Good2BHome Posted February 10, 2003 Share Posted February 10, 2003 Here are the secret modifications that Dave Mallet referred to which he and Bob Lemker heard the results of at the last meeting of the DFW Klipsch Forum. They have been very kind in their positive comments. (Sorry, Dave for taking so long to post. Other issues.) <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> My goal was to improve bass response, tighten the bass and smooth the mid-range. In addition, didnt want to do anything that could not be reversed. I have been thinking about modifications to my Cornwalls for about a year. Im not a frequent poster on the forum, but I regularly lurk and take note of all the mods I see mentioned / discussed. The only semi-original modifications I made were the first two listed. The Bad News: All modifications were done at once. The Good News: They worked beyond my expectations! These modifications were made to a pair of stock (at the beginning) 1980 Cornwalls, with the B crossovers. Previously all contacts were cleaned with Caig ProGold with no noticeable improvement. I have a second pair of 1975 Cornwalls and in the future will take the time to do each modification separately to determine the actual secret, although my current belief is the 12 gauge silver wire was the most significant mod. There is a significant improvement in base response and it is tight. The mid-range is smoother, but there is still some work to be done with the mid-range. Modifications: Mod: Pure (.9999) silver, 12 gauge solid wire from the crossover to the woofer. Purpose: Improve bass response. The K-33 has a resistance of 3.5 to 4.0 ohms and any reduction in the resistance of the wire is a good thing. The silver wire was purchased from a jewelry wholesaler. I first polished the wire with Blue Magic, the finest grained metal polish I am aware of (so fine that you can polish the milky haze out of convertible rear window, which I have done). Second, I cleaned the wire with Caig ProGold. All of this was to prepare the wire for sealing with 1/8 commercial 3M FP-301 Clear heat shrink (Parts Express part # 082-026). This may seem obsessive, but my concern was to protect the raw silver from future tarnishing. Mod: Gaskets for the Squawker and Tweeter. Purpose: Reduce the vibration and seal the Squawker and Tweeter to the motorboard. Previously when swapping the Squawkers and Tweeters between the 1975 and 1980 cabinets, I noticed that there was rough flashing on the mouth of 1975 Squawkers. I filed off the flashing and placed on a very flat surface to be sure they were flat and found they werent. Then I checked the 1980 Squawkers and found that they too were not flat. So I checked the tweeters and they were not flat either. This made me concerned about the seal between the speakers and the motorboard. The solution was the gasket. The gaskets were made from a VE-1 Vinyl Damping sheet (Parts Express part # 268-030). The 10 x 13 piece is enough for a pair of Cornwalls and is about a 1/16 thick. Note: There was not a gaping space between the horns and the motorboard, but any space is not a good thing. Side benefits of the squawker gasket: 1) It adds addition force on the back of the speaker and this may reduce some vibration on the back and thus tighten the bass. 2) The vinyl damping material absorbs vibration from the motorboard and thus insolates each speaker from the other, to some degree. Mod: Installed a 2 x 1 x 22 ½ Hard Rock Maple brace on the interior side of the motorboard, between the Squawker and Woofer. Purpose: Reduce flexing of the motorboard and thus tighten bass. This idea was taken directly from Roger Floths article Equalizing the Klipsch Cornwall published in Speaker Builder on March, 1989. An additional benefit is to reduce some vibration to the Squawker and Tweeter. It is very important that the 1 face is milled very flat and smooth to make the best contact to the motorboard. The wood selected must be very stiff. Both Hard Rock Maple and Ash were suggested to me. I chose Hard Rock Maple. Mod: Monster Original from the back of the binding post to the crossover. Purpose: Reduce resistance. Mod: Dampen Woofer basket with rope caulk Purpose: Cut noise you dont want. Mod: Dampen squawker horn with rope caulk. Purpose: Cut noise you dont want. No changes were made to the wiring to the Squawker or Tweeter. I welcome the your comments, questions and hope to see some of you at the next DFW Klipsch Forum meeting Mike Quote Link to comment Share on other sites More sharing options...
Mike82 Posted February 11, 2003 Share Posted February 11, 2003 Thanks for sharing your experience, Mike. I have Khorns and also did did a couple mods. In separate steps, I changed the wiring (12 ga, 6N copper) to all the drivers and rope caulked the squalker and tweeter horns. The improvement in bass control was quite noticable. Also rope caulking the horns produced a definate improvement in clarity and high frequency extension. The effectivenes of this tweak was again proven when I dampened (using rubberized auto undercoating) the 511B horns I am using with the Khorns. The sonic improvements gained through reduction of resonance in the horns is pretty easy to understand. Given the short wavelengths of high frequencies, it would not take much vibration (i.e., resonance) to alter the wave propagation. Regards, Mike 1 Quote Link to comment Share on other sites More sharing options...
Freud Posted February 12, 2003 Share Posted February 12, 2003 Do you take some pictures? 1 Quote Link to comment Share on other sites More sharing options...
dbflash Posted February 12, 2003 Share Posted February 12, 2003 Thanks for the info. Danny Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted February 12, 2003 Share Posted February 12, 2003 Ditto. This is invaluable material for the Cornwall moder! I'm considering it... Quote Link to comment Share on other sites More sharing options...
