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Speakers: MUN17-3W

I'm still battling with how to construct the front section of the upper cabinets.

I don't particularly like the all black finish of Troels' original build. But it's unlikely I would be able to veneer all the angles to a presentable standard. The other two options I'd considered are : a) using some burl wood slabs I have lying around and doing a thick epoxy pour over everything in a mould, then carving out from there; or b) using some spare oak worktop I have to construct the main frame, with some valcromat as the front baffle.

I'm going to try option B first, as it's the cheaper option. If it doesn't turn out great I can always attempt to veneer over the top... My main concern is having visible blockwork in the oak which I really dislike.
 
Another resin pour after breakfast.



I'm using a slow cure epoxy, one of the upsides of which is that almost all the air bubbles pop themselves, leaving a glass-like finish. This should make it very easy to apply the felt / damping
 
So, now 7 months in. I've almost finished the easy / fun stuff. The rest is going to be a bit of a slog.

The current ongoing battle is figuring out how to rebate and punch through the tweeter. My jig doesn't go down to the size needed, which is a 120mm rebate and a hole of circa 95mm. By an odd twist of fate, the circle punched out from the mid driver cuts seems to be exactly 120mm but I'm not sure if that's useful or not! I think I could calculate the diameter of a flat bottom router bit, then rebate this width out of one side of the circle, then use a flush trim bit on the other side to level the whole circle down to size. In theory I could then use this as a template to cut the rebate...

I've also decided that having these crossovers mounted in the cabinet isn't ideal. Mainly due to size - there's nowhere sensible to put them in the upper cabinet, particularly as they would need to be removed from the driver hole and they will not fit! I'm therefore trying to decide on a suitable box design to match the cabinets...
 
fraser. said:
So, now 7 months in. I've almost finished the easy / fun stuff. The rest is going to be a bit of a slog.

The current ongoing battle is figuring out how to rebate and punch through the tweeter. My jig doesn't go down to the size needed, which is a 120mm rebate and a hole of circa 95mm.
Click to expand...
Routing is the fun part, as is veneering and finishing.

Have a look at this post of mine on how you can make a variable jig to cut holes for small drivers.
 
Progress stalled a little as I'm waiting on some bits to arrive. Just about finished the leg for the desk though...

 
Fern-Roby-Products-24.jpg
Nice you could do Fern&Roby beam speaker clones next!

 
My first attempt at routing for the tweeters went about as badly as it could have. The rebate is far too big, and the punch-out is way too big leaving hardly anything for the screws to attach to! In some ways this is a relief as I don't think I ever would've been happy with the cabinet constructed in this way... My heart is pretty much set on using a solid chunk of oak and resin for the upper cabinet. With the pressure off I quickly chucked (quite literally) the drivers into a baffle, hammered it into a frame, and lashed together the crossovers to get them up and running.

Temporary testing:




I'm currently running the bass drivers wide open until I get the hypex modules set up. The bass is a bit all over the place as you'd expect, but the quality of the mids and highs is already evident. This is the first time the crossovers or drivers have seen any life so a long way to go for them.

More exciting - leg in place!

 
The starting point for a hardwood upper cabinet / baffle are these old burl off-cuts from my woodman. Due to shape they were very cheap and i've had them sitting around for ages. They are both elm, but very different in colour!

Bits of tree -
https://ibb.co/nBnhHv2][/url]

Rough planing -
https://ibb.co/bQKYwfv][/url]

After a rough sanding you can see this would finish up quite nicely also
https://ibb.co/v4tyrW6][/url]

So i cut them down into roughly baffle-size shapes. I'm still not sure which I prefer; light or dark. I suspect one the lighter one has been cleaned out, with the voids filled with black epoxy it would look really nice. The figuring on the dark one is spectacular though. I have some other small bits and bobs to make so might save it for that.
https://ibb.co/jvPdjNm][/url]

https://ibb.co/9V0m7tY][/url]

https://ibb.co/b5NhCyt][/url]

https://ibb.co/5B38cGy][/url]

https://ibb.co/kXRdQcv][/url]

https://ibb.co/fFCh97n][/url]

https://ibb.co/CsSKMrs][/url]


