and informative. The issue of horn ringing has also made me think-someone else reported that he found that deadening the 400 horn helped. I am going to see about coming up with something to REALLY deaden them-just short of pouring concrete around 'em. Might also try to pick up a pair of Altec horns when I'm back there. Benesesso Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 9, 2003 Share Posted December 9, 2003 Benesesso, I tried damping the metal K500 horns in my Belles. It is an improvement. Al K. Quote Link to comment Share on other sites More sharing options...
Benesesso Posted December 9, 2003 Share Posted December 9, 2003 Belles-beautiful speakers. What did you use to dampen them? I could have one of the welders here weld some stiffeners on the outside, and build a strong, stiff steel frame around them--or just surround them with something dense--and well attached. Naturally I'm now also interested in the Altec 500 horns-had a pair a long time ago in my pre-Khorns days. Didn't realize how good they were, but I did know how awful the big wooded boxes were! Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 9, 2003 Share Posted December 9, 2003 Here is an inexpensive, effective means of dampining the resonance of a K400 horn Rick Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 9, 2003 Share Posted December 9, 2003 The rope calk should do the job nicely. I used some stuff similir to "Dynamat". It's asphalt sheet with glu on one side. You can get it at any auto parts store. It's used to quite cars by putting it under floor mats. Al K. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 9, 2003 Share Posted December 9, 2003 Here's a picture of the damping material on the horn of one of my Belles. Those particular horns are now in my "Heresy on steroids" speaker in my den. The Belles are using Altec 811b horns and JBL drivers now. Al K. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 9, 2003 Share Posted December 9, 2003 Al, I just got a pair of "Baby Cheek" tweeters from a pair of Sentries sound very nice so far. I'll know more when I get rid of the fluid in my ear from a virus I picked up in Pennsylvania. I'm going to rope-a-dope them and put them in boxes and wire them so I can switch them in and out for a quick A/B. I got them for $100/pr so I can't loose on them. Rick Quote Link to comment Share on other sites More sharing options...
Benesesso Posted December 10, 2003 Share Posted December 10, 2003 Al, and others, All these great posts have really made me rethink things. It is finally dawning on me WHY, other than cost, do so many of you have beautiful Belles and er, uh, functional La Scalas instead of Khorns. Belles and La Scalas probably sound better WITH a sub than Khorns-with or w/o subs. So, I'm thinking of getting a pair of either and also using an Altec 511B mid horn, crossed over fairly low-starting around 300-325 Hz. I wonder what driver to use on them- Altecs, JBL or Klipsch? Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 10, 2003 Share Posted December 10, 2003 Benesesso, Follow the threads here on the forum about tweaks for your Khorns, then get a good tube amp . They and you will appreciate the sonic improvement. You will relegate those subs to HT only. Subs just muddle the bass from the Khorn's sharp attack of bass notes. Most SS amps are just too noisey with crossover and PS diode spikes in the sub-watt region for Khorns. That's what makes them sound harsh with SS. A class A biased FET amp would be what I'd want if I went back to SS. I have rebuilt my AAs with modern poly/film caps and have now incorporated the "bridge cap" Al recommends in this thread. Soon I will build some ALKs to try. I have also damped the Squaker and Tweeter, put the fuzzy side of some velcro around the opening of the baffle of the Squaker, and assure that the bass horns are properly coupled to the corners. I just use my SW-15 with the Heresys now. With both vintage PP and my 300b SET the sound is so much better than it ever has been in the 25 years that I've had Klipschorns. Rick Quote Link to comment Share on other sites More sharing options...
Benesesso Posted December 10, 2003 Share Posted December 10, 2003 Yes, I've been reading. So far all I have done is convert the AA's to A's--much better on the high end, where I probably can't hear too well anyway. But for the first time I could easily hear and ID that a tambourine was used on one of my fav. songs, "The King Must Die" by Elton John, "Live in Australia" CD. So, I am somewhat reluctant to change back to the AA and add the cap., but I am going to do it-it's easy enough. I got some caps. from work--the electronics tech. told me they were 1 mFd, and "probably poly". They are little rectangular white plastic caps, about 1" X 5/8" X 1/4". No markings except for 1J250, whatever that means. I don't have a cap. tester-maybe I should ask him to measure them. I'm also going to wrap the squawkers with the heaviest rope-tape I can find. Wish I had them back at my nuke plant in AZ-the vibration guy could excite them and tell me just how they ring before and after. But that's about 3 years away. BTW, I read a nice writeup about all of Altec's VOTT equipment, and the writer said that both the Altec 811B and 511B horns "ring like cowbells", so if I manage to get a pair I'll wrap them too. Tube amps-never did get any replies about driving a Paraglow with my Crown SL-1 SS preamp, but I see that the Foreplay tube preamp is not too expensive, even with the extras. BUT, in order to get all that (Foreplay and Paraglows) over here to Italy will be a little problem. I don't find that crossing over from the Khorns to my huge Earthquakes causes any muddying. I've tried it both ways, and I MUST have the strong low end that I've never gotten from the Khorns alone. I set the crossover at 40-50 Hz-don't know the rolloff rate, but it works well there. Any higher and it does get muddy. BUT, most music has nothing way down there-usually just organs, electronic stuff and the lowest notes on doublebasses. But when it's there it's great-almost religious! Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 24, 2003 Share Posted December 24, 2003 The ST-350s had a siblance that was annoying so I took them out of the circuit. Believe it or not the K-77s sound better with Al's "bridge cap" mod. I'm not going back. I highly recommend this simple, inexpensive mod for anyone with double A networks. Rick Quote Link to comment Share on other sites More sharing options...
