Deang Posted February 21, 2003 Share Posted February 21, 2003 Gently tapping around inside the cabinet on the parts revealed some surprises. The squawker lens, generally speaking, doesn't really resonate all that much while it is securely attached to the baffle. It resonates a little, but nothing that I believe would contribute to a degradation in sound. Once removed however, tapping it with the back side of the fingernail makes a nice ringing sound. Since I had them removed, I went ahead and sprayed them down with a 1/16" of "Road Kill" acoustic damping spray. If anything -- they certainly look better now. The "demon" in the box is the stamped woofer basket. It's bad. Very bad. Playing the speaker with the back off, with a stand-offish ear -- shows what I believe to be the major problem regarding the loss of coherency at higher SPL's. It's not the squawker that's falling apart -- it's the lower midrange/upper midbass. Damping the basket got me another 10db of clean bass. The Northcreek wire is a winner. Removing the lamp cord wire and replacing it with the silver coated copper results in substantial lessoning of grain in the treble. Late last night I started experimenting with a minimal amount of damping in the box itself. Currently. I have thin pillow on the lower shelf area adjacent to the ports. The ports are NOT blocked. So far, I really believe this is helping the woofer out some. The bass doesn't appear to be as loose, and I think there is a little bit more control going on here. I also found out that playing the Cornwalls with the backs removed -- nets a very good sound as well. I don't quite know what to make of this yet. Sitting them a foot from the back wall with the backs off creates a chest pounding experience. Still playing. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2003 Author Share Posted February 21, 2003 ! Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2003 Share Posted February 21, 2003 Try doing the Roger Floth article in that website I did. Of the mods, the only one I would consider is strengthening the back of the cabinet. As for your grain in the treble, that is absolutely what I like the best about the Cornwall with my 2A3 amps. There is almost NO GRAIN in the treble, but this is revealed more in quality recordings. I personally also agree with your assessment of the mid horn, especially in the smaller horn via the CW (the Khorn mid is much larger). The reason why it sounds better with your back off is that you are turning it up so high and with something like the Stone Temple Pilots, the back on is causing problems revealed. I still think this is not the speaker for recordings like the Stone Temple Pilots CORE. http://home.earthlink.net/~ivol/klipsch_cornwall/cornwall_mod.htm kh Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted February 21, 2003 Share Posted February 21, 2003 Very intriging...keep us posted on the latest discoveries! Please send more pictures when available...thanks! Stupid question time...When you sprayed down the midrange horns with a 1/16" of "Road Kill" acoustic dampening spray, where exactly did you spray them? On all four sides "inside" the horn flare, and how far back? Not to the driver itself? And do you spray all four corners outside the horn? Not the magnet, right? Where do you purchase "Road Kill" or its equivelant? Is that rope caulk on the outside of the woofer basket? Are they single strands of rope per basket brace, or double? I assume the "Northcreek" wire used is the blue and yellow wire? Looks like you replace every single wire inside the cabinet, from the inside back panel to the crossover to all the drivers? I'm stupid when it comes to technical issues, so I gotta make sure! Do you use dampening material similar to what Klipsch uses, or "Dynamat" car audio insulation? Interesting to hear that with the back panels off and a foot from the back wall, the overall sound is improved...should be an interesting experiment. Sorry for all the dumb questions, but I never said I was too bright, especially when it comes to mods! Keep up the good work! Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2003 Share Posted February 21, 2003 Lets just quickly say i KNOW FOR A FACT that ole Dean didnt spray the INSIDE of the horns! If he did, I would personally go to his abode and beat him with the closest heavy object lying about. Even ole STP Dean is not that far gone! heh... Yeah, the CW woofer basket is surely not a cast aluminum affair, rigid like a Huntington Beach pier piling! It's a stamped mess. But the CW does well despite this. But I am sure improvements can be wrought with work here. But that aint the CORE problem, knowhatimsayin? heh... kh Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2003 Share Posted February 21, 2003 Indeed, this is true, but not the cause of the harshness he is reporting. It will help in low end clarity at high volume, however (as well as bracing the cabinet rear). BTW, just to get an idea of what