Tin Turtle Posted December 4, 2012 Share Posted December 4, 2012 I had a thread going on another forum but I really wasn't getting much feed back so I thought I would replicate it over here. Hope this is the right place for it. I am excited to see what these will sound like when I am done. Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 4, 2012 Author Share Posted December 4, 2012 My JBL's lost the foam surrounds last year and I had them rebuilt, plus paid to upgrade the crossovers. After about 6 months of use they died. Weird, both of them lost the woofers at almost the same time. Anyway, I decided it was time for a change. I have never owned horns and I've often wondered about Klipsch, so I looked into a couple of pair. I also looked at Zaph's 12.3 and was almost ready to start cutting the cabinets when I went off on a tangent and ended up with Cornscala's instead. I wanted to modify the design some to allow for a split cabinet. After talking to Bob Crites on the phone he gave me some ideas and I went back to draw some more. I loaded everything into CutList and checked design for precuts at the yard and for an idea how much these things would cost. Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 4, 2012 Author Share Posted December 4, 2012 I struggled with whether or not to build a set of prototypes from MDF. I had a friend who wanted a pair, but in the end I wanted them quick so I went off the deep end and milled the real stuff first. I wanted to pay homage to the Klipsch heritage, but I could not stomach bare edged plywood. Since I build guitar cabinets I relate to resonance, and in fact I mill my solid wood cabs to 5/8" to cater to it. But for me, I want my hifi cabs to be MDF. All of the internal parts are MDF, motor board is MDF and some external parts are raw MDF. For cabinetry I took a while to think about what I wanted. I decided I wanted the **** joints similar to the old Klipsch, but with edge banding. There were some options in veneer core ply, but I chose A1 cherry over 3/4 MDF. With a little design tweaking I kept it down to 2 sheets of cherry, and 2 sheets of 3/4 MDF. Total for wood was $260. I chopped up the raw MDF parts first, and then went to the lumber yard and picked up 2 sheets of cherry. Pulled them onto my workbench and started the rough breakdown, then final dimensions on the table saw. http://www.tinturtle.com/image.axd?picture=2012%2f11%2fpaneltable.jpg http://www.tinturtle.com/image.axd?picture=2012%2f11%2fpanels.jpg Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 4, 2012 Author Share Posted December 4, 2012 I use a Festool Domino for my quick and dirty joinery. I still have a biscuit joiner, and I use it when I need something sloppy and moveable, but the Domino rules for strength and precision. All MDF faces get a double coat of Titebond III, mortises are filled and 8x40MM dominos are used. Clamped under pressure for 4 hours each. You really only need 2, but there was other things to do anyway, so why not. http://www.tinturtle.com/image.axd?picture=2012%2f11%2fpanel_domino.jpg http://www.tinturtle.com/image.axd?picture=2012%2f11%2fpanelclamp.jpg Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 4, 2012 Author Share Posted December 4, 2012 Here is a shot of the coffee table I am trying to match. There are a few other cherry pieces in this room too, but the walnut strips in this will be close to where the speakers are. Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 4, 2012 Author Share Posted December 4, 2012 Further progress fueled by Dragon's Milk... bass cabinets are clamped and the shells done. Prebuilt some bracing and they will get sanded for some preliminary finishing. Backs are done and the access hole for the cross over is done. Finishing started on those today. http://www.tinturtle.com/image.axd?picture=2012%2f11%2fbasscab_clampup2.jpg http://www.tinturtle.com/image.axd?picture=2012%2f11%2fbasscab_clampup.jpg Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 4, 2012 Author Share Posted December 4, 2012 Worked on a finish that I have used before and it seems nice on the backs. Boiled linseed oil that sits for 24 hours. Then 3 coats of hand rubbed General Finish Arm-R-Seal gloss, steel wool between each coat. Then sand with 320 and apply 2 more coats of Arm-R-Seal semi-gloss. Accompanied by a Pipeworks Hyperdog. http://www.tinturtle.com/image.axd?picture=2012%2f12%2fbacks.jpg The bottom cabinets have the ports to the upper chamber cut, as well as the middle piece. A template was made from mdf and then the final dimension was cut with a pattern bit. I truly hate mdf, it is a complete mess. I have not done a project with it in a long time, and I had forgotten how much I hated it. I had to wear a respirator to mill this stuff, and once this project is done it will take a full day to clean out the shop. http://www.tinturtle.com/image.axd?picture=2012%2f12%2fbasscap_port.jpg Quote Link to comment Share on other sites More sharing options...
Dr Morbius Posted December 4, 2012 Share Posted December 4, 2012 That's looking good, can't wait to see more! Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted December 4, 2012 Share Posted December 4, 2012 Beautiful! Can't wait to see more. Nice joiner by the way. Quote Link to comment Share on other sites More sharing options...
juniper8 Posted December 4, 2012 Share Posted December 4, 2012 Tin Turtle, welcome to the board and nice work!!! Those cabs look different than most we have seen. Keep up the great work, keep the pictures coming and let us know how they SOUND!!!. Good luck!!! Quote Link to comment Share on other sites More sharing options...
