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I will be ordering the crossovers, driver, and odds and ends from CLD on Monday.  With the drivers actually in hand I should be able to more easily finalize the drawings.

Even without supporting any weight other than their own, the three points of 1/8th inch thickness on the baffles have me concerned.  Apparently it won’t be an issue to spread the woofers apart by another 1/8th, giving me a 1/4″.  I think that should give it enough strength that I can handle them safely.  I’m not concerned about them once they are laminated to the MDF.  But until I do, if I get the granite in a position where it wants to flex, those points would be the first to crack.  I don’t want any cracks.

Having let go of the all-granite idea, I’m still interested in doing something unique with the large part of the cabinet.  Anyone know a good way to apply faux leather to MDF?  Not that I’m expecting a response.  The only person who has been to this website other than me is someone with an IP address in East Rochester, N.Y. (hi, Jed).

  • Richard

    Hi Ben

    What type of granite are you using, 3cm or 2cm? I would strongly recommend 3cm if you want any chance at all of moving those with out breaking. I don’t envy you trying to move those baffles being so long and with such big holes.I broke several baffles building my various speakers in granite.

    I would also recommend rodding the sides of the baffles before you have them cut. Unrodded it is very unlikely they will crack, they will break. The rodding will hold the granite together and give you the opportunity to repair the crack. Depending on the color, a good fabricator can repair a crack and make it almost invisible.

    Have fun with the project, I look forward to seeing the progress.

    • Ben

      Hi Richard – hey, my first ever non-spam comment!

      Well, my plan right now was to use a 2CM remnant of Red Dragon. I’m not sure how common it is, it may be a relatively “new” stone. It is a deep red with some black. Your recent Troels Ellam build had a similar looking stone baffle. Couldn’t tell if it was the same or not, but you mentioned you didn’t know the name of it. Perhaps it is the same stuff.

      I hadn’t thought about rodding it – that is something to consider. I won’t be routing the stone at all. It will simply be a rectangle with circles, and I will build up some mdf rings to act as the mounting surface for the drivers and bring them to flush-depth. I’m planning on simple roundover on the edges, which I would do before cutting out the holes. Cut to size, profile, cut the holes. I’ll bring the speakers into the shop so I don’t have to transport the granite but a few feet before attaching to the cabinets. I may also have it cut with some ply as a backer to give some extra strength while lifting.

      I’m lucky enough to have found a remnant that is not really an appropriate size for anything, so the stone will likely be free or a couple bucks per ft. If it fails, it fails and I can go the traditional route, but I’m hoping I can get lucky. I’ll look into the rodding next week. What do you think though – if I had 6 or 8 hands evenly lifting, couldn’t it be done?

  • richard

    Red Dragon has been around a long time and is a very, very hard stone, this should work in your favor. Not the same as my Ellam build, Red Dragon is much harder.

    Cutting with a ply backer is a great idea, at the least it will allow you to move the part to a location that makes it easier to take the baffle easier to lift off the ply. I assume you are water jetting the baffle? If so you will likely be reducing your cutting speed to compensate for the hardness of the granite. Did I mention that Red Dragon is hard material? :) This stuff chews through finger bits like butter.

    Post some pics of the jetting, I am sure a lot of people would like to see how its done.

    Good luck!

    • Ben

      Yes – I was pleased when I learned Red Dragon was a hard stone. It is quite gorgeous. I talked to some people at work, where I will be having it waterjet, they concurred about the rodding. But I’ve only got .685″ from the edge to the nearest through-hole edge for the woofers. Is that enough? Would doing it there perhaps make it more vulnerable? I could conceivably make the baffle another 1/2 inch wide, which would give me almost an inch at that measurement, but I don’t think I could go more than that without influencing performance.

  • Mukund

    Nothing to do with my work, but very interesting. What made you choose the granite for a baffle?

    • Ben

      Mainly for the sake of doing something a little different, and the appearance. And I work for a place that makes it possible and cheap.