Dean is listening to at very high levels, go here and sample Stone Temple Pilots CORE. Although I have a host of Indie material, some of it really heavy and aggressive, I dont think this recording would ever sound too red hot via the Cornwalls. OF course, mods will help a bit, but to me, this is just not the typical Heritage forte. Scroll down and listen to STP's CORE samples in Media Player NOTE: This is a mono, low bit sample that is no where near the quality. It is just for representation. There are places online to get the full files... kh Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2003 Author Share Posted February 21, 2003 LOL. Man, talk about setting me up:) That sounds awful. People are going to think I'm half deaf. Like I told you in the email, I use material like this to torture test a speaker. If they get through this CD without putting me in the fetal position -- they pass the test. Cuts off this particular CD that I enjoy are: Sex Type Thing, Piece of Pie, Plush, Crackerman, and Where the River Goes. Playing these cuts last night revealed that I had totally transformed the Cornwalls. ALL wire was replaced, with the only exception of course being the wires coming off of the transformers. I also soldered my connections behind the terminal blocks. Lenses were sprayed with drivers attached. I used Saran Wrap around the driver, tightly wrapping it and tucking it between where the driver meets the edge of the lens flange. I then used thin medical tape to tighten everything up, to make sure nothing got on the driver. I only sprayed the outside, avoiding the front flat edges as to avoid getting ANYTHING in the front of the horn -- which I stuffed with tissue paper all the way to the bug screen covering the driver elements. Now, let's not get carried away here. LOUD for me is 95 db. I rarely go beyond this. However, a good speaker should sound very good at least to this point. I'm easily getting this now. 100 db is a little intense, but swinging the speakers so I am not on axis works very well here. If you want to do Rock-n-Roll on the Cornwalls at realistic levels -- these mods are a must. Trust me, they're still Heritage all the way. Shoring things only allows them to go the distance, maintaining the same signature they have at the lower SPL's. I'm listening to Alice Cooper's 'Dragontown' right now. It might take a squad of Stormtroopers to get me to reinstall the back panels. Unbelievably tight, controlled bass with the backs off. Anyone have any idea how much low frequency response I'm losing with the backs off? Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2003 Share Posted February 21, 2003 Deano, did you see the article I linked to? Why not try to strengthen the back panel? IT cant hurt and can still be left off. The flex of the back panel at high volumes is causing you problems I bet. It's a simple mod. kh Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2003 Author Share Posted February 21, 2003 Agreed. The only thing an old Cornwall needs for Rock-n-Roll is a little damping on the woofer, new wire, and some additional bracing. Making my way through the article now. I don't think damping the squawker does sh!t. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2003 Author Share Posted February 21, 2003 No wonder it sounds so tight. What about with the rear panels attached, with some marginal fill in the area leading to the ports? Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2003 Share Posted February 21, 2003 What about bracing? Again, this appears to be the answer more than fill. Also, when you change the volume of the interior, other parameters are affected. The Cornwalls volume is pretty spot on with models taken of a reflex speaker of this nature. kh Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2003 Author Share Posted February 21, 2003 I understand the issue with the additional bracing -- I'm not avoiding that. I was just curious about the fill factor. You answered my question on that one -- thanks. Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted February 21, 2003 Share Posted February 21, 2003 Kelly keeps mentioning bracing so I'll ask a question. The backs on my heresies are only 1/2" plywood where the rest of the cabinet is 3/4". Would a stiffer back on the heresy be worth trying?? It seems to me that it would, I could make a replacement back and just swap one and do a left right comparison with the balance knob. Any thoughts? Peace, Josh Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2003 Share Posted February 21, 2003 See the article for the problems Floth encountered when changing the area. Suddenly, Mr. Crossover needs tweaking etc. What a nightmare. Marks point of brining in other variables starts to weigh in here too. Pretty soon you have a DEANO CORNPOON Mk III. Heh.... Well, perhaps that is a bit over the top. But hell, it's Friday and I am over my posting limit! kh Quote Link to comment Share on other sites More sharing options...
