Got all the braces and the bottom of the speaker volume installed. Putting the bracing in really stiffens the panels. You can hear the difference when you do a knuckle rap test on the sides. The resonance of the panels is much higher in frequency after they are braced.
In addition to the shelf braces I also glued in stick bracing vertically on the sides as well as across the top and bottom.
A few posts back Bill asked how I was going to hold the crossover board from vibrating. The rear is securely fastened to the cabinet back. I could put T nuts in the front of the board and bolt it down from the underneath. This would be awkward for removing the board. I decided to hold it down in the front using some spring steel clips I had in my junk box. They fit under a cleat attached to the back side of the baffle and hold the board down onto the bottom of the box. This should do the trick. If not I can always bolt them down.
Heres the clips mounted on the front side of one of the boards.
Here is the board up against the cleat before seating it . The cleat has a 30degree slope on the bottom to help ease seating the board.
And here it is seated. The amount of force needed to seat the board is not that great but definitely holds it securely to the bottom of the box.
I've only built a few pairs of speakers over the years. Newform 645 cabinets, GR Research OB7's, a pair of subs and now these Pi 3s. I'm a bit out of practice as I haven't been doing much wood working in the past 2 or 3 years. The hardest part is yet to come. I always find finishing a set of speakers to be the hardest part. I'm going to paint these. I've done veneer in the past but with the size of these boxes it would be a lot of $ and time to veneer them.
Bill Epstein Messages: 1088 Registered: May 2009 Location: Smoky Mts. USA
Illuminati (2nd Degree)
BFP wrote on Tue, 28 January 2014 20:36
II've done veneer in the past but with the size of these boxes it would be a lot of $ and time to veneer them.
Awww, go for it...but make it easy on yourself, 4x8 sheets of NBS veneer from Tape Ease and contact cement. One sheet does it if you paint the backs.
I've done PPR, hide glue (lots), yellow heat bond(sucks!) and even 3M spray-on (disaster) on backed and raw veneer; contact has worked and held up best for me.
Those boxes look great in veneer Bill. I am still staying with the black paint. I've done this before on an equipment stand and it has held up remarkably well over 15years of use. A top coat or 2 of water based polyurethane has proven to be a tough finish that is easy to apply. These speakers will be in my dedicated listening room and don't need to have a furniture grade finish. My thought was that the black will look nice with the black horn and woofer. We'll see.
Back panels glued on. I used a couple of screws in the centre at the Baltic Birch window braces to make sure the back was pulled in tight.
Next I added some temporary feet so i could move the boxes around easier for painting etc.
I installed the 4 magnet washers into the front panel just below the surface. Sorry for the blurry photo. The magnets will be in the grills. I got these at Lee valley. They have sets of 4 magnets, cups and washers in various sizes. These are 1/2". The weight of the grill will be sitting on a plinth attached to the lower front of the speaker so the magnets only need to hold the grill in against the baffle.
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