I commissioned the speaker cabinets to a local woodworker. He's very experienced with cabinet building as he produced all the local commercial speaker cabinets during the 90's and 00's before China entered the game.
The biggest deviation will be the bass reflex hole. This is going to be 64.5mm in diameter which is 2.54in. It's still within specs by Wayne's instructions but it's on the upper limit. In order to compensate a bit for this I asked him to make the tube 0.5mm shorter.
The construction will be on two stages. He is going to give the cabinet with the front plate unattached so I can do all the work needed. I am excepting this to end in about a month. I will then return the cabinet to him in order to attach the front plate and to paint it.
I just got back from the woodworker. Everything goes according to plan and I should have the units to do the work next week.
Things that worry me right now:
1) Working with fiberglass with full clothing outside with Greek weather (which right now reaches around 38C (that's 100F).
2) Installing the woofer in the finished cabinet. The cabinet maker plans to leave a very small tolerance to the recessed part and I don't even know how to grab it to lower in to the hole (without damaging the cabinet and the paintjob of course). Maybe I will make a hook with some string attached to the mounting holes in order to lower it and then remove it somehow, I really don't know
Wayne Parham Messages: 18792 Registered: January 2001
Illuminati (33rd Degree)
Looks great!
I empathize with you on the insulation. But you only have to do it once.
As for installing the woofers, I like to lay the cabinets on their backs and gently lower the woofers into position. It's easier to line up the mounting holes that way. Connect the wires beforehand, of course.
I often position the woofer at an angle - with an edge resting on the flush routed groove - and connect the wires. Then rotate it and lower it into position with the mounting holes aligned.
Thread the mounting screws several turns by hand. You want to make sure they aren't cross-threaded. If they are hard to turn - don't force them - investigate, perhaps taking them out and rotating the driver just a little bit to re-align the holes.
Wayne requires a pi logo to be present on every pi speaker and I think it's the least a pi speaker builder should do for their designer.
The issue is of course you can't just buy them at the grocery store. Initially I didn't know how they were going to be made but I knew I had to have the logo on a vector format. I asked Wayne and he supplied me the logo in a picture, apparently a scan of the original image which was made with paint.
I converted the image with an online converter, it's easy since its just black and white and the only thing that the algorithm has to worry about is the detection threshold. I then proceeded to construct them as 3D objects in Rhino, this is a 3D design software that I had no idea how it worked beforehand. It is heavily used in 3D printing apparently and it can produce an .stl file which is the thing you need in order to construct any of these things. This is the result, I was able to do it in an afternoon as a complete beginner, thank god for that.
I then explored different options on how to make them. The first solution was to make a 3d-printed cask and make them with 925 silver but it seems that laser cutting produces better results. So here they are in brass:
At this point these are going to be polished and then they're going to be platinum plated in order to get a decent color (grayish silver instead of this awful yellow).
Wayne when they are ready I'll send you a couple!
If everything goes well I am getting the cabinets tomorrow!
Wayne Parham Messages: 18792 Registered: January 2001
Illuminati (33rd Degree)
That looks awesome! I love those brass logos!
Rhino is a great 3D modeler, almost as popular as AutoCAD. We used it to make the 12Pi hornsub drawings.
Quick story, just for historical Pi trivia:
The original "π" logo - which is still in use today - was hand-drawn and made into a stencil. The stencil was used to mask the woodwork and allow us to apply the logo with enamel, prior to final finish using poly, lacquer or whatever. This is how we applied the logo on loudspeaker cabinets in the 1970s and 1980s.
Sometime in the 1990s, I scanned that stencil (or maybe a painted image made from it, I don't recall) and sent the image file to a shop that makes the vinyl logo decals we use today. They vectorized it for use in their CNC cutters.
I believe I sent that image file to you too, so you must have vectorized it as well.
I am sorry, there was obviously an error with my measurements. Diameter is around 64.5mm which is the upper tolerance limit. Total depth (including the front plate) is around 64.
After some tests I found that these small t-nut prongs, at least in mine, need pilot holes in order to go into the wood without bending. I used 1.5mm drill bit and just 2mm depth, all they need is just a little help. I am driving them down with an Allen screw and a washer. A Philips screw won't do, there's not enough torque. I am finishing this with some 5-min epoxy.
I am a bit troubled about crossover placement. I get that the best place would be the bottom, under a fiberglass flap. However I don't like this since I am afraid it's going to mess up the insulation near the port and I will have to mess with fiberglass in order to reach it. Would it be really bad if I mount it at the uninsulated side, vertically with 6 wood screws? Also Wayne if you do have a picture of a bottom-mounted 3pi crossover with insulation installed please share it here.
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