gearhead919 Posted May 31, 2012 Share Posted May 31, 2012 Hey guys, first post on here. new to the scene. Found a pair of KP250II's at a garage sale($35). One woofer was trashed and the boxes were lookin pretty rough as well so my intent was to just buy a new woofer, yank out all the parts and build new heresy cabinets. Until one day, when I was looking at my dad's cornwalls sitting in the living room and thought, "well hey most of the parts are the same why not build some cornwalls instead(prices for new 12" woofers vs 15" don't seem to be terribly different. Found a sketch for a cornwall cabinet over here: http://forums.klipsch.com/forums/t/105447.aspx . After that I downloaded google sketchup and drew up my cornwalls. Hope this project works out well! gearhead Quote Link to comment Share on other sites More sharing options...
ricktate Posted June 1, 2012 Share Posted June 1, 2012 The parts are not the same but you could do it ...wont be as good as a Cornwall ....maybe someone else could give more information for you. Rick Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 1, 2012 Author Share Posted June 1, 2012 The parts are not the same but you could do it ...wont be as good as a Cornwall ....maybe someone else could give more information for you. Rick Rick, I realize that in the exact sameness of the parts that they are quite different, Im sorry that I mis-spoke. I do think that they are quite similar in the respect that they are horn loaded mids and highs and when I listen to both the cornwalls and the kp250II's they produce excellent sound. How much will moving the horns from a small to a large cabinet change the sound? It should be none because of the fact that they are horn loaded right? As far as the woofer is concerned, if I buy say crites CW1526C replacement woofers and put them in the very enclosure they were designed to be in how much more inferior can that sound? Which I guess leaves the crossovers. Im not an electrician by any stretch of the imagination, but I have a basic understanding of how a crossover works. It basically controls at what freq the drivers stops playing and how fast it stops playing it (rolloff) right? In which case, it may play up slightly higher than a cornwall II but again I am wondering if any of this will truly be discernable to the human ear or if it will just sound like another pair of rockin klipsch? Quote Link to comment Share on other sites More sharing options...
willland Posted June 2, 2012 Share Posted June 2, 2012 Gearhead919, Welcome to the forum. I think what you are trying to do is adventurous but doable. I am a simple guy so I would just buy Cornwalls.[] There are many well informed members on this forum that construct DIY projects all the time. Hang tight a little longer and you will get many suggestions from the ones in the know. Where are you located? Maybe a Klipsch DIYer lives nearby and would give you some pointers or even help with your "Franken KP-Cornwall". Bill Quote Link to comment Share on other sites More sharing options...
DizRotus Posted June 2, 2012 Share Posted June 2, 2012 It's kind of like the parable about "stone soup." The only Heresy parts that are also in a Cornwall are the tweeter and the squawker driver. You'll need new squawker horns, new woofers, new balancing networks and new enclosures to end up with "Cornwalls." Enjoy the project. Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 2, 2012 Share Posted June 2, 2012 Here are drawings for the 2 port and 3 port Cornwalls, drawn by Jim Easley (I think... ). The newer Cornwall III has changes not on these drawings (woofer moved higher on the motorboard for one thing). These will get you to the correct vintage style. AND... notes from Andy on the 77 specs (2 port): Internal measurements for 1977 Cornwalls type CWO. 1. internal width: 23 7/8" 2. internal length: 34 1/4" 3. internal depth: 13 1/2" 4. port: 9 1/2" x 22 3/8" x 3 1/8" 5. port holes in motorboard: 10 1/2" x 2 3/16" 6. motorboard inset: 5/8" 7. back: flush Notes: -cabinet depth from INSIDE of back to INSIDE of front -depth of port measured from BACK of motorboard -sides of port are two 3/4" plywood pieces = 9 1/2" -port + cabinet measurements are INTERNAL dimensions -port slots in motorboard has 7/8" wide middle divider -port slots also leave a 7/8" band along bottom edge -port slots not quite flush with top port edge 3/32" -all panels 3/4" (3/4" designated ply is actually less) -cabinet lined with 5/8" insulation, unknown material -all measurement done at least twice Hope this helps, Andy Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 2, 2012 Share Posted June 2, 2012 The three port... Quote Link to comment Share on other sites More sharing options...