Benesesso Posted January 2, 2004 Share Posted January 2, 2004 I just finished converting my AAs back to AAs and added the bridge cap-supposed to be 1.0 mFd, but they are unmarked. But the difference is amazing. I'll have to try re-reading all these messages, but what Hz area of the midrange is affected by this little cap? They sure seem "smoother" now. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 2, 2004 Share Posted January 2, 2004 Bene... The cap does NOT change the midrange at all. What it does is reduce the loss in the tweeter filter and reduces low (mid frequency actually) frequency energy entering the tweeter. Al K. Quote Link to comment Share on other sites More sharing options...
Benesesso Posted January 2, 2004 Share Posted January 2, 2004 Al, OK, I think I've got it now. When I read the previous posts about the trumpet blare that was eliminated by the bridge cap., I assumed it was from the squawker. In any event, the tweeters seem to be as extended as they became when I first modified my AA's to A's. Am I hearing anything different from that dip/notch/whatever at ~3,500 Hz? Was that freq. being emitted by the tweeter in the orig. AAs? This is all very confusing for non-electronic types like myself, to whom caps. block DC and transmit AC. Also, I should have written 1.0 uFd, not mFd! Makes me wonder why a Farad is so big! Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 2, 2004 Share Posted January 2, 2004 Bene, The reson you hear better highs from the A than the original AA is because the AA tweeter filter is not a proper design. As it happens, the bridging cap compensates somewhat for the design error reducing the loss. This give you what converting to the A gave you plus the notch sharpens the filter skirt. This is like making a 3rd order filter into about a 9th (guess, I didn't calculate it) filter. The adea isn't to remove one specific frequency. it's to sharpen the skirt if the filter. This removes more completely and quickly energy that is out of the tweeters range. The out of band frequencys are to go to the squawker and only cause problems if they reach the tweeter. Who needs two drivers playing the same thing at the same time? This, in my opinion, is the problem with the A network filter. It's also why I am advocating extreme-slope crossover networks now. The bridging cap makes the AA filter closer to an extreme-slope filter then it was. Al K Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted January 5, 2004 Share Posted January 5, 2004 This has been such a fascinating read! I have just converted my AAs to As, but would indeed like to re-try the AA with the bridging capacitor. Diodes were also removed at this time, and most of my listening is in the sub-watt (single watt) range, anyway. Thanks Al and others, and especially Al for all the work to support this really interesting crossover modification. I think I would like to do the AAs in a way very similar to what Rick has done, but will try with the existing capacitors, first. Erik Quote Link to comment Share on other sites More sharing options...
Benesesso Posted January 6, 2004 Share Posted January 6, 2004 Agree, fascinating. So what to do now? Wait for Al's extreme-slope Xovers for Khorns, or do something to my "bridged AA's"? I was thinking about ordering the Solen 2.5 mH air core, 14 ga. woofer inductors. Would they make the most "low cost" improvement, or should I try something else? FWIW, the tweeters now sound great-I hear things that I never did before. Great demo CD is the soundtrack from the movie "The Sting". Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 6, 2004 Share Posted January 6, 2004 Bene, I agree, the 2.4 mHy air core woofer inductor will make an audable improvement in the bass to the "AA". Iron core inductors are not linear. BTW, the Khorn 400 Hz extreme-slope network is designed, I just need somebody with the right equipment to verify the woofer voice coil inductance and then somebody to order one. Al K. Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted January 7, 2004 Share Posted January 7, 2004 Al, can I do this for you? I have a nice but basic Fluke meter, an old Knight Kit scope in excellent condition and a Simpson 260. I can lay hands on a VTVM also. I habe no idea in the world how to measure the inductance of a voice coil. My Khorns have the Jensen woofers, BTW. I have LaScalas with ALK networks with k-33 new production woofers. Off to Google to see if I can find a procedure for this measurment. Tom Quote Link to comment Share on other sites More sharing options...
Benesesso Posted January 7, 2004 Share Posted January 7, 2004 Al, Any idea about how much 2 of these new steep-slope Khorn Xovers will cost-especially the first pair (hint, hint). Benesesso Quote Link to comment Share on other sites More sharing options...
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