Invidiosulus Posted April 11, 2003 Share Posted April 11, 2003 I did a mod on my heresy's that seemed to tighten up the bass a little. I took a piece of 3/4" mdf and cut it to the same size as the back panel of the heresy and cut out a hole for where the speaker terminals are and then I took a some longer wood screws then the originals and sandwiched the original back onto the cabinet with the mdf. I used the original back pieces to make sure I had the holes for the screws lined up right. Also, I used some self adhesive weather stripping on the mdf so it would seal to the back and not have any chance of vibrating when screwed down tight. The improvement is not greatly noticable and really only makes a difference when I crank up the volume. Before I did the mod I noticed that even when screwed down correctly the back of the heresy was vibrating a good bit at higher volumes and this seemed to be coloring the midbass somewhat. I am kind of curious as to why the heresy was built with only a 1/2" thick back. The back seemed to have more movement then the motorboard itself. One of these days I'm going to get around to trying the caulk on the horns. Right now however I'm kinda lazy and don't feel like opening up the cabinets again. I think for now I'll just try some caulk on my head because it tends to vibrate at high volumes(as does the rest of my apartment) causing some unwanted doppler effects I just thought I'd share. Peace, Josh Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted April 12, 2003 Share Posted April 12, 2003 Don't forget, rope caulk or duct seal, has a rather long break in period. Sometimes this can take thousands upon thousands of hours (so don't give up). The molecules in that stuff have to gradually align themselves in relation to the predominant musical vibrations, otherwise these molecules will act in a counter productive way. You will notice the sound becoming much more musical after the break in period. Ideally after a long break in time, there will be more blackness and even some beige and some puce hues. Eventually, there will be greatly enhanced transparency. It is the same if you were to try to stare through the opaque caulk, in time (a lot of time) your eye's gaze would render the caulking substance transparent by Le Chatlier's principle. It is like why the ice melts under the weight of the ice-skater. Same concept. Simple physics. This is related to why it is important to have your speaker wires going in the correct direction. Molecules know stuff, and everything is molecules you know. C&S Quote Link to comment Share on other sites More sharing options...
Allan Songer Posted April 12, 2003 Share Posted April 12, 2003 Hey C&S! Why not wrap your keyboard in caulk? Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted April 12, 2003 Share Posted April 12, 2003 How 'bout duct tape, scotch tape, masking tape, Maxell tape, or Watergate tape, HMMMM? I'm sorry, but if PWK thought that the baskets and horn lenses needed caulking, he would've done so...JMHO, FWIW, SNAFU, FUBAR, ETC. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted April 13, 2003 Share Posted April 13, 2003 My keyboard, and my head is already wrapped in caulk, since I ran out of duct tape, our National security would have it no other way. C&S Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 13, 2003 Share Posted April 13, 2003 What about some of that government red tape ? Lol, some of the things we ponder... Quote Link to comment Share on other sites More sharing options...
Deang Posted April 13, 2003 Share Posted April 13, 2003 In my original post regarding the tweak I pointed out that what set me on the course to caulking the basket was the nice clanking sound it exhibited when tapped. Even just gently tapping it. Now, imagine the pressure waves, coupled with the violent mechanical movement -- as that 15 incher starts chugging away. Anything resonating that's attached to the cabinet, increases the amount of resonance of the cabinet. Also, as the basket itself is resonating/vibrating, it transfers the energy back into the driver assembly -- causing a degradation in coherence. The less vibration the better. Anyone who is willing to argue to the contrary hasn't thought this through. I also want to point out that the woofer in the Cornwall goes up to 700Hz. We are clear out the bass range here. We are now into the critical lower midrange. The place at which the woofer meets the squawker needs to be as clean as possible. With the combination of damping and mass loading of the basket, there is a reduction in vibration that helps the lower midrange out some. Basically, there is less intermodulation distortion. The additional coherence trickles down to the midbass. Vibration is a loss of useable energy. Think about it. The driver is doing its thing, and energy is being expelled in the form of mechanical movement. Where do you want the energy to go? How do you want it to be used? Do you want the energy to move air, or metal and wood? To turn the Cornwall into a speaker that can do 100db with Rock music -- it needs the damping and additional mass loading on the lenses and basket, addtional bracing between the motorboard and back panel, and about 20 sheets of deflex. I don't know why PK didn't think this important. I think maybe part of it might have been his strong aversion to Rock music. There is a story in his biography about him picking up a new car. The radio station was tuned to a Rock station. He listened to a song, and after it was finished he pulled the car over, got into the trunk, pulled out a crowbar, and proceeded to rip the radio out of the dash. Well yeah, I guess if you listen to Jazz, Chamber music, and Classical -- you're not going to be too worried about what your speaker sounds like with Black Sabbath at 100db or more. You can all believe whatever you want, but I'm telling you the mods take the Cornwall from what I believe to be a very mediocre performer with Rock music -- into a speaker that can actually step into the ring with the RF-7. Quote Link to comment Share on other sites More sharing options...