Allan Songer Posted February 21, 2003 Share Posted February 21, 2003 Here I go again with the BEST mod I have ever tried with the Cornwall, something that tightens up the bass considerably. You need to put the Conrwalls on a really, really heavy and DENSE base. If yours have the factory risers, REMOVE them and make copies of them that are enclosed on both sides by 1/8" or 3/16" sheet metal--use SEVERAL wood screws and silicone to seal the metal to the wooden riser which you FILL with sand. I use cones and cups on my raised hardwood floors, but you might want to experiment if your floors are concrete. I have uses blutad between the stand and the speaker and don't hear much difference with or without. This is a cheap, incredibly effective tweak--BELIEVE ME. I have owned my Cornwalls for a couple of decades now and have had them on these stands for the last 5 or 6 years. Quote Link to comment Share on other sites More sharing options...
edster00 Posted February 21, 2003 Share Posted February 21, 2003 I made bases for my Cornwalls also. Mine were constructed of 2x4's and 1/2" plywood...sealed, sand filled and stained to match the Cornwalls. It did help tighten the bass IMHO. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 22, 2003 Share Posted February 22, 2003 What is the physics behind the claim that putting sand under the Cornwall is going to enhance the bass response. I am not about to tear up my mint vintage Cornwalls unless I understand the physics behind this claim. If I understood the physics, if there is any, then I might design my own mod to create the equivalent effect without doing anything to the Cornwalls I do not wish to do. What is the physics? How do you explain the effect of what you did and why does it have this effect? C&S Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 22, 2003 Share Posted February 22, 2003 This is ALL OVER THE NET...in many articles. I mean there are pages in print articles, magazines, on the net, in the forums, etc. And the physics are not hard to understand at all. I think this has been gone over countless times in so many articles with speakers stands, spiking, etc. Look at speaker manufacturers that call for lead and shot filled, spiked stands (90% of the monitors call for stands). Look at the many, many speakers made with enclosures for deadening and sand and shot. Looks at the spikes offered with most floorstanding speakers. Look at the many articles about suspended wooden floors vs CONCRETE FLOORS and the differences. It's actually a valid point and an idea that is basically been in the mainstream for a long time in various forms. Some of it involves carrying over some of the ideas you learned from isolation/and or coupling with stands over to other media. Think about mass and vibration linked with pinpoints to a solid, deadened, inert, vibration free base, in turn, attached to the floor via spikes or cones (and even better if floor is inert). Think about what are some of the ways to tighten bass and imaging apart from speaker placement. A lot of these points intertwine. Ironically enough, however, I didnt like the sound of spiking my Cornwalls to my floor, but this is literally the only speaker I have owned that I felt this way (and I didnt enclose and sand/lead shot fill my riser). Of course, you could always ignore this tip and save yourself the headache of the research and time to build the mod. kh Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 22, 2003 Share Posted February 22, 2003 How about an actual link to a site which mentions specifically the building of a sand filled riser directly under the bottom of a speaker cabinet like the Cornwall? The spikes do not interest me, the stock riser on my Cornwalls seems to work just fine. It is interesting that you don't use the "sand filled" (or equivalent) mod, or do you? It is interesting that Songer's one most dramatic tweak for bass improvement to the Cornwall is not of such universal result as to have appealed to your situation. Do your Corns rest on hard floor or carpet? I am thinking of simply placing my Corns with stock riser on a marble slab instead of the carpet to see if there is a difference. Actually my Cornwalls have been sounding very very nice lately anyway with the Music Hall-Paragon with Telefunkens-Triode E34s Mullards Class A. I am inclined to leave them be, except I will be doing some shuffling around and I have access to the marble slabs. C&S Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 22, 2003 Share Posted February 22, 2003 Might putting more weight on top of the speaker cabinet do the same thing as having it rest on a sand filled mass? I think someone else here mentioned that the best tweak he had accomplished was indeed bolting the speaker cabinet to the wall. If I understand this physics, as you so clearly explain, the idea is to keep the cabinet from "moving"? C&S Quote Link to comment Share on other sites More sharing options...
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