Pure Corn Posted February 22, 2005 Share Posted February 22, 2005 All, I would like some opinions on my planned CWII modifications. I've dreamed these up over the past month or so, and believe they will do some good. Cabinet: Remove the back. Reinforce the baffel (interior) with 3/4" birch plywood. Line the interior of the cabinet with felt. Remove the stock brace and replace it with two rectangular braces that touch all four interior sides of the cabinet. Create a new back that bolts to the outside back of the speaker, such that the interior dimensions do not change due to the baffel mod. Damp the horns with some Dynmat I found in one of the speakers. Replace the crossover components with higher quality parts. I also plan to make the crossovers EXTERNAL. This would insulate the components from vibration. I will also make the speakers bi or perhaps tri-wireable. Your comments will be appreciated, Orson Quote Link to comment Share on other sites More sharing options...
jwc Posted February 22, 2005 Share Posted February 22, 2005 I'm wondering why you would use wood for your bracing. Have you considered using a piece of steel between the mid and the woofer. Maybe something "L" shaped. That way less volume is used by your brace and the steel may be more "durable". Also, why not use steel for your "4 wall" bracing. I would agree with you on the crossover out side the box. You could create a little "house" for it. Why change the inside lining? Is yours bad? The back wood. Are you going to replace it with one thicker piece or are you going to add to it to make it thicker. Are you doing any grill mods? jc Quote Link to comment Share on other sites More sharing options...
Pure Corn Posted February 22, 2005 Author Share Posted February 22, 2005 ---------------- On 2/22/2005 8:09:37 PM jwcullison wrote: I'm wondering why you would use wood for your bracing. Have you considered using a piece of steel between the mid and the woofer. Maybe something "L" shaped. That way less volume is used by your brace and the steel may be more "durable". Also, why not use steel for your "4 wall" bracing. I would agree with you on the crossover out side the box. You could create a little "house" for it. Why change the inside lining? Is yours bad? The back wood. Are you going to replace it with one thicker piece or are you going to add to it to make it thicker. Are you doing any grill mods? jc ---------------- Funny you should mention steel. I considered it, but do not know enough to say whether or not it's the proper material. I would not use it for the baffle, because I'd be concerned about magnetic issues. Perhaps aluminum? I've just never seen a speaker with metal bracing, but can concieve of how it might work. The late model CWIIs have no stock interior lining. One of mine has some Dynamat haphazardly placed inside. The other is bare. The back will be one thicker piece; probably 1.5" MDF or birch plywood. No grill mods planned. Any suggestions? Quote Link to comment Share on other sites More sharing options...
jwc Posted February 22, 2005 Share Posted February 22, 2005 Well, I think getting new drill and make them black is what I plan to do. The "wood colored" cane grills are nice if you want the retro look. Check out the below two threads. http://forums.klipsch.com/idealbb/view.asp?topicID=51942&forumID=71&catID=19&search=1&searchstring=&sessionID={50E31BF4-618B-4432-BD6A-81806B99151C} http://forums.klipsch.com/idealbb/view.asp?topicID=61537&sessionID={50E31BF4-618B-4432-BD6A-81806B99151C} jc Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 22, 2005 Share Posted February 22, 2005 I had no way to compare the threads, but here's one where I was attempting to collect all the Forum members' Cornwall Modifications. The most common seem to be: stiffening the motor board with 'L' bracket, doubling the back with 3/4 ply mounted externally, dampening the mid horn with rope caulk or other material, and crossover modifications (see Bob Crites or DeanG) Here's that thread, apologize if its one of the ones listed above. Check SEARCH for Modificaitions for more. Michael http://forums.klipsch.com/idealbb/view.asp?topicID=51942&forumID=71&catID=19&search=1&searchstring=&sessionID={96D48E9B-3D47-4FCF-97CE-132EC3D491E4} Quote Link to comment Share on other sites More sharing options...
jwc Posted February 22, 2005 Share Posted February 22, 2005 Hey Colt, For some reason, I can't get that link to load. I agree with the l bracket idea btwn the mid and woof. What do you think about the bracing of the four sides of the interior walls? I just bought a CW1 off ebay. I want to do some moddin to this thing. I imagined puttins a "cross" of two metal brackets on the inerior for bracing. Seen anyone do something like this. What did you do to your corns. jc Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 22, 2005 Share Posted February 22, 2005 Go to SEARCH, type glossary, there are only two entries. one says Cornwall Mods Glossary. See if you can get in that way. I just brought it up. Never heard of anyone bracing the sidewalls, and I don't like the idea of playing with PWK's dampening materials in any way unless there is a moisture or mouse problem. I haven't done any yet but will be building a 5th Corn for center channel and reveneering all 5 along with rope caulk, L brace, xover repairs, double back panel at the same time. I'll probably just install some vibration dampening grommets when I reinstall the crossovers internally. Might be interested in a wiring mod that would let me actively BIAMP the two mains. Don't believe in bi-wire or passive biamp (whatever that is) It'll look like the Hope Factory floor in my garage when I get fired up! Michael Quote Link to comment Share on other sites More sharing options...