Soundthought Posted April 13, 2003 Share Posted April 13, 2003 Dean, I like that story about Paul and his car radio. Classic. C&S, Ye of such little faith. Many of the things you mock are what make this hobby very interesting to me. I get my love for sound from playing Viola for 7 years and guitar for the last 5. My fascination with metal stems from my other passion...Bladesmithing. But most of all, the really interesting stuff has come by way of studying the concepts of particle physics and wave mechanics. That, too me, is the meat and potatoes of understanding most everything. It's fascinating, but one does really need to keep an open mind. We talk of snake oil, but yet scales are directional by nature. Go figure... John Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted April 14, 2003 Share Posted April 14, 2003 I might have been having a bit of fun with some absurdity there, but I will have you know I fully embraced and dug Dean's mod when he first explained it, also to a certain extent Alan's solid base mod. My Cornwall woofer frames are now fully covered with duct seal (caulk), also a bit on the horn. Furthermore I placed the Cornwalls on some solid stone mass rather than the carpeting which was absorbing some of the energy. I will get these hooked up again in the next few days and report back about what differences I hear. Maybe tomorrow morning. Not all my satire is meant to be detracting to the possibility that there may be validity in these improvements. I just happen to think the notion of break in time for caulk was a funny idea, so I worked it up for a moment. You should see the ton of caulking I applied to my Altec 511B horns! C&S, true believer. Quote Link to comment Share on other sites More sharing options...
Soundthought Posted April 14, 2003 Share Posted April 14, 2003 C&S, Right on. I haven't done any mods to my Klipsch, as of yet. Originality is the cornerstone of my collection. Now, if and when I get some Khorns, I'll be a modding fool. I have thought about getting some better acoustic foam for the interior of my RF7s, Chorus, and KSF 10.5s. Recently, I replaced the cheap foam in my SW12-II with a thicker, better foam. Hard to say if there is an audible improvement. It is a sub, after all. The difference may be more prevailent in the others. Time will tell. John. Quote Link to comment Share on other sites More sharing options...
fini Posted April 14, 2003 Share Posted April 14, 2003 C&S, Rough crowd for satire. Also, folks here can't see the eybrow thing, or that skipping deal you do, so they're not getting the full impact of your posts, as do all the neighbors (and your fans who tune into our local-access show). fini Quote Link to comment Share on other sites More sharing options...
Deang Posted April 14, 2003 Share Posted April 14, 2003 LOL Fini strikes again. I wouldn't mess with changing out the acoustic foam with another type of acoustic foam. I really think the way to go is with the Deflex panels. Quote Link to comment Share on other sites More sharing options...
Soundthought Posted April 14, 2003 Share Posted April 14, 2003 Deflex panels?!?!? What is this of which you speak? Quote Link to comment Share on other sites More sharing options...
dbflash Posted April 14, 2003 Share Posted April 14, 2003 Check out this site. Search for Deflex Panels. Took 8 panels to do my Cornwalls. I like the results that it gave the bass in my system. I am going to add them to my Heresy's. http://www.madisound.com/ Danny Quote Link to comment Share on other sites More sharing options...
Deang Posted April 14, 2003 Share Posted April 14, 2003 Quote Link to comment Share on other sites More sharing options...
horonzak Posted April 14, 2003 Share Posted April 14, 2003 DeanG Unplug your mids & tweets and do your tests and tell me what you hear plus show me your test results. You do Know how to test for this anomaly dont you? Quote Link to comment Share on other sites More sharing options...
