IB Slammin Posted April 10, 2004 Share Posted April 10, 2004 Has anyone removed a Cornwall motor-board? How difficult? Is it glued? Andy HDBR? Anyone? Thanks, Terry Quote Link to comment Share on other sites More sharing options...
Dflip Posted April 10, 2004 Share Posted April 10, 2004 I think I just removed the parts when I replaced everything on mine. First went the inductors, then the capacitors and later the wiring. They are screwed down and can be unscrewed fairly easily. It would be easier to do it that way, but back then I just wanted to replace the old parts with newer ones, since I was having some sound problems at the time. Copy "Hyde banished -- transforming the Cornwall" into the Search window or at least the first two words and it will take you to the posting. This was originally posted by Dean. Don Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted April 11, 2004 Share Posted April 11, 2004 The method for securing the motorboard is dependent upon WHEN your Cornwalls were built. Tell me that and I can answer your question. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted April 11, 2004 Author Share Posted April 11, 2004 Andy, They are 1975 oiled walnut. Thanks for the help. Hope to see you in LR on the 8th. Regards, Terry Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted April 11, 2004 Share Posted April 11, 2004 First off...why are you wanting to remove the motorboards? IOW...is this ABSOLUTELY necessary for some reason? The motorboards on yours were installed using a glue bead and a combination of 1-1/8" staples and/or 1-1/2" finish nails. Glue blocks are installed in the cabinet around the front perimeter about 1-1/4" in from the front edge. These blocks are glued and stapled into the inside of the cabinet. The shelf supports for the port baffle are also glued and stapled into the lower sides of the cabinet...then the shelf is glued and stapled to these blocks. Then, the cabinet is laid on its back, glue is laid on all edges that will contact the motorboard (front edges of blocks, shelf supports and shelf itself), then the motorboard is dropped in and stapled and/or nailed THRU the motorboard into these glued surfaces under the motorboard. WARNING: Removal of the motorborard MAY seriously damage the interior sides of the cabinet panels, MAY destroy the glue blocks used to secure the motorboard to those panels, MAY cause separation of plys or serious damage to the motorboard itself, and/or MAY cause serious structural damage to the cabinet itself. It is recommended to NOT REMOVE the motorboard unless it is absolutely necessary to do so! Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted April 11, 2004 Author Share Posted April 11, 2004 Andy, I suspected as much. I wanted to replace the motor- boards, not just remove them. Damage to the boards would be OK, but if they are glued, I could risk destroying the cabinet in the process. Humm. I can see getting half way through the project, making a big mess, regretting the whole thing and not being able to go back. Why do I want to do it? I have replaced the stock mid-range with Altec 511b/902-16A horns and drivers. At this time, the K-77s are bolted to the top of the 511s and both are perched atop the box. WAF will require that the horns be boxed at some point. I have nasty "plugs" screwed to the inside of the motor-board covering the mid/tweet penetrations and wanted to replace the fronts with solid plywood. New motor-boards would produce a more solid front plane and lend themselves to additional bracing. During critical listening sessions, the grills are off and '75s look dreadful. Sounds like I could be opening a can of worms. Does knowing that I intend to sacrifice the orginal front boards make this project sound more realistic? I will always keep my '73 verts orginal, but will never go back in the '75s. A vast majority of the things we don't like about CWs are cured with this mod. The mids are unbelievable. Smooth, sweet, alive, improved sound stage and the "sweet spot" is everywhere. The "chew on your pant leg" CW midrange is only a memory now. Thinks for the help. Terry Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 12, 2004 Share Posted April 12, 2004 Why not build new cornwall boxes?? I would think that this would be much faster, and you can finish them or have them finished for you by a cabinet shop. You would have to build a new motorboard anyway, there are only 5 more sides to go. If your cabinets are in nice shape, you may consider selling them empty to recoup some of the cost of building new boxes. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted April 12, 2004 Author Share Posted April 12, 2004 ---------------- On 4/12/2004 12:35:52 AM michael hurd wrote: Why not build new cornwall boxes?? I would think that this would be much faster, and you can finish them or have them finished for you by a cabinet shop. You would have to build a new motorboard anyway, there are only 5 more sides to go. If your cabinets are in nice shape, you may consider selling them empty to recoup some of the cost of building new boxes. ---------------- Mike, Building new cabs might be the thing to do..... Terry Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted April 15, 2004 Share Posted April 15, 2004 Terry, That's a pretty creative mod. I suppose the size of the Altec mid horn will require placing the woofer lower on the motorboard? Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted April 15, 2004 Share Posted April 15, 2004 Could a K-500/K-505 horn (used in the Belle Klipsch) be used in the Cornwall for more dispersion, the cutoff frequency is determined by the crossover and not the horn lens correct? I suppose if this was a good idea PWK may have already tried it. Any thoughts? Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted April 15, 2004 Share Posted April 15, 2004 DaddyDee, If you try to lower the woofer position on a Cornwall you hit the shelf of the port with the flange of the driver, so that ain't a good thing! Frxninvt, The horn lens of the BK won't fit in the Cornwall cabinet...it is too deep of a horn lens for the depth of the cabinet. The stock mid horn lens, with the K55V attached is almost touching the back of the cabinet to begin with! Besides, the BK's horn lens was a compromise design to try to get the performance of a LaScala out of that cabinet even though it was not deep enough a cabinet design to allow for the use of a K-400 horn lens, without the K-400's driver sticking out the rear of the upper cabinet section. The BK was a complete compromise design...basically a redesign of the LaScala for aesthetic considerations, which led to concessions in performance being made for the aesthetics of the B/K cabinet. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted April 15, 2004 Author Share Posted April 15, 2004 Dee, the woofer location is where it needs to be. The reason to replace the M/B is aesthetic. WAF -The plugs covering the mid/tweeter holes look pretty bad. Frz, The K-500 with a K55V would be a step in the wrong direction. (Backwards) The 511's, K-500, and K-400 all hang over the back of the box. I intend to put the top end in a seperate cabinet at some point. (WAF again) I kind of like the looks as is. Ha Regards, Terry Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted April 15, 2004 Share Posted April 15, 2004 Thanks HDBR Terry, yep. Ich verstehen Quote Link to comment Share on other sites More sharing options...
HornEd Posted April 15, 2004 Share Posted April 15, 2004 HDBRbuilder... I thought by now you would be "Klipsching" from Kabul or maybe Baghdad... especially Baghdad-by-the-Bay... a Herb Caen euphemism for San Francisco. Where ever you may roam... stay in touch. Andy, you bring a dimension to this Forum like now one else has been able to do. Thanks from all you have inspired... until you are better paid! -HornEd Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted April 16, 2004 Share Posted April 16, 2004 HornEd, I found out yesterday that I will NOT be getting called up in May after all. Actually, that is both a good and bad thing. Good in that I am just finishing up Phase I of my MOS transition Course, Phase II is scheduled for two weeks late this summer. I will be going from an 11B/11C (Infantry or Mortars) to a 42A (Personnel Services Sergeant). At 51 years of age they now think I can best serve by sitting at a puter and taking care of the troops that way, instead of being a grunt. The bad part is that it left me hanging yet again with no job prospects at the moment. I had already started packing stuff up and putting it into storage for this and had turned back two job offers because I was told this was gonna happen "for sure" this time. So, here I am...wondering what the hello I am gonna do again. Hopefully I will be able to find something soon. This crapola is really beginning to get on my nerves! LOL! The weirdest part about it all is that I would likely best be able to use my abilities by training troops at Ft. Benning in Mortars, or in MOUT training, since I am a certified instructor for both of those and that is what they NEED training in right now....particularly in MOUT operations. BTW, MOUT=Military Operations in Urban Terrain. Time will tell. WHo knows?...they may not call me up at all this time around! Quote Link to comment Share on other sites More sharing options...
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