Good2BHome Posted February 12, 2003 Author Share Posted February 12, 2003 Freud I'll post a picture this weekend. I appreciate those who have showed an interest. Mike Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 13, 2003 Share Posted February 13, 2003 Of course, we are also waiting to hear Bob Lemker's La Scala mods on the 23rd. Some of these sound perfectly applicable to the big ol' horns as well, and within the technical skills of us fumble fingered academics. Dave Quote Link to comment Share on other sites More sharing options...
dbflash Posted February 13, 2003 Share Posted February 13, 2003 Mike, I tried to find a copy of Roger Floths article Equalizing the Klipsch Cornwall published in Speaker Builder on March, 1989. I can find back issues but for some reason 1989 and 1990 are sold out. Where did you find it? I have been listening to my Cornwalss for 2 weeks now and I really am starting to like them. Thanks, Danny Quote Link to comment Share on other sites More sharing options...
Good2BHome Posted February 13, 2003 Author Share Posted February 13, 2003 Danny, Send me a direct Email and I will be happy to send the Floth article to you as 3 attachments. If there is any other interest in the article I'll post it here as 3 .jpg files. Someone on on the forum was kind enough to share it with me about a year ago. Mike 1 Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 13, 2003 Share Posted February 13, 2003 I have the entire Floth article right here in a webpage I made last year. http://home.earthlink.net/~ivol/klipsch_cornwall/cornwall_mod.htm kh Quote Link to comment Share on other sites More sharing options...
dbflash Posted February 14, 2003 Share Posted February 14, 2003 Mike and Mobile, Thanks. I went to Mobile's site and downloaded the info. Danny Quote Link to comment Share on other sites More sharing options...
Good2BHome Posted February 14, 2003 Author Share Posted February 14, 2003 Thanks Mobile, You're always on top of things. I agree with Mobile about Floth's article, the baffles may not be a good idea, at least not without crossover changes and maybe not then. I obviously think the interior brace is a good idea and may add the back exterior brace, but not neccessarly made out of plywood. More research and thought is necessary. As promised I will post a picture of the interior on Sunday. Mike Quote Link to comment Share on other sites More sharing options...
Good2BHome Posted February 16, 2003 Author Share Posted February 16, 2003 Attached is a picture primarly showing the 2" x 1" x 22" brace, the silver wire to the woofer, damping and Monster Orginial to the crossover. In addition on the left you can see the back of the latest mod, a 60 lb. riser, which is made of 3/4' plywood and lead. They definitely improved the image. They were constructed with the provision to add spikes in the future, which may or may not be necessary. Today, I'm installing P-traps on the squawker, that Bob Lemker loaned me, to try out and see if there is any improvement. This is a fun hobby and there is no end to it. Mike Quote Link to comment Share on other sites More sharing options...
TBrennan Posted February 17, 2003 Share Posted February 17, 2003 Mike---Are you aware that the P-Traps were developed by a fellow Texian down in Kerrville? He measured a number of the Atlas midrange drivers and found the 9kz flare in a number of them and designed the little trap to tame the flare. A modest fella, he don't like his name bandied about. Perhaps you know him. Quote Link to comment Share on other sites More sharing options...
Good2BHome Posted February 17, 2003 Author Share Posted February 17, 2003 No Sir, I was not "officially" aware that they came from Texas, but being a Texas native we are brought up to believe most good things originated in or near Texas. And Hope, Arkansas qualifies as near I'm interested. Is there more to the invention of the P-Trap story, without breaking any confidences, you are sworn to? Mike Quote Link to comment Share on other sites More sharing options...
mopar dave Posted February 18, 2003 Share Posted February 18, 2003 good2bhome, i noticed from the pic you are still using the old inductors. try switching to an air core type, 12 or 14gage. i changed mine two weeks ago and noticed that the bass had tightened up a bit. well worth changing. AL KLAPPENBURGER recommends solen 12gage. i used air core brand in 14gage, and i'm very happy with the improvement. i will be trying the motor board brace in the future, do you think there's a noticeable improvement? later dave Quote Link to comment Share on other sites More sharing options...
Louis Bartay Posted January 7, 2015 Share Posted January 7, 2015 Danny, Send me a direct Email and I will be happy to send the Floth article to you as 3 attachments. If there is any other interest in the article I'll post it here as 3 .jpg files. Someone on on the forum was kind enough to share it with me about a year ago. Mike Old thread...........I am looking for a copy of Roger Floth article on mods for the Cornwall and the image on this thread is too small and I can't read it no matter what I tried. If anyone has this Please email me labartay@verizon.net Thanks Louis Quote Link to comment Share on other sites More sharing options...
Schu Posted January 7, 2015 Share Posted January 7, 2015 well now... it's not really a secret then is it... Quote Link to comment Share on other sites More sharing options...
Chris A Posted January 7, 2015 Share Posted January 7, 2015 (edited) https://community.klipsch.com/index.php?/topic/139213-suggestions-for-cornwall-cabinet-upgrade/?p=1564697 https://community.klipsch.com/index.php?app=core&module=attach§ion=attach&attach_id=79774 Edited January 7, 2015 by Chris A Quote Link to comment Share on other sites More sharing options...
EmilC Posted January 7, 2015 Share Posted January 7, 2015 Mike I like the idea of extra bracing. Even my Crites Cornscala box could use some. Once you're all done, and especially if they're on carpet, try speaker spikes under all 4 corners of each speakers Quote Link to comment Share on other sites More sharing options...
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