johnyholiday Posted February 23, 2005 Share Posted February 23, 2005 leave em alone=cost, or mod lightly Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted February 23, 2005 Share Posted February 23, 2005 You are certainly not getting the back panel off a late model Cornwall II because they DO NOT come off! You can only access the interior cabinet via the woofer hole when you remove it. The CII could use some bass linear acoustic panels installed to the entire interior of the cabinet. In addition, the crossover network in there looks cheap and cheezy and is certainly a candidate for rework. That being said I think the late mode CII is a fabulous sounding speaker bone stock and has extended HF range and detail over the previous Cornwall versions due to the K-57K and K-79K drivers. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 23, 2005 Share Posted February 23, 2005 Please note that althought the K57 may be a 'preferred' driver, that replacment diaphrams are NOT AVAILABLE for it already. One of the Steve's at Klipsch said he never saw one blown up. Figures that I would buy one from eBay that was inop. You could still brace the motor board by using the metal L bracket, just install with flat head machine bolts from the front and put nuts with nylon locking inserts in the inside. You wouldn't want them to come undone and rattle around. Does the CWII have different cabinet insulation? Why does everyone want to change it out? It was designed and tested that way for a purpose. You wouldn't restuff a RF7 box, would you? IS there some shortcoming to the CWII damping material? Michael Quote Link to comment Share on other sites More sharing options...
Pure Corn Posted February 23, 2005 Author Share Posted February 23, 2005 ---------------- On 2/23/2005 8:18:14 AM colterphoto1 wrote: Does the CWII have different cabinet insulation? Why does everyone want to change it out? It was designed and tested that way for a purpose. You wouldn't restuff a RF7 box, would you? IS there some shortcoming to the CWII damping material? Michael ---------------- The CWII has NO cabinet insulation in stock form. Quote Link to comment Share on other sites More sharing options...
Pure Corn Posted February 23, 2005 Author Share Posted February 23, 2005 ---------------- On 2/23/2005 7:46:19 AM Frzninvt wrote: You are certainly not getting the back panel off a late model Cornwall II because they DO NOT come off! You can only access the interior cabinet via the woofer hole when you remove it. ---------------- No offense meant, but are you certain? I've looked inside and out, and believe that it can be "jigsawed" off without damaging the cabinet. The back is an individual piece that is glued to blocks mounted to the interior of the cabinet. Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted February 23, 2005 Share Posted February 23, 2005 The CII's motorboard is also already interally braced by a nice strong piece of wood that runs front to back, no bracing should be necessary, damping the horns is a moot point as well since they are made of composite material. Get some acoustic panels from Bass Linear or Parts Express and cut and secure them with some Scotch 77 Spray Adhesive and rework the crossovers then just sit back and enjoy! This can easily be done through the woofer hole, I know I did it! Why in the world would you want to jigsaw the back of the cabinet off? You are going to jeapordize the integrity of the cabinet if you do that. In addition, it may be notched into the side walls. You have nothing to gain whatsoever by doing this! Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 23, 2005 Share Posted February 23, 2005 NO damping material- that's just not right. SHould have damping on one of each pair of paralled sides generally speaking. So you'd pad one side, top of shelf ledge (not inside the port) and the back of the cabinet. Egg-crate foam maybe, you're just trying to break up the standing LF waves. Michael Quote Link to comment Share on other sites More sharing options...
dodger Posted February 23, 2005 Share Posted February 23, 2005 If you decide to remove the woofer, 1x2s or 1x3s can be cut and then fit to sides, top, bottom and back. I would recommend against using metal until speaking with someone with great knowledge of the possible inter-actions. If you want to damp the sides mask off all drivers, horns and crossover. Dyna-mat makes a spray product. Smells, but that goes away. New bracing attach with liquid nails, leave stock alone. You can cut a hole before spraying to allow the crossover wires to come through, but then seal tightly. Quote Link to comment Share on other sites More sharing options...
Pure Corn Posted February 23, 2005 Author Share Posted February 23, 2005 ---------------- On 2/23/2005 10:21:51 AM Frzninvt wrote: The CII's motorboard is also already interally braced by a nice strong piece of wood that runs front to back, no bracing should be necessary, damping the horns is a moot point as well since they are made of composite material. Get some acoustic panels from Bass Linear or Parts Express and cut and secure them with some Scotch 77 Spray Adhesive and rework the crossovers then just sit back and enjoy! This can easily be done through the woofer hole, I know I did it! Why in the world would you want to jigsaw the back of the cabinet off? You are going to jeapordize the integrity of the cabinet if you do that. In addition, it may be notched into the side walls. You have nothing to gain whatsoever by doing this! ---------------- Thanks. When you mention reworking the crossovers, do you mean design a new network or just replace the cheap components? The idea behind removing the back is to thicken the baffle. In the end, it would be 1.5" thick rather than the stock .75". Most high-end designs I've read about have thicker baffles. A new back would then be built that bolts on the outside of the cabinet, which would preserve the original volume. Maybe it would be better to just build custom cabinets... Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted February 23, 2005 Share Posted February 23, 2005 Have you seen the crossovers in there? They do not even have a terminal strip they are all wired to a piece of metal hammered into the wood. I would upgrade all the caps and wiring to the drivers. Why not just add a piece of HDF to the current back and relocate the input cup onto it, it would be the same thing. It is not going to make much of a difference though and really not worth the effort. Acoustic Panels and Crossover component updates is all you really need. Actually they sound great as they are. Quote Link to comment Share on other sites More sharing options...
Gilbert Posted February 23, 2005 Share Posted February 23, 2005 I've been around this block a few times on this subject. I finally had it with the old tissue, toilet paper like insulation in my older Cornwalls. This stuff is good. Very good. http://www.basslinear.com/ I've installed it in 6 cornwalls, and it's easy to work with, and you will hear the difference. The problem with the later cornwalls, as you undoubtedly have already found out is acess. Your limited by the woofer opening. But with patience and care, you could install this stuff. It is a very good product. Quote Link to comment Share on other sites More sharing options...
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