Deang Posted April 14, 2003 Share Posted April 14, 2003 No, I don't. I wish I did. What are you saying? By unhooking the squawker and the tweeter I can more accurately hear any assumed changes to the woofer output? That's actually a pretty good idea. I bet that 15 incher sure sounds terrible playing at 90db all by its lonesome. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted April 15, 2003 Share Posted April 15, 2003 I am listening to my newly caulked Cornwalls. The woofer frame was fully covered and the horn was covered about 1/4 of the surface (or less), and the tweeter was untouched. I used duct seal. The Cornwalls were also placed on some solid concrete stones a couple of inches thick. There are also some heavy cabinets on top of the Cornwalls as well. Everything has moved toward more solidity. Results: (overall impression of the speakers as a whole) 1. bass response seems more tightly defined. It is a more dry sound making it easier to separate and decipher the exact pitch of the bass notes in the mix . 2. mid range is still bright but not painfully so at higher volumes as I believe it was before. This brightness is just the character of the Cornwall, but now it is not as unpleasant at higher volume levels. Flutes, trumpets, and voices are bright but good. I think the general characterisitc (as compared to my Altec system) is that the Cornwall woofer is just not quite as "present" as its great mid/high range response, so the sound is ever so slightly skewed toward the mids/high range. The woofer is certainly adequate, but compared to the Altec, just not quite as impressive, upfront, and sensuous, and I do not believe the Corns are tuned as low. (Altec system is tuned to 24hz) . The Cornwall system now is quite enjoyable, just not able to be as "big" as the Altec system I have built. The Cornwalls will certainly have a place in my listening routines and may be the speaker I use in various amplifier experiments and upgrades. {Craig is working up my HF-81 and I will report about that with the Cornwalls when I get them back.}. I will not always be wanting to fire up a tri amped tube system, so an alternate integrated tube system will fit in the program somewhere. 3. the overall impression is that the entire range of sound has this more "dry" quality, a better way to put it is that all the sounds are more separate and clear and distinct. At first I wasn't sure I liked this, but after listening to a variety of music, I am enjoying being able to pick out the parts more distinctly. This greatly bolsters the soundstage illusion as well. 4. compared to the Altec 416B which I have also been listening to lately, the Corwall woofer just does not have the strength of presence of the Altec, so this caulking has helped get a bit more out of the Cornwall woofer, not so much in volume but in definition and clarity which helps the equation. I am especially noticing this improvement when I am further away from the speakers (20ft) where I do a lot of listening when I am at the computer. Things seem to blend nicely at this distance with the Cornwalls (8' apart) towed in only very slightly, and at that listening distance the bass seems more integrated somehow, this must be the effect of my space. It is really very nice now and I can see why the Cornwalls are loved. The sound is good up close also, but with the volume lowered a bit. The distance away from them seems to blend the brightness of the horns and the elusiveness of the woofers so the combination is more integrated to my ears. {by "elusive" I mean they are just not so up-front, when you are right in front of them). 5. It does seem like a real improvement, I have no reason to want to tear all that caulking off and go back to the way it was before. In other words, it didn't hurt anything and most likely made a significant improvement. 6. This mod does make intuitive sense from the physical point of view, and I think Dean really came up with a good and accessible mod that I would also now recommend. The change will be more noticeable on certain recordings so try out a bunch. among ones I was using.... Mongo "Afro American Latin" Columbia/Legacy CD Monk, The Complete Riverside Recordings, Vinyl Orq. Sublime, on Bembe CD Billy Harper: "The Believer" vinyl vintage vinyl: Tito Puente: Cuban Carnival on RCA & Mamborama on Tico, Hank Mobley Quartet (wi/Horace Silver) Blue Note 5066. man ....these Cornwalls have arrived.....they are sounding great.... I can tell that the duct seal is really starting to break in...... and what he said: improved focus and control, sharper imaging, wider dynamics, and more natural sound....hey all this for $1.99/ pound duct seal at Yardbirds. Took about 6 or 7 pounds total at most...I got some left over for other projects.... ps. this test was using the components listed in the signature. C&S Quote Link to comment Share on other sites More sharing options...
Soundthought Posted April 15, 2003 Share Posted April 15, 2003 DbFlash & Dean, Thanks for the heads up on this product. It kinda looks like a turntable mat. I'm going to look into it. Quote Link to comment Share on other sites More sharing options...
Soundthought Posted April 15, 2003 Share Posted April 15, 2003 C&S, excellent review of performance differences. I imagine that caulking is one of those mods that a person should be absolutely sure about, prior to actually doing it. Removing it would seem to be a chore at best. Great test track selection. I see you have a 1200mkII. How do you like it? I've been using one for about 6 months and am very happy with it. Quote Link to comment Share on other sites More sharing options...
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