garyeanderson Posted June 2, 2012 Share Posted June 2, 2012 The original topic that JimE started is worth a read and there are others too that I would (and did read several times) before starting any cornwall clone build. JimE topic is OK Let's Start a Cornwall Drawing http://forums.klipsch.com/forums/t/50919.aspx?PageIndex=1 Cornwall Mods Glossary http://forums.klipsch.com/forums/p/43238/404703.aspx#404703 I think I spent about a month reading every topic that deals with the Cornwall and the mods that folks on this forum have done before I started building and drew out numerous versions before settling on these. Its just a bass bin for the 15 inch K33 woofer and the highs are handled by other external horns Meet Cornzilla http://forums.klipsch.com/forums/p/147639/1519463.aspx#1519463 If I do another pair I have drawn up a Cornwall Slant Monitor to try, I havn't looked at a build since January, it seems to make a good winter project for me... Cornwall slant monitor? Yes it snowed last night http://forums.klipsch.com/forums/p/158483/1674880.aspx#1674880 In any event it is a fair amount of work to build any speaker just to see what it's all about. Many people on this forum inspired me and I would like to do the same. Buying is easy, building is fun! Build what you want and have good time doing it... Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 2, 2012 Author Share Posted June 2, 2012 Bill, Thanks for throwin out the welcome mat! I'm glad you think my project is doable. I'll give you a little background so you can understand why I might want to do such a thing. First of all, I'm 22yrs old and located in Rapid City, SD. I am a contractor but there is basically nothing I won't attempt to build/fix/modify/restore. I have restored things such as 100 year old timber boring machines, hand planes, bicycles, motorcycles, houses, vehicles, you name it. Because I like to be a "jack of all trades, master of none" there are definitely things that I don't know and thus I must make things up as I go . As far as my history with klipsch speakers are concerned, I grew up with my folks in a house with Klipschorns and then Cornwalls, my dad is a drummer as am I and it's safe to say I've listened to lots of klipsch sound for some years now. For me, the reasoning behind doing this project is because I saw a sorry looking pair of KP250II's that needed rescuing. My ultimate goal is not to make an exact Cornwall, but rather an upgraded version of the KP250II. I'm calling it a cornwall, because if it looks like a Cornwall and sounds like a cornwall (hopefully close) then it's close enough to call it one in my book. For me the act of building or restoring something takes it from an object into a memory, something I can keep and take care of forever, and one day look back on it and remember the work I put into building the speakers. Again thanks for rolling out the welcome mat! I hope I can get some good information and people can learn from my mistakes here. Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 2, 2012 Author Share Posted June 2, 2012 The original topic that JimE started is worth a read and there are others too that I would (and did read several times) before starting any cornwall clone build. JimE topic is OK Let's Start a Cornwall Drawing http://forums.klipsch.com/forums/t/50919.aspx?PageIndex=1 Gary, Thanks for the suggestion! I actually have read (skimmed) through that thread and that is the exact drawing I used to generate a CAD drawing of the speakers I intend to build. I would love to upload the Google Sketchup (free) file on here but it says that this forum does not support that file extension (.skp) if anyone knows how to upload one of those please help a noob out! thanks I'll include a few pics from sketchup so everyone can see the inside and what not. Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 2, 2012 Author Share Posted June 2, 2012 It's kind of like the parable about "stone soup." The only Heresy parts that are also in a Cornwall are the tweeter and the squawker driver. You'll need new squawker horns, new woofers, new balancing networks and new enclosures to end up with "Cornwalls." Enjoy the project. Diz, I want to thank you for your kind words! As near as I can tell the man in the stone soup parable was a complete genius. Thanks for making the connection [] If I wanted to have EXACT cornwalls, yes, I would definitely end up replacing almost everything. I do not, however, wish to have EXACT cornwalls. I was at a garage sale and rescued a pair of KP250II's for 35 bucks. One woofer was trashed (If anyone needs a 12 inch woofer from the other one, holler and i'll sell it to ya cheap!) and the cabinets were utterly disgusting. So I already am having to build new cabinets and replace a woofer. Which is when I decided to build bigger cabinets and buy bigger woofers (almost the same price). The original tweeters and squawkers sound great so why mess with a good thing? Crossover works great, The KP2.5D starts rolling off the mids at 700hz which may be a little higher or lower (I dont actually know where the crossover points of the cornwalls start/stop) than the cornwalls but how much of a difference can that truly make? They wont be exact cornwalls, but I'm quite confident they will produce goosebumps just the same. Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 2, 2012 Author Share Posted June 2, 2012 Thanks! these were actually the exact drawings I used. Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 2, 2012 Author Share Posted June 2, 2012 Motorboard behind front trim Quote Link to comment Share on other sites More sharing options...
gearhead919 Posted June 2, 2012 Author Share Posted June 2, 2012 Green=corner bracing/port. Right side and back removed Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 2, 2012 Share Posted June 2, 2012 Does the KP-250 II use the same parts as the Heresy II (except maybe the woofer). If so, you could beuild some Tangent 400 cabinets, as they use the same components. The larger ported cab with the 12 inch woofer goes lower. Still a mort verticle cabinet, and will make it easier to place. FREQUENCY RESPONSE: 38Hz-20kHz(+-)3dB Bruce ps Nice drawings btw, and welcome to the forums. Quote Link to comment Share on other sites More sharing options...
djk Posted June 3, 2012 Share Posted June 3, 2012 +1 Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted June 4, 2012 Moderators Share Posted June 4, 2012 Welcome Another option............You would not need to go this big if space was a problem, this was done by a forum member for his garage, CECAA850 is his name. http://community.klipsch.com/forums/t/129471.aspx?PageIndex=1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.