Guest David H Posted December 4, 2012 Share Posted December 4, 2012 Looks great, keep up the nice work. Dave Oops....Welcome to the forum. Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 5, 2012 Author Share Posted December 5, 2012 Thanks guys, I hope they turn out well. Finished assembly on the upper cabs that will hold the tweeter and squawker horns. As an interesting aside I am posting a picture that shows the difference between solar kiln dried and a commercial kiln dried piece of walnut. Typically the large commercial kilns will use steam on their walnut to blend the colors and givea more uniform appearance. That makes builders happy. Unfortunately that process also dulls the walnut, and can make it almost grey. The piece you see here (vertical) came from my normal supplier who is a local guy and dries his in a solar kiln. Nice browns, banding.. thats what I like. The horizontal piece I picked up at the yard and was done the typical commercial way, thats why it looks duller. Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 9, 2012 Author Share Posted December 9, 2012 The lower enclosures were dampened with carpet padding and automotive headliner fabric. Just some minor dampening to breakup any resonance that might happen, and help to clean up things for a little more clarity. Final sanding prep using 400 grit and these cabinets are really looking great. I did a quick stacking of the components to check proportions and get some idea as to what they will look like complete. The most noteworthy part of the evening was the Goose Island Night Stalker. I've never seen this one before, and it was incredible. Quote Link to comment Share on other sites More sharing options...
Jay Registrar Posted December 9, 2012 Share Posted December 9, 2012 Three things. 1. Nice shop and work 2. Have to try that Dragon's Milk 3. I have a pair of the JBL 2600's in your picture, as my computer speakers-awesome. Keep the pics and narrative coming. Thanks Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 12, 2012 Author Share Posted December 12, 2012 I finished milling the motorboard assembly for the lower cabinet. It was not that difficult. I use double sided tape to attach the waste backing board to the MDF. This way it doesn't come loose when the final cut is taken and bind into router or other nastiness. Then I use a Jasper Circle Guide to cut out the 4 speaker holes. Here are the final parts. Everything gets screwed together and test fitted both to the speaker and the cabinet. Quote Link to comment Share on other sites More sharing options...
twistedcrankcammer Posted December 12, 2012 Share Posted December 12, 2012 Looks Great! Welcome to the Forum and thanks for sharing your prodject! Roger Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted December 13, 2012 Share Posted December 13, 2012 You've got some thoughtful cab design there, looks very nice. Looking forward to seeing more of the project. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted December 13, 2012 Share Posted December 13, 2012 They look very nice. What is going to be done about bracing the back? That is a pretty large panel area there. Also any cross or up and down bracing? Tightening it up with those large panels will keep the speaker from sounding like a box. Quote Link to comment Share on other sites More sharing options...
Tin Turtle Posted December 13, 2012 Author Share Posted December 13, 2012 This is what I was thinking of doing. 1) Upper back panel is an easy one, I just double the back with a full sheet of MDF, that gives it a 1.5" thickness. Then dampen it the same was as the lower cab. 2) Lower back panels is a bit more tricky as the crossover takes up almost the full vertical length about 5 inches wide. On either side of that I do strips of MDF and dampen. 3) The lower sides I am not too worried about, Those vent boxes take up 60 - 70% of the surface area, I built them sturdy, siliconed and screwed them to the sides. 4) The lower bottom has a footer panel of mdf that covers almost the entire area, so that is 1.5" thick. 5) The top of the lower cabinet is the weak point but there is the middle piece/seperator that goes between the cabs. That gets glued and screwed, then the top cabinets bottom gets glued and screwed. So the cutouts are large, but the middle section is 2.25 inches thick. Then the batting on the bottom goes all the way across, 1.25 inches tall by about .75 thick, and solid walnut. That is front and back. The batting in the top is the same dimension but solid beech. I am thinking it will be ok, but feel free to comment. 6) The top cabinet sides have MDF panels that slide in from the front and go back about 60% of the depth, full surface, and will get glued and screwed. I will add in enough to cover it full surface (1.5" thick). Dampen like the bottoms 7) The top will get some additional panels of MDF, not sure just what yet, but something that will both brace and break up that big surface area. I figure the sound is coming straight up those holes, so I want to have something that will break up any reflections. It will be a heavy sob, but I don't plan on moving it. I did get some large flat cabinet feet to lift it off my hardwood floor, but I am getting nervous about that. These things may weigh enough to mar the floor with the feet. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted December 13, 2012 Share Posted December 13, 2012 It might be better to build H braces, going from front to back and side to side. That will give better bracing than double thickness and not eat up interior volume. In a speaker I built, I actually used the port as the bracing across the middle of it with H bracing top and bottom Quote Link to comment Share on other sites More sharing options...
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