I also cut out the sheet material for making some crossover boxes. I'll use this material all around aside from the front panel, for which i'll do something nice.
https://ibb.co/qCGgSXS][/url]

The intention is to make something similar to a naim shoebox, but with a wood front panel.
https://ibb.co/pjR5s85][/url]
 
I don't have any big tools so to flatten the wood i made a little jig up and used a flattening router bit, running shallow passes over each side until the low spots / high spots were gone. As the boards are now quite small this was quite easy to do and didn't need a huge amount of material removing.

However.... having done a couple and splashed some water on them to see what they might end up like... I don't like them at all :(

I think i'd get sick of looking at them after 5 minutes!

Mid-flattening:
https://ibb.co/rvyv0Fm][/url]
https://ibb.co/6F0HWB5][/url]

After some waterworks:

https://ibb.co/wRtV8TR][/url]
https://ibb.co/nbHJ50q][/url]
https://ibb.co/7GPPBxy][/url]
https://ibb.co/ZW2pBCZ][/url]

They remind me a bit of victorian furniture. I'm realising i'm more of a boring oak type. Nevermind. I'll find a use for them somewhere, just not here.
 
fraser. said:
I'm realising i'm more of a boring oak type. Nevermind. I'll find a use for them somewhere, just not here.
Click to expand...
Wise decision. You want a material that is structurally more consistent to function as a stable foundation for your drivers.
 
Here's some oak to attempt with instead. It looks like a reasonably good match with the veneer on the lower baffle too, at least in terms of colour.

 
I might not have been clear in my last post. I DO NOT recommend the use of natural timber for the baffle. It will expand and contract with humidity changes, leading to buckling and cracking when fastened with rigid drivers.
 
James said:
I might not have been clear in my last post. I DO NOT recommend the use of natural timber for the baffle. It will expand and contract with humidity changes, leading to buckling and cracking when fastened with rigid drivers.
Click to expand...
Everything I've read on the subject supports what James says. I've read that it's possible to use solid timbers for sides and top/bottom, if the grain is running in the same direction, because the principal movement will be across the grain, and all the pieces will shrink/expand together. Not tried it yet though.
 
irb said:
Everything I've read on the subject supports what James says. I've read that it's possible to use solid timbers for sides and top/bottom, if the grain is running in the same direction, because the principal movement will be across the grain, and all the pieces will shrink/expand together. Not tried it yet though.
Click to expand...
My understanding is the same - the consensus generally seems to be it's a bad idea. For what it's worth I wouldn't be constructing a box in the traditional sense... If I do go ahead with timber for the front section I would essentially be sticking together a very thick front baffle, made of 3 or 4 pieces of wood glued face to face.
 
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fraser. said:
If I do go ahead with timber for the front section I would essentially be sticking together a very thick front baffle, made of 3 or 4 pieces of wood glued face to face.
Click to expand...
You might mitigate movement by cross-plying. Good luck with routing the driver holes though. I'd still strongly advise against it, but like your children, I sense you will do it any way.
 
As I'm also in need of a rack to house some gear on, I've decided to use the oak for the shelves. Similar to ladder shelves but smaller and chunkier.

Roughly cut to size so far:





For the upper baffle I've decided on a slightly different approach. I'm going to use some old worktop I've had lying around for ages. In the first instance I'm going to veneer the front face only, and leave the exposed timber on the angles. If this looks naff I'll try veneering over these too.

After living with them for a couple of months I've also been thinking I've made a mistake with the bass cabinet aesthetics also. I like the idea in principle but I think the dimensions ruin it a little... Maybe if I'd used a valcromat inlay for the whole front it would look better. Regardless, I'm going to veneer over the whole